Prior salpingectomy impairs the retrieved oocyte number in in vitro fertilization cycles of women under 35 years old without optimal ovarian reserve.

STUDY
OBJECTIVE: The impairment of the ovarian response in in vitro fertilization (IVF) cycles after salpingectomy remains contentious. Therefore, we investigated whether a history of salpingectomy affects the number of oocytes retrieved in women undergoing IVF in comparison with the number in women without underlying tubal disease.
DESIGN: Case-control study (Canadian Task Force Classification II-2).
SETTING: A tertiary hospital-affiliated fertility center. PATIENTS: Fifty-four women aged <35 years with a history of salpingectomy and 59 age-matched women without tubal disease.
INTERVENTIONS: Gonadotropin-releasing hormone antagonist protocol for controlled ovarian stimulation and transvaginal oocyte retrieval.
MEASUREMENTS AND MAIN RESULTS: The antral follicle count (AFC), anti-Müllerian hormone (AMH) levels, and the number of retrieved oocytes were significantly lower in women with prior salpingectomy than in women without tubal disease. Day-3 follicle-stimulating hormone (FSH) levels, total gonadotropin dosage, and stimulation days did not significantly differ between the groups. The indications of salpingectomy (i.e., hydrosalpinx and ectopic pregnancy) did not differ significantly in terms of ovarian response or reserve among women with salpingectomy history. A history of salpingectomy and other factors related to ovarian response in IVF, such as age, AMH, AFC, day-3 FSH, and total gonadotropin dose, were significantly correlated with the number of oocytes retrieved by univariate regression analysis. In the multivariate-adjusted model after controlling all the above-mentioned variables, only AFC and AMH levels continued to exhibit significant associations with the number of retrieved oocytes. In a subgroup analysis, the negative impact of prior salpingectomy on the number of retrieved oocytes was especially significant in women with suboptimal ovarian reserves (defined as AMH < 4 ng/mL), regardless of the indication of salpingectomy or whether salpingectomy was bilateral or unilateral.
CONCLUSION: A negative effect on the number of retrieved oocytes in the subsequent IVF cycle after salpingectomy is more likely in women aged <35 years with suboptimal ovarian reserve. Nevertheless, postsurgical AMH and AFC levels still possess a more direct predictive value on ovarian response than the history of salpingectomy.

Introduction

Tubal factor infertility is among the most common causes of female infertility, affecting approximately 30%–35% of women with infertility [1]. Tubal factor infertility can be caused by acute salpingitis, endometriosis, and surgical adhesion, which result in chronic inflammation and distal tubal adhesive disease. Women who require tubal surgery for various conditions tend to select salpingectomy over salpingostomy or proximal tubal ligation to reduce the risk of future epithelial ovarian cancer, incomplete treatment, and reoperation due to postsurgical adhesion or persistent disease [2].

A hydrosalpinx occurs when a blocked fallopian tube fills with fluid, and it is a common disease in women who have undergone in vitro fertilization (IVF) or embryo transfer. Previous in vivo and in vitro studies have revealed that the content of hydrosalpinx fluid may be toxic to an embryo and adversely affect subsequent embryo development and implantation [3-6]. Hydrosalpinges are reportedly associated with a 50% lower chance of implantation and a twofold increased risk of pregnancy loss in IVF pregnancies [7]. Studies have suggested that prophylactic salpingectomy or proximal tubal obstruction for hydrosalpinges prior to IVF helps increase the ongoing pregnancy and live birth rates [2, 8–11]. However, because of the profound anastomosis of the blood supply between the ovary and fallopian tubes, salpingectomy and other tubal surgeries have the potential to adversely affect fertility and ovarian reserve, causing concern for clinicians and patients [2]. Nevertheless, the data on ovarian response and ovarian reserve after salpingectomy have often been contradictory [2, 12, 13].

Ectopic tubal pregnancy is associated with chronic salpingitis, and typical treatment includes salpingectomy, especially when evidence of rupture is present [14]. Compared with salpingostomy, salpingectomy may be superior in eliminating the risks of persistent and repeat ectopic pregnancies and reducing the number of hospital visits and frequency of blood sampling [14, 15]. In addition to the concern regarding ovarian damage in patients receiving salpingectomy for hydrosalpinges, many researchers have investigated whether disruptions to the descending vasculature along with the removed fallopian tube could impair ovarian function in ectopic pregnancy; however, disparate results have been obtained [15, 16].

A randomized controlled trial of women with hydrosalpinges [17] indicated lower ovarian reserve, lower numbers of retrieved oocytes, and higher gonadotropin stimulation dosages in patients who underwent salpingectomy compared with those who underwent proximal tubal occlusion. An experimental study revealed that total salpingectomy in rats leads to more significant damage than proximal tubal occlusion in ovarian histopathology and the cholinergic system [18]. Another study also indicated that the unilateral total salpingectomy procedure can be detrimental to ipsilateral ovarian tissue as a result of ischemia–reperfusion injury [19].

Nonetheless, most meta-analyses have been unable to demonstrate a significant detrimental effect of salpingectomy on ovarian reserve and ovarian response in IVF, regardless of the indications of salpingectomy [2, 8–12, 15]. Moreover, studies investigating the effect of salpingectomy on ovarian reserve have typically been designed to compare the surrogate markers of the ovarian reserve or ovarian response of IVF patients before and after surgery within a short period or have limited the study population to patients with tubal disease. Furthermore, most of these studies have not controlled for the ovarian stimulation protocol.

In a study comparing women with infertility with and without history of salpingectomy for known tubal disease [13], history of salpingectomy was associated with a lower antral follicle count (AFC) in the women with infertility who were 35–39 years old. The study did not report a reduction of AFC related to a history of salpingectomy in women under 35 years old, implying that decline in age-related ovarian reserve may contribute to the impairment of ovarian reserve in women with a history of salpingectomy. However, the study did not include a subgroup analysis to investigate whether the effect of salpingectomy was more pronounced in women under the age of 35 years with suboptimal ovarian reserve. In the present study, we (1) investigated whether history of salpingectomy affected the number of oocytes in women undergoing IVF compared with women without underlying tubal disease by using conventional hysterosalpingographic evaluation and (2) examined whether this effect differed depending on ovarian reserve.

