Neonatal outcome in 29 pregnant women with COVID-19: A retrospective study in Wuhan, China.

BACKGROUND: As of June 1, 2020, coronavirus disease 2019 (COVID-19) has caused more than 6,000,000 infected persons and 360,000 deaths globally. Previous studies revealed pregnant women with COVID-19 had similar clinical manifestations to nonpregnant women. However, little is known about the outcome of neonates born to infected women. METHODS AND
FINDINGS: In this retrospective study, we studied 29 pregnant women with COVID-19 infection delivered in 2 designated general hospitals in Wuhan, China between January 30 and March 10, 2020, and 30 neonates (1 set of twins). Maternal demographic characteristics, delivery course, symptoms, and laboratory tests from hospital records were extracted. Neonates were hospitalized if they had symptoms (5 cases) or their guardians agreed to a hospitalized quarantine (13 cases), whereas symptom-free neonates also could be discharged after birth and followed up through telephone (12 cases). For hospitalized neonates, laboratory test results and chest X-ray or computed tomography (CT) were extracted from hospital records. The presence of antibody of SARS-CoV-2 was assessed in the serum of 4 neonates. Among 29 pregnant COVID-19-infected women (13 confirmed and 16 clinical diagnosed), the majority had higher education (56.6%), half were employed (51.7%), and their mean age was 29 years. Fourteen women experienced mild symptoms including fever (8), cough (9), shortness of breath (3), diarrhea (2), vomiting (1), and 15 were symptom-free. Eleven of 29 women had pregnancy complications, and 27 elected to have a cesarean section delivery. Of 30 neonates, 18 were admitted to Wuhan Children's Hospital for quarantine and care, whereas the other 12 neonates discharged after birth without any symptoms and had normal follow-up. Five hospitalized neonates were diagnosed as COVID-19 infection (2 confirmed and 3 suspected). In addition, 12 of 13 other hospitalized neonates presented with radiological features for pneumonia through X-ray or CT screening, 1 with occasional cough and the others without associated symptoms. SARS-CoV-2 specific serum immunoglobulin M (IgM) and immunoglobulin G (IgG) were measured in 4 neonates and 2 were positive. The limited sample size limited statistical comparison between groups.
CONCLUSIONS: In this study, we observed COVID-19 or radiological features of pneumonia in some, but not all, neonates born to women with COVID-19 infection. These findings suggest that intrauterine or intrapartum transmission is possible and warrants clinical caution and further investigation. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR2000031954 (Maternal and Perinatal Outcomes of Women with coronavirus disease 2019 (COVID-19): a multicenter retrospective cohort study).

Introduction

Since December 2019, a novel coronavirus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread through human-to-human transmission across China [1] and now internationally to over 160 countries. The World Health Organization initially classified the outbreak of the coronavirus disease 2019 (COVID-19) as a Public Health Emergency of International Concern (PHEIC), and on March 11, 2020, they upgraded it to a pandemic [2]. According to the Chinese Center for Disease Control and Prevention (China CDC), 25.1% of the 44,672 confirmed cases in mainland China were women of reproductive age [3,4]. Pregnant women experience immunologic and physiologic changes, which make them potentially more susceptible to viral respiratory infections, including respiratory syncytial virus, influenza virus, and SARS-CoV [5]. There is growing evidence that COVID-19 infections in pregnant women are not more severe than in age-matched women where symptoms are typically mild [6-12], and childbirth did not aggravate the course of the illness or chest computed tomography (CT) features of COVID-19 [13]. In addition, previous research suggests infants under 1 year old are susceptible to COVID-19 when in contact with infected family members [14]. However, for neonates born to infected women, little is known about their susceptibility.

In this retrospective study, we analyzed maternal and neonatal clinical characteristics of all women with confirmed or clinical diagnosed COVID-19 infection who gave birth in 2 of the 5 general hospitals in Wuhan, China and followed up their neonates through telephone interview or collecting their clinical data in the only designated children’s hospital to assess neonatal outcomes associated with maternal COVID-19 infection.

Methods

Study design and participants

All pregnant women diagnosed with COVID-19 who gave birth between January 30 to March 10, 2020 in 2 designated general hospitals in Wuhan, China (Renmin Hospital, Wuhan University, and Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology) were included in this retrospective study. Clinical characteristics, examination results, and treatment course were extracted from their medical records.

All procedures performed in this study involving human participants were in accordance with the ethical standards of the Medical Ethical Committee of Wuhan Children’s Hospital (Wuhan Maternal and Child Healthcare Hospital), Tongji Medical College, Huazhong University of Science and Technology (WHCH2020014), Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology (2020–28), and Renmin Hospital, Wuhan University (WDRY2020-K097). For this retrospective study in clinical practice, the requirement for written informed consent was waived by the ethics committee.

Maternal data

We followed the diagnostic criteria for COVID-19 in pregnant women according to the New Coronavirus Pneumonia Prevention and Control Program (fifth, sixth, and seventh edition) [15-17] published by the National Health Commission of China (specific diagnostic criteria were shown in S1 Text). In women where a PCR-kit for SARS-CoV-2 RNA was not available, the diagnosis was made with chest CT scan.

For mothers, we collected sociodemographic data (maternal age, body mass index [BMI], educational attainment [>high school or not], and occupation [employed specifically at a hospital, employed but not at a hospital, or unemployed]), maternal parity (primiparous or multiparous), medical history records (fever, cough, shortness of breath, diarrhea, and vomiting), laboratory tests, chest CT images, throat swab tests, use of mechanical ventilation, and intensive care unit [ICU] admission. Laboratory tests included routine antenatal blood tests (white blood cell count [WBC], lymphocyte count [LYM], lymphocyte percentage [LYM%]), levels of C-reactive protein (CRP) in serum, biochemical indicators of hepatic and renal function (aspartate transaminase [AST], alanine aminotransferase [ALT], creatine kinase [CK], lactate dehydrogenase [LDH], total protein [TP], albumin [ALB], uric acid [UA], creatinine [CREA], and urea nitrogen [BUN]), and postnatal blood routine tests and levels of CRP. For all women, we registered pregnancy outcomes, i.e., gestational age at delivery, mode of delivery, and occurrence of gestational hypertensive disorder, gestational diabetes mellitus, premature rupture of membranes, and fetal distress.

Neonatal data

Neonates who need hospital care or who were admitted on parental request for quarantined observation were admitted to a designated children’s hospital (Wuhan Children’s Hospital [Wuhan Maternal and Child Healthcare Hospital], Tongji Medical College, Huazhong University of Science and Technology). When parents did not opt for quarantined observation, neonates were discharged after birth. For these neonates, the outcome was obtained through parental telephone interview.

Neonatal data collected included sex, birthweight, 1- and 5-minute Apgar scores, congenital anomalies, fever, respiratory distress and neonatal ICU (NICU) admission. Neonates admitted at NICU care had additional data collected including throat swabs, anal swabs, as well as chest X-rays or CT images. Laboratory data collected included routine blood tests (WBC, LYM, LYM%, neutrophil count [NEU], neutrophil percentage [NEU%], platelet count [PLT]), levels of CRP, procalcitonin (PCT) in serum, and biochemical indicators of hepatic and renal function (AST, ALT, CK, LDH, TP, ALB, UA, CREA, and BUN). In addition, according to the New Coronavirus Pneumonia Prevention and Control Program (seventh edition) [17], SARS-CoV-2 specific immunoglobulin M (IgM) and immunoglobulin G (IgG) was examined in 4 neonates’ serum. The diagnosis of pneumonia in neonates was based on risk factors, clinical manifestations, radiological findings, and laboratory tests [18]. The diagnosis of COVID-19 in neonates was according to an experts′ consensus statement [19] (specific diagnostic criteria are shown in S1 Text).