The outcomes considered in this study were the indication of salpingectomy, bilateral versus unilateral salpingectomy, and distinct levels of baseline ovarian reserve, which may have influenced the effect of salpingectomy on the number of retrieved oocytes.

Materials and methods

Setting and design

This retrospective case–control study was approved by the Institutional Review Board of Shin Kong Wu Huo-Shih Memorial Hospital (Approval number: 20210704R). All clinical data were fully anonymized before we accessed them and the inform consent was waived because of the retrospective nature.

The research was conducted in the Infertility Center of the Department of Obstetrics and Gynecology at Shin Kong Wu Huo-Shih Memorial Hospital from January 2012 through December 2019. During this period, 1096 patients aged under 35 years received IVF treatment in our center, including 102 patients with a history of salpingectomy. For the final analysis, the study group consisted of 54 participants after women who did not meet our inclusion criteria or lacked complete surgical records were excluded. Another 59 participants were randomly selected as age-matched controls (by 3-year age strata) from a consecutive series of 606 women with conventional hysterosalpingography results; these participants received IVF because of male fertility factors or unexplained infertility. For all the recruited participants, the data for controlled ovarian stimulations were only collected from the first IVF cycle.

The study group was further divided into subgroups according to the indication for salpingectomy (hydrosalpinx or ectopic pregnancy) and the type of salpingectomy (bilateral or unilateral). The inclusion criteria of all the enrolled control and study participants were as follows: (1) aged 20–34 years, (2) had a regular menstrual cycle, and (3) treated with a gonadotropin-releasing hormone (GnRH) antagonist protocol. Patients were excluded if they had a history of ovarian surgery or diseases that affect ovarian function, namely endometriosis, ovarian tumors, polycystic ovarian syndrome, and autoimmune disease. Patients were excluded from the control group if tubal factors were present.

Salpingectomy

All the enrolled patients who required tubal surgery received laparoscopic salpingectomy from an experienced gynecologic surgeon who endeavored to incise the smallest possible area within the mesosalpinges. We excluded patients who received segmental salpingectomy for severe pelvic adhesion or other inoperable conditions.

Controlled ovarian stimulation and outcome measures

All the enrolled patients were treated with an individualized GnRH antagonist protocol [20] for controlled ovarian stimulation before oocyte retrieval, which was performed as described previously. In brief, exogenous recombinant follicle-stimulating hormone (rFSH, Gonal F; Merck Serono, Germany) was administered at a dose of 150–375 IU/day depending on the patient’s age, body mass index (BMI), ovarian reserve, and response. Serial transvaginal ultrasound scans and concurrent serum luteinizing hormone, estradiol (E2), and progesterone levels were used to assess the ovarian response of all the enrolled patients and adjust the gonadotrophin dosage accordingly. The GnRH antagonist protocol (Cetrotide; Merk Serono, Geneva, Switzerland) was commenced on stimulation day 6 or when the dominant follicle reached 14 mm, whichever occurred first. Administration of one dose of 6500 IU hCG (Ovidrel; Merck Serono) or two 0.1 mg doses of triptorelin (Decapeptyl; Ferring Pharmaceuticals) was performed for ovulation trigger when two or more follicles reached 18 mm in diameter, or three follicles reached 17 mm in diameter. Oocyte retrieval was performed 34–36 hours after triggering.

The number of retrieved oocytes, total administered dose of gonadotropin, and total days of ovarian stimulation were recorded. The biomarkers anti-Müllerian hormone (AMH), day-3 FSH, and AFC on menstrual cycle day 2 or 3 were also measured before patients entered the IVF cycle to predict ovarian reserve. Subgroup analyses were conducted to evaluate the association between the number of retrieved oocytes and salpingectomy in women with infertility undergoing IVF with various baseline ovarian reserves. The cutoff value for AFC (12 follicles) was based on the calculated median AFC of all enrolled patients, and the cutoff value for AMH (4 ng/mL) was based on the reported 75th percentile of AMH levels of generally healthy Chinese women aged 35 years. The AMH levels between 35 to 36 year-old Chinese women lies between 4.229 to 3.973 ng/mL in the 75th percentile [21].

Statistical analysis

Numeric variables are presented as untransformed means ± standard deviations unless indicated otherwise. Between-group comparisons were conducted using a Mann–Whitney U test or a Kruskal–Wallis test with the Hochberg method for post hoc testing. The Shapiro–Wilk W test was used to determine the nature of the data distribution. Continuous variables were log-transformed before univariate and multivariate linear regression analyses. A P value of <0.05 was considered significant. All statistical analyses were performed using SPSS 17.0 (SPSS, Inc., Chicago, IL, USA).

Results

Fifty-four women in their first IVF cycle with a history of salpingectomy along with 59 age-matched controls without prior tubal disease were included in the final analysis. Among the women with a history of salpingectomy, the indication for salpingectomy was ectopic pregnancy in 26 patients and hydrosalpinx in 28 patients. As detailed in Table 1, the women with prior salpingectomy had significantly lower AFC and AMH levels than the controls without tubal disease. Age, BMI, day-3 FSH levels, total gonadotropin dose, and total stimulation days did not significantly differ between the two groups. No significant differences in age, BMI, or baseline surrogate markers of ovarian reserve and ovarian response (i.e., AMH, AFC, day-3 FSH levels, total gonadotropin dose, and total stimulation days) were observed between the patients with distinct indications of salpingectomy (Table 1).

Table 1

Basic characteristics of all enrolled patients at the time of recruitment.

Study group (with history of salpingectomy)					Control group (without tubal diseases)
Reason for salpingectomy	Ectopic pregnancy	Hydrosalpinx	P value*	All		P value**
Number	26	28	-	54	59	-
Age (years)	28.6 ± 4.9	30.8 ± 2.6	0.09	29.7 ± 4.0	29.3 ± 1.8	0.25
BMI (kg/m2)	20.9 ± 2.5	20.0 ± 4.5	0.67	20.4 ± 3.7	20.8 ± 2.1	0.76
AFC	11.3 ± 7.2	10.4 ± 6.2	0.48	10.8 ± 6.6	13.2 ± 5.2	0.005
Day3 FSH (mIU/mL)	7.6 ± 1.8	7.5 ± 2.5	0.37	7.5 ± 2.2	7.4 ± 1.7	0.93
AMH (ng/mL)	5.4 ± 2.7	5.2 ± 3.9	0.44	5.3 ± 3.3	6.6 ± 3.5	0.039
Total gonadotropin dose (IU)	2303.8 ± 763.6	2528.6 ± 1051.1	0.59	2420.4 ± 922.4	2193.2 ± 647.3	0.30
Total stimulation days	9.8 ± 1.2	9.9 ± 1.3	0.77	9.8 ± 1.3	9.9 ± 1.3	0.59

BMI: body mass index; AFC: antral follicle count; AMH: anti-Müllerian hormone; FSH: follicle-stimulating hormone.

* Statistical comparisons between participants with distinct indications of salpingectomy.

** Statistical comparisons between the control and study groups.

The univariate analysis suggested that the number of retrieved oocytes was significantly and negatively associated with history of salpingectomy, age, day-3 FSH levels, and total gonadotropin dose, whereas a significant positive association was observed between the number of retrieved oocytes and AFC and AMH levels (Table 2). The aforementioned associations between the number of retrieved oocytes and the given variables remained after the model was adjusted for age and BMI. However, in the multivariate-adjusted complete model, only AFC and AMH levels continued to exhibit significant associations with the number of oocytes (Table 2).

Table 2

Results of univariate and multivariate analysis of the association between the number of retrieved oocytes and history of salpingectomy, as well as other variables involved in predicting the ovarian response in IVF.

	Univariate analysis		Multivariate analysis
			Age adjusted		BMI adjusted		Full model
Variables	β	P value	β	P value	β	P value	β	P value
History of salpingectomy	-0.2405	0.005	-0.2353	0.005	-0.2369	0.007	-0.0415	0.56
ln(Age)	-0.8390	0.004	-	-	-0.8574	0.034	-0.0053	0.99
ln(BMI)	-0.1391	0.45	-0.1579	0.38	-	-	-0.1152	0.37
ln(AFC)	0.5887	<0.001	0.5744	<0.001	0.5791	<0.001	0.3441	<0.001
ln(Day3 FSH)	-0.4541	0.008	-0.5124	0.002	-0.4125	0.018	-0.1934	0.18
ln(AMH)	0.4335	<0.001	0.4366	<0.001	0.4309	<0.001	0.2726	<0.001
ln(Total gonadotropin dose)	-0.4881	<0.001	-0.4688	<0.001	-0.4648	<0.001	-0.1442	0.39
ln(Total stimulation days)	0.3339	0.34	0.3461	0.34	0.3586	0.32	0.7669	0.021

BMI: body mass index; AFC: antral follicle count; AMH: anti-Müllerian hormone; FSH: follicle-stimulating hormone.

The number of retrieved oocytes was significantly lower in patients in the study group than in those without a history of salpingectomy (10.4 ± 5.2 vs. 12.2 ± 3.8, P = .006; Fig 1A). To further investigate the number of retrieved oocytes according to levels of ovarian reserve, participant AMH level and AFC were further divided into two groups to compare the numbers of retrieved oocytes in women with and without salpingectomy history and with different indications for the procedure. As indicated in Table 3 and Fig 1B, prior salpingectomy history was associated with significantly lower retrieved oocyte numbers in women with AMH < 4 ng/mL and AFC < 12, but not in women with AMH ≥ 4 ng/mL or AFC ≥ 12. Regardless of baseline AMH level and AFC, the retrieved oocyte number did not differ significantly between patients with distinct indications of salpingectomy (i.e., ectopic pregnancy vs. hydrosalpinx; Table 3 and Fig 1C).

Fig 1

Comparison of total numbers of retrieved oocytes between study and control groups.

(A) Total number of retrieved oocytes in IVF was significantly higher in the enrolled women as a whole than in those with a history of salpingectomy. Subgroup analysis of women with (B) AMH < 4 ng/mL and (C) AMH ≥ 4 ng/mL. The study and control groups comprised women with a history of salpingectomy and women without tubal disease, respectively. Values presented as mean ± SD and were provided in the minimal data set of supplementary files. Statistical analysis was conducted by Mann–Whitney U test. P values presented as an actual number when there was a significant difference. N.S: not significant; AMH: anti-Müllerian hormone.

Table 3

Subgroup analysis by baseline ovarian reserve indicating the number of retrieved oocytes in women with and without salpingectomy and in women with salpingectomy and distinct indications (i.e., ectopic pregnancy vs. hydrosalpinx).

Study subjects (with history of salpingectomy)					Control subjects (without tubal diseases)
	Ectopic pregnancy	Hydrosalpinx	P value*	All		P value**
AMH < 4 (ng/mL)
Oocyte number	6.9 ± 2.9	6.0 ± 3.4	0.75	6.4 ± 3.1	9.9 ± 3.0	0.007
AMH ≥ 4 (ng/mL)
Oocyte number	12.8 ± 3.7	13.3 ± 5.8	0.96	13.1 ± 4.8	12.8 ± 3.7	0.52
AFC < 12
Oocyte number	8.2 ± 2.9	8.0 ± 5.2	0.31	8.1 ± 4.4	10.2 ± 3.1	0.004
AFC ≥ 12
Oocyte number	12.8 ± 3.5	15.2 ± 5.3	0.30	13.8 ± 4.4	13.4 ± 3.7	0.56

AFC: antral follicle count; AMH: anti-Müllerian hormone.

* Statistical comparisons between participants with distinct indications of salpingectomy.

** Statistical comparisons between the control and study groups.

The women with salpingectomy history because of hydrosalpinx had a significantly lower retrieved oocyte number than the women without a history of tubal disease (Fig 2A). This association was stronger in the women with AMH < 4 ng/mL (Fig 2B), but not in those with AMH ≥ 4 ng/mL (Fig 2C). In addition, the women with unilateral salpingectomy history had a significantly lower number of retrieved oocytes than the women without tubal disease (Fig 3A). Furthermore, this association was significant in women with AMH < 4 ng/mL (Fig 3B) but not in those with AMH ≥ 4 ng/mL (Fig 3C).

Fig 2

Total number of retrieved oocytes in women with distinct indications of salpingectomy.

Comparison of the differences in the numbers of retrieved oocytes between women without tubal disease (control) and women with different indications for prior salpingectomy (i.e., hydrosalpinx and ectopic pregnancy) (A) in all enrolled participants, (B) in women with AMH < 4 ng/mL, and (C) in women with AMH ≥ 4 ng/mL. Values were provided in the minimal data set of supplementary files. Statistical analysis was by Kruskal–Wallis test with the Hochberg post hoc testing. AMH: anti-Müllerian hormone.

Fig 3

Total numbers of retrieved oocytes in those with bilateral, unilateral, and without salpingectomy histories.

Differences in the retrieved oocyte numbers in women with bilateral salpingectomy, unilateral salpingectomy, and without salpingectomy (A) in all enrolled subjects, (B) in women with AMH < 4 ng/mL, and (C) in women with AMH ≥ 4 ng/mL. AMH: anti-Müllerian hormone.

Discussion

In this study, the number of retrieved oocytes in young patients with a history of salpingectomy who were undergoing IVF was significantly lower than that in the controls without tubal disease. In addition, the subgroup analysis revealed that the reduction in the retrieved oocyte number related to prior salpingectomy was prominent in patients without optimal baseline ovarian reserve. This study investigated the effect of prior salpingectomy and its indications on the subsequent ovarian response in women undergoing IVF. To our knowledge, this is the first study of such topics that specifically focused on patients younger than 35-year-old who received a GnRH antagonist protocol for controlled ovarian stimulation, compared the study population with a control group that did not have underlying tubal disease, and examined the effect of baseline ovarian reserve.

Several studies have reported a beneficial effect of salpingectomy on embryo implantation and clinical pregnancy rate in women with infertility and hydrosalpinges [7-9]. However, the potential damage in the vascular perfusion of the ovary due to salpingectomy is concerning [2]. In a randomized controlled trial, proximal tubal obstruction outperformed salpingectomy for preserving ovarian reserve in patients with hydrosalpinges, further demonstrating the potentially harmful effect of aggressive salpingectomy on this reserve [17]. Nevertheless, salpingectomy procedures are becoming increasingly common for various conditions in young women who undergo gynecologic surgery to avoid persistent disease or reduce the risk of future ovarian malignancy. Therefore, a thorough understanding of whether this surgical intervention affects the subsequent ovarian reserve and ovarian response is warranted to support future fertility and medical considerations.

Previous research has reported that a longer duration of ovarian stimulation and a higher dose of gonadotropin was required for IVF in women who underwent salpingectomy than in those who did not [22], especially for those in which ectopic pregnancy is the indication [12]. Most studies, including meta-analyses, have reported no significant differences in terms of ovarian reserve (represented by AMH, AFC, and day-2 or day-3 FSH levels) or the ovarian response (represented by the number of oocytes retrieved, duration of ovarian stimulation, and dose of gonadotropin in IVF before and after salpingectomy) [2, 8, 9, 11, 12, 15, 23], regardless of the indication of salpingectomy [15, 23]. However, these studies have mainly compared the ovarian reserve before and after surgery and were limited to populations with underlying tubal disease and middle-aged women. Therefore, the negative effect of salpingectomy on ovarian function may not have been detectable in these previous study populations.

The present study demonstrates that women without an optimal baseline ovarian reserve may be more vulnerable to damage from salpingectomy. For women with an optimal ovarian reserve and a large follicle pool, a history of salpingectomy did not affect the number of retrieved oocytes in subsequent IVF cycles. Similar results were observed in a retrospective study [13], which revealed that in IVF patients aged 35–39 years, the AFC was lower in patients with a history of salpingectomy than in those without a history of salpingectomy; however, the study did not further stratify patients under the age of 35 with distinct baseline ovarian reserves. Moreover, in the study of Chen et al., the researchers selected patients with tubal disease as controls, which may have lessened the effect of salpingectomy, for underlying tubal disease may have been a confounding factor for reduced ovarian reserve. Therefore, this may be unable to demonstrate the difference in ovarian response for patients with salpingectomy history and a sufficient baseline ovarian reserve or those under 35 years old. Nonetheless, these findings substantiate the negative effect of salpingectomy on women with suboptimal baseline ovarian reserve; therefore, baseline ovarian reserves should be considered in treatment strategy recommendations for women.

The primary outcome in our study was actual retrieved oocyte number. We contend that to obtain more embryos, using retrieved oocyte number as a reference would be superior to using circulating surrogate markers of ovarian reserve. The number of retrieved oocytes was also positively correlated with pregnancy outcome. The number of retrieved oocytes in relation to the total dose of ovarian stimulation drugs could reflect the ovarian response. However, a retrospective study [24] reported a negative effect of salpingectomy history on AMH levels but not on the retrieved oocyte number for women with infertility, which differs from our study results. Nevertheless, distinct from our study, short and minimal stimulation protocols were applied for controlled ovarian hyperstimulation in that retrospective study. In our study, we solely used the GnRH antagonist protocol for controlled ovarian stimulation and adjusted the dosage to obtain the optimal response. Variations in stimulation protocol, total gonadotropin dosage, stimulation interval, baseline ovarian reserve, and blood flow in the ovaries may have influenced the numbers of retrieved oocytes.

Along with concern about damage of periovarian vascular perfusion and potential thermal damage by an electrocauterization device during salpingectomy, underlying fallopian tube diseases that lead to hydrosalpinges and ectopic pregnancy may also contribute to impaired ovarian response. Pelvic inflammatory disease and mild peritoneal endometriosis are common causes of tubal adhesion or malfunction. In patients without prior surgical intervention, chronic pelvic inflammation and tubal obstruction reportedly reduce ovarian reserves, as indicated by lower AMH levels in these patients than in healthy women with infertility [25]. In addition, direct damage to the gonads by iron deposition has been demonstrated in human and animal studies [26-28]. A recent meta-analysis also revealed a reduced ovarian reserve in women with endometriosis, as indicated by lower AFC and AMH levels, regardless of the presence of endometriotic ovarian cysts [29]. However, there were several limitations in our study. Because of limited case numbers and our retrospective study design, we did not consider tubal disease itself as a potential confounding factor affecting ovarian response. Untreated hydrosalpinges can also hinder the procedure of transvaginal oocyte retrieval and increase the risk of infection. In addition, when considering salpingectomy’s effect on ovarian response, designing the study to compare retrieved oocyte numbers before and after tubal surgery would not be feasible in the ectopic group because of the emergency nature of the disease. Also, the univariate analysis in our study indicated that factors such as salpingectomy history, AMH, and AFC were all significantly associated with the number of retrieved oocytes. However, the AMH and AFC had more direct and stronger correlations with the retrieved oocyte number than did history of salpingectomy, the effect of salpingectomy history was no longer significant after applying the full model of multivariate analysis. In conclusion, compared with age-matched women without tubal disease, young women with a history of salpingectomy (with either ectopic pregnancy or hydrosalpinx indications) had a significantly lower number of retrieved oocytes during IVF, and this was especially evident in women without a large ovarian follicle pool. Our study findings suggest that greater attention should be directed toward ovarian response in women with infertility, without sufficient ovarian reserves, and with a history of salpingectomy because of their vulnerability to salpingectomy-related damage.

(DOCX)

Click here for additional data file.

24 Nov 2021

PONE-D-21-34495

Prior Salpingectomy Impairs the Retrieved Oocyte Number in In Vitro Fertilization Cycles of Women Under 35 Years Old Without Optimal Ovarian Reserve :  a retrospective study

PLOS ONE

Dear Dr. Ho,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

==============================

ACADEMIC EDITOR: This study investigating the association between the history of salpingectomy and the number of oocytes in women undergoing IVF has some issues that need to be addressed. Specifically, 2. the English needs a revision; 2. The authors should convince the reader that there were no selection biases; 3. Limits of the study needs to be discussed; 4. Several comparisons were performed. Please perform a Bonferroni's correction. All the issues raised by the Reviewers should be carefully addressed.

==============================

Please submit your revised manuscript by Jan 08 2022 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.

A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.

An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols.

We look forward to receiving your revised manuscript.

Kind regards,

Paola Viganò

Academic Editor

PLOS ONE

Journal Requirements:

When submitting your revision, we need you to address these additional requirements.

1. Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. The PLOS ONE style templates can be found at

https://journals.plos.org/plosone/s/file?id=wjVg/PLOSOne_formatting_sample_main_body.pdf and

https://journals.plos.org/plosone/s/file?id=ba62/PLOSOne_formatting_sample_title_authors_affiliations.pdf

2. Please provide additional details regarding participant consent. In the ethics statement in the Methods and online submission information, please ensure that you have specified (1) whether consent was informed and (2) what type you obtained (for instance, written or verbal, and if verbal, how it was documented and witnessed). If your study included minors, state whether you obtained consent from parents or guardians. If the need for consent was waived by the ethics committee, please include this information.

If you are reporting a retrospective study of medical records or archived samples, please ensure that you have discussed whether all data were fully anonymized before you accessed them and/or whether the IRB or ethics committee waived the requirement for informed consent. If patients provided informed written consent to have data from their medical records used in research, please include this information.

3. In your Data Availability statement, you have not specified where the minimal data set underlying the results described in your manuscript can be found. PLOS defines a study's minimal data set as the underlying data used to reach the conclusions drawn in the manuscript and any additional data required to replicate the reported study findings in their entirety. All PLOS journals require that the minimal data set be made fully available. For more information about our data policy, please see http://journals.plos.org/plosone/s/data-availability.

"Upon re-submitting your revised manuscript, please upload your study’s minimal underlying data set as either Supporting Information files or to a stable, public repository and include the relevant URLs, DOIs, or accession numbers within your revised cover letter. For a list of acceptable repositories, please see http://journals.plos.org/plosone/s/data-availability#loc-recommended-repositories. Any potentially identifying patient information must be fully anonymized.

Important: If there are ethical or legal restrictions to sharing your data publicly, please explain these restrictions in detail. Please see our guidelines for more information on what we consider unacceptable restrictions to publicly sharing data: http://journals.plos.org/plosone/s/data-availability#loc-unacceptable-data-access-restrictions. Note that it is not acceptable for the authors to be the sole named individuals responsible for ensuring data access.

We will update your Data Availability statement to reflect the information you provide in your cover letter.

4. PLOS requires an ORCID iD for the corresponding author in Editorial Manager on papers submitted after December 6th, 2016. Please ensure that you have an ORCID iD and that it is validated in Editorial Manager. To do this, go to ‘Update my Information’ (in the upper left-hand corner of the main menu), and click on the Fetch/Validate link next to the ORCID field. This will take you to the ORCID site and allow you to create a new iD or authenticate a pre-existing iD in Editorial Manager. Please see the following video for instructions on linking an ORCID iD to your Editorial Manager account: https://www.youtube.com/watch?v=_xcclfuvtxQ

5. Please amend either the title on the online submission form (via Edit Submission) or the title in the manuscript so that they are identical.

Additional Editor Comments:

This study investigating the association between the history of salpingectomy and the number of oocytes in women undergoing IVF has some issues that need to be addressed. Specifically, 2. the English needs a revision; 2. The authors should convince the reader that there were no selection biases; 3. Limits of the study needs to be discussed; 4. Several comparisons were performed. Please perform a Bonferroni correction. All the issues raised by the Reviewers should be carefully addressed.

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: No

Reviewer #2: Yes

3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: The authors investigated the association between the history of salpingectomy and the number of oocytes in young women undergoing IVF. They found that the number of retrieved oocytes was significantly lower in patients with a history of salpingectomy, and the influence was more evident in women with AMH<4.

The paper provides important data, but it still needs some revision to be acceptable for the PLOS ONE.

#1 It is unclear why the author investigated women under 35 years old. Ref No.13 showed no influence of salpingectomy on AFC in women under 35. Please clarify in the Introduction.

#2 A previous retrospective study (shown below) also showed the influence of salpingectomy on ovarian reserve in IVF-ET patients. The study showed a negative effect on AMH but no impact on retrieved oocytes. The number of retrieved oocytes was the primary outcome of the present study. Please discuss the impact on retrieved oocytes at great length in the Discussion.

1. Ye XP, Yang YZ, Sun XX. A retrospective analysis of the effect of salpingectomy on serum antiMullerian hormone level and ovarian reserve. American journal of obstetrics and gynecology. 2015;212(1):53 e1-10.

#3 In Table 2, the history of salpingectomy is not statistically significant in full model multivariate analysis. The author should explain this point.

#4 The author should explain the limitation of this study. The result was not conclusive. There are some limitations regarding retrospective design, sample size, or baseline difference between two groups. As mentioned in the Discussion, it is also possible that the baseline difference of AFC and AMH was not the result of salpingectomy but other pelvic conditions.

#5 In figure 2 and 3, p-values of Kruskal–Wallis tests are needed. The correction method should be shown to compare groups (e.g., Bonferroni correction).

#6 A significant figures of p-values are not the same. (Figure 1A p=0.006, Figure 2 and 3 p<0.05, and p<0.01 are used in tables)

#7 The author should decrease tone, especially in conclusion, because this study has several limitations.

Reviewer #2: Dear Authors,

The subject of the study is current. A clear, simple and understandable writing language was used in the article. I believe it will benefit the reader. This is a good study comparing the number of oocytes collected after salpingectomy. Congratulations to the authors.

Below are my recommendations for the study.

Best regards

- Some english grammar mistakes should be corrected.

-I suggest that some studies comparing the histopathological effects of salpingectomy and proximal tubal occlusion procedures on ovarian tissue should be given as examples [e.g. Atilgan R, Pala Ş, Kuloğlu T, Şanli C, Yavuzkir Ş, Özkan ZS. Comparison of the efficacy between bilateral proximal tubal occlusion and total salpingectomy on ovarian reserve and the cholinergic system: an experimental study. Turk J Med Sci. 2020 Jun 23;50(4):1097-1105. doi: 10.3906/sag-2002-179. ..................

Atilgan R, Kuloğlu T, Boztosun A, Orak U, Baspinar M, Can B, Sapmaz E. Investigation of the effects of unilateral total salpingectomy on ovarian proliferating cell nuclear antigen and follicular reserve: experimental study. Eur J Obstet Gynecol Reprod Biol. 2015 May;188:56-60. doi: 10.1016/j.ejogrb.2015.02.028.]

6. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #2: Yes: Remzi Atılgan

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

Submitted filename: review report.docx

Click here for additional data file.

18 Jan 2022

Comment Responses and Rebuttal

We greatly appreciated the editor and reviewers’ valuable comments. We have revised our manuscript accordingly and for adherence to the journal requirements. Our point-by-point responses to your comments are as follows.

# Additional Editor Comments

This study investigating the association between the history of salpingectomy and the number of oocytes in women undergoing IVF has some issues that need to be addressed. Specifically,

Comment 1. The English needs a revision.

Response 1: We apologize for the grammar mistakes in our manuscript. We have commissioned the help of an English-language editing team to revise our manuscript. We have attached the certificate for this service as a supplementary file.

Comment 2. The authors should convince the reader that there were no selection biases.

Response 2: In this study conducted from January 2012 through December 2019, all the women with infertility who met the inclusion and exclusion criteria of the study underwent oocyte retrieval at the Department of Obstetrics and Gynecology at Shin Kong Wu Huo Shih Hospital and were enrolled consecutively for analysis. The age-matched control subjects were enrolled by 3-year age strata, with the first names on the lists selected. No patients were excluded from final analysis as outliers. We have avoided selection bias as much as possible by employing these methods, which we have further detailed in the “Materials and methods” section.

Comment 3. Limits of the study needs to be discussed.

Response 3: This study has several limitations, including its retrospective design, small sample size, and lack of measurement before salpingectomy. In addition, because we only selected women without underlying tubal disease as our controls, those women with tubal disease but without tubal surgery history were not considered in this study. We have addressed these limitations in our revised manuscript in the revised “Discussion” section, page 19 and 20, lines 388–394.

Comment 4. Several comparisons were performed. Please perform a Bonferroni correction.

Response 4: Because the Bonferroni test is reportedly too stringent to identify the between-group differences with such a small sample size, we reanalyzed the data by applying nonparametric Kruskal–Wallis test, with Hochberg method for post hoc testing instead; we have described these procedures in our revised “Statistical Analysis” section and in the revised versions of Figs 2 and 3.

# Reviewer 1’ s comments:

The authors investigated the association between the history of salpingectomy and the number of oocytes in young women undergoing IVF. They found that the number of retrieved oocytes was significantly lower in patients with a history of salpingectomy, and the influence was more evident in women with AMH<4.

The paper provides important data, but it still needs some revision to be acceptable for the PLOS ONE.

Comment 1. It is unclear why the author investigated women under 35 years old. Ref No.13 showed no influence of salpingectomy on AFC in women under 35. Please clarify in the Introduction.

Response 1:

Thank you for your comments and suggestions. In the study of Chen et al. (i.e., Ref 13), a lower AFC was only discovered in women with infertility who were aged 35–39 years in response to salpingectomy and not in those women under the age of 35 years. This may imply an age-related ovarian function decline that highlights the negative effect of salpingectomy on ovarian reserves. However, Chen et al. did not perform subgroup analyses to investigate whether the effect of salpingectomy was also more pronounced in women aged under 35 years with suboptimal ovarian reserves. Moreover, in the study of Chen et al., the researchers selected patients with tubal disease as controls; the effect of salpingectomy may thus have been reduced, with underlying disease possibly acting as a confounding factor that reduced ovarian reserves. We have further clarified this matter in the revised “Introduction” on page 6, lines 124–131).

Comment 2. A previous retrospective study (shown below) also showed the influence of salpingectomy on ovarian reserve in IVF-ET patients. The study showed a negative effect on AMH but no impact on retrieved oocytes. The number of retrieved oocytes was the primary outcome of the present study. Please discuss the impact on retrieved oocytes at great length in the Discussion.

1. Ye XP, Yang YZ, Sun XX. A retrospective analysis of the effect of salpingectomy on serum anti-Mullerian hormone level and ovarian reserve. American journal of obstetrics and gynecology. 2015;212(1):53 e1-10.

Response 2:

We have cited the reference as [24] and discussed it in the “Discussion” section on pages 18 and 19, lines 364–376 in our revised manuscript as follows:

The primary outcome in our study was actual retrieved oocyte number. We contend that to obtain more embryos, using retrieved oocyte number as a reference would be superior to using circulating surrogate markers of ovarian reserve. The number of retrieved oocytes was also positively correlated with pregnancy outcome. The number of retrieved oocytes in relation to the total dose of ovarian stimulation drugs could reflect the ovarian response. However, a retrospective study [24] reported a negative effect of salpingectomy history on AMH levels but not on the retrieved oocyte number for women with infertility, which differs from our study results. Nevertheless, distinct from our study, short and minimal stimulation protocols were applied for controlled ovarian hyperstimulation in that retrospective study. In the present study, we solely used the GnRH antagonist protocol for controlled ovarian stimulation and adjusted the dosage to obtain the optimal response. Variations in stimulation protocol, total gonadotropin dosage, stimulation interval, baseline ovarian reserve, and (potentially) blood flow in the ovaries may have influenced the numbers of retrieved oocytes.

Comment 3. In Table 2, the history of salpingectomy is not statistically significant in full model multivariate analysis. The author should explain this point.

Response 3:

The univariate analysis indicated that factors such as salpingectomy history, AMH, and AFC were all significantly associated with the number of retrieved oocytes. However, because the AMH and AFC had more direct and stronger correlations with the retrieved oocyte number than did history of salpingectomy, the effect of salpingectomy history was no longer significant after applying the full model of multivariate analysis that included adjustment for AMH level and AFC. This has been described on page 13 of the revised manuscript, lines 235–241.

Comment 4. The author should explain the limitation of this study. The result was not conclusive. There are some limitations regarding retrospective design, sample size, or baseline difference between two groups. As mentioned in the Discussion, it is also possible that the baseline difference of AFC and AMH was not the result of salpingectomy but other pelvic conditions.

Response 4:

This study has several limitations, including the retrospective study design, small sample size, and lack of measurement before salpingectomy. In addition, because we only selected women without underlying tubal disease as controls, those women with tubal disease but without tubal surgery history were not considered in this study. We have addressed these limitations in our revised manuscript in the “Discussion” section, pages 19 and 20, lines 388–394.

Comment 5. In figure 2 and 3, p-values of Kruskal–Wallis tests are needed. The correction method should be shown to compare groups (e.g., Bonferroni correction).

Response 5:

In accordance with your suggestion, we have analyzed the data by applying a nonparametric Kruskal–Wallis test for the data in Figs 2 and 3. However, because the Bonferroni test is reportedly too stringent to identify the between-group differences with such a small sample size, we used the Hochberg correction method for post hoc testing instead. We have described these procedures in the revised “Statistical Analysis” section and illustrated the results in the revised Figs 2 and 3.

Comment 6. Significant figures of p-values are not the same. (Figure 1A p=0.006, Figure 2 and 3 p<0.05, and p<0.01 are used in tables).

Response 6:

We have amended all P-value notation in our revised manuscript in accordance with the conventional mode of representation. If P values are between .9 and .001, the actual number is presented. P values of >.9 or <.001 are presented as “>.9” or “<.001.”

Comment 7. The author should decrease tone, especially in conclusion, because this study has several limitations.

Response 7:

We have rewritten the conclusion (in the last paragraph of the “Discussion” section) in our revised manuscript. Rather than the original stronger recommendation, we have changed the sentence to suggest directing greater attention toward ovarian response in women who underwent IVF with infertility, without sufficient ovarian reserves, and with salpingectomy history.

# Reviewer 2’ s comments: Dear Authors,

The subject of the study is current. A clear, simple and understandable writing language was used in the article. I believe it will benefit the reader. This is a good study comparing the number of oocytes collected after salpingectomy. Congratulations to the authors.

Below are my recommendations for the study.

Best regards

Comment 1. Some English grammar mistakes should be corrected.

Response 1:

Thank you for your valuable comments and suggestions. We apologize for the sporadic grammar mistakes in our manuscript. We have revised our manuscript with the help of an English-language editing service and have attached the relevant certificate as a supplementary file.

Comment 2. I suggest that some studies comparing the histopathological effects of salpingectomy and proximal tubal occlusion procedures on ovarian tissue should be given as examples [e.g. Atilgan R, Pala Ş, Kuloğlu T, Şanli C, Yavuzkir Ş, Özkan ZS. Comparison of the efficacy between bilateral proximal tubal occlusion and total salpingectomy on ovarian reserve and the cholinergic system: an experimental study. Turk J Med Sci. 2020 Jun 23;50(4):1097-1105. doi: 10.3906/sag-2002-179. ..................

Atilgan R, Kuloğlu T, Boztosun A, Orak U, Baspinar M, Can B, Sapmaz E. Investigation of the effects of unilateral total salpingectomy on ovarian proliferating cell nuclear antigen and follicular reserve: experimental study. Eur J Obstet Gynecol Reprod Biol. 2015 May;188:56-60. doi: 10.1016/j.ejogrb.2015.02.028.]

Response 2:

We have cited these references as [18] and [19] and used the studies as examples in the “Introduction” section on page 6, lines 112–116 in our revised manuscript as follows:

An experimental study revealed that total salpingectomy in rats leads to more significant damage than proximal tubal occlusion in ovarian histopathology and the cholinergic system [18]. Another study also indicated that the unilateral total salpingectomy procedure can be detrimental to ipsilateral ovarian tissue as a result of ischemia–reperfusion injury [19].

Submitted filename: Response to Reviewers.docx

Click here for additional data file.

16 Feb 2022

A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.

A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.

An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols.

We look forward to receiving your revised manuscript.

Kind regards,

Paola Viganò

Academic Editor

PLOS ONE

Journal Requirements:

Additional Editor Comments:

Although the paper has been improved, there are still some problems that need to be addressed:

1. The Authors stated in their response ‘the effect of salpingectomy history was no longer significant after applying the full model of multivariate analysis that included adjustment for AMH level and AFC’ This is a strong message that should be clear in the Abstract.

2. The abstract needs to be improved as the message provided is misleading.

3. Figure legends are missing. How are data presented in the bars?

4. The choice of limits of AMH (4 ng/mL) and AFC (12) for the subgroup analysis needs to be justified.

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

Reviewer #2: All comments have been addressed

**********

2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: Thank you for your patient revision.

The manuscript has been revised well.

I think this manuscript will be acceptable for PLOS ONE.

Reviewer #2: The subject of the manuscript is current and I think it will be useful to the reader. The authors made the necessary corrections in line with the suggestions. I think the article can be published in its current form. Congratulations to the authors.

**********

7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: Yes: Tsutomu IDA

Reviewer #2: Yes: Remzi Atılgan

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

11 Apr 2022

Dear Academic editor:

We greatly appreciated the valuable comments for improving our study. We have revised our manuscript accordingly and for adherence to the journal requirements. Our point-by-point responses to your comments are as follows.

# Academic Editor Comments

Although the paper has been improved, there are still some problems that need to be addressed:

Comment 1. The Authors stated in their response ‘the effect of salpingectomy history was no longer significant after applying the full model of multivariate analysis that included adjustment for AMH level and AFC’ This is a strong message that should be clear in the Abstract.

Response 1: Indeed, this message should be clear, and we have added in the Abstract, subtitled “measurements and main results”, line 64-69. Also, we have modified the context of the “conclusion” section in the Abstract with highlighting the message as stated above.

The problem that univariate regression analysis in our study indicated that factors such as salpingectomy history, AMH, and AFC were all significantly associated with the number of retrieved oocytes. However, in the multivariate-adjusted complete model, only AFC and AMH levels continued to exhibit significant associations with the number of retrieved oocytes. The explanation is that the effect of previous salpingectomy toward ovarian response are not as direct as ovarian surrogate biomarkers, which had been collected just around the time of controlled ovarian stimulation and transvaginal oocytes retrieval.

Salpingectomy impaired the circulation of ovary and may cause ischemic-reperfusion injury, and indirectly affect the ovarian function and response to fertility drugs afterwards. Therefore, in the full model of multivariate analysis, we can see that AFC and AMH have more direct influences toward number of retrieved oocytes than other factors.

Comment 2. The abstract needs to be improved as the message provided is misleading.

Response 2: Thank you for the comments and suggestions. We have added the important message of our statistical results in the Abstract, subtitled” measurements and main results” and “conclusion”. Although the full mode of multivariate analysis did not reveal the negative impact of previous salpingectomy on the number of retrieved oocytes, the detrimental effect to the ovarian function and response still presented via the decreased ovarian surrogate markers (AFC and AMH). Therefore, infertile patients with previous salpingectomies and suboptimal ovarian reserve should be paid attention to their ovarian response, however, postsurgical AMH and AFC levels still possess a more direct predictive value on ovarian response than the history of salpingectomy.

Comment 3. Figure legends are missing. How are data presented in the bars?

Response 3: We do apologize for the mistakes of incomplete figure legends. According to the policy of PLOS ONE journal for figure legends, we inserted the figure legends (including Fig. 1 to 3) by the way of inlay in the Manuscript, page 14 and 16. The data in the bars, including the values of means, standard deviations, were provided in the minimal data set of supplementary files. P values presented as an actual number in the figure above the bar plot when there was a significant difference.

Comment 4. The choice of limits of AMH (4 ng/mL) and AFC (12) for the subgroup analysis needs to be justified.

Response 4: In the full mode of multivariate analysis within our study, we found that AMH and AFC continued to be significantly associated with the number of retrieved oocytes. We further divided the subgroups with different level of surrogate ovarian biomarkers to realize the impact on ovarian response.

The cutoff value for AMH (4 ng/mL) was based on the reported 75th percentile of AMH levels of generally healthy Chinese women aged 35 years by the reference [21], BJOG 2020;127(6):720-8. The 75th percentile of AMH levels between 35 to 36 year-old chinese women lies between 4.229 to 3.973 ng/mL, which can be found in the Table 1 of the reference. Another reason for the cutoff value is because the limited case number in our study, we chose accordingly rather than calculated median AMH of our study. The cutoff value for AFC (12 follicles) was based on the calculated median AFC of all enrolled patients in our study. Above description was written in the Materials and Methods, section “Controlled ovarian stimulation and outcome measures” last two sentences.

The reason we used subgroup analysis to distinguish the patients with optimal ovarian reserve, which can be normal or hyper-responders and often with plenty number of retrieved oocytes and could mask the effect of history of salpingectomy.

Submitted filename: Response to Reviewers.docx

Click here for additional data file.

21 Apr 2022

Prior salpingectomy impairs the retrieved oocyte number in in vitro fertilization cycles of women under 35 years old without optimal ovarian reserve

PONE-D-21-34495R2

Dear Dr. Chen,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org.

If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org.

Kind regards,

Paola Viganò

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments:

25 Apr 2022

PONE-D-21-34495R2

Prior salpingectomy impairs the retrieved oocyte number in in vitro fertilization cycles of women under 35 years old without optimal ovarian reserve

Dear Dr. Chen:

I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department.

If your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org.

If we can help with anything else, please email us at plosone@plos.org.

Thank you for submitting your work to PLOS ONE and supporting open access.

Kind regards,

PLOS ONE Editorial Office Staff

on behalf of

Dr. Paola Viganò

Academic Editor

PLOS ONE