SARS-CoV-2 testing

Maternal and neonatal throat swabs and neonatal anal swabs were collected and tested for SARS-CoV-2 RNA using quantitative real time-PCR (qRT-PCR) technology and hydrolysis probe technology (the New Coronavirus 2019 Nucleic Acid Detection Kit [Dual Fluorescence PCR] provided by Shuo Shi Biotechnology Co., Ltd, Jiangsu, China). SARS-CoV-2 specific IgM and IgG were detected using New Coronavirus 2019-nCoV IgG Antibody Detection Kit (Chemiluminescence) (Yahuilong Biological Technology Co., Ltd. Shenzhen, China) [20-22]. Sample collection, processing, and laboratory testing followed guidance from the World Health Organization [23].

Statistical analysis

All analyses were performed using SAS 9.3 (SAS Institute, Inc, North Carolina, USA, https://www.sas.com/zh_cn/software/university-edition/download-software.html#windows). Continuous variables were described as mean (standard deviation [SD]) or median (interquartile range [IQR]). Categorical variables were represented as frequencies with proportions. All the research data were available at the ResMen Manager of Chinese Clinical Trial Registry (www.medresman.org), and the registration number is ChiCTR2000031954.

Results

The flow chart of the study participants was shown in Fig 1. We studied 29 women with a COVID-19 infection, of which 13 were diagnosed with a SARS-CoV-2 RNA test using qRT-PCR on samples from the respiratory tract, and 16 were clinically diagnosed based on chest CT images, as there were not enough PCR kits available. Among 29 pregnant COVID-19-infected women, 14 experienced mild symptoms including fever (8), cough (9), shortness of breath (3), diarrhea (2), vomiting (1), whereas 15 women had no symptoms. All chest CT images showed typical signs of COVID-19 pneumonia. In the 14 women with symptoms, 9 were SARS-CoV-2 RNA positive, while in the 15 symptom-free women with abnormal chest CT images, 6 were SARS-CoV-2 RNA positive. None of the women required mechanical ventilation or were admitted to the ICU.

Fig 1

Flow chart of participants inclusion.

Of the 30 neonates born (including 1 set of twins), 18 were admitted to the Children’s Hospital to have further examination (5 with symptoms and 13 just for quarantine). The other 12 neonates discharged immediately did not undergo imaging screening, and follow-up showed no symptoms or abnormal findings. Among 18 neonates admitted to hospital, 17 neonates had pneumonia-like imaging changes. Five neonates were diagnosed with a COVID-19 infection, including 2 confirmed and 3 suspected. COVID-19, coronavirus disease 2019.

The distribution of the demographic characteristics, antenatal clinical conditions, and laboratory tests of women is shown in Table 1. The pregnancy-related complications, mode of delivery, postpartum conditions, and laboratory tests of the mothers are shown in Table 2. Among 29 pregnant women, 11 had complications during pregnancy, including gestational hypertensive disorder (2), gestational diabetes mellitus (3), gestational anemia (3), premature rupture of membrane (5), fetal distress (3), intrahepatic cholestasis of pregnancy (1), hepatitis (1), thrombocytopenia (1), coagulopathy (2), hypothyroidism (1), and hepatitis B virus (HBV) infection (1). Although the majority of women had a cesarean section (CS) delivery for nonmedical reasons, 2 women elected to have a vaginal delivery, and both their neonates had radiological changes for pneumonia but without clinical pneumonia. There was only 1 set of twins in this study, and both neonates had a pneumonia-like lung image.

Table 1

Demographic characteristics, prepartum conditions and laboratory tests of mothers infected with COVID-19.

	All mothers	Mothers whose child had COVID-19	Mothers whose child had abnormal radiological findings without COVID-19	Mothers whose child discharged after birth
	(n = 29)	(n = 5)	(n = 12)	(n = 12)
	No. (%)	No. (%)	No. (%)	No. (%)
Age, mean (SD), year	29.59 (3.56)	29.40 (3.65)	29.33 (4.01)	29.92 (3.34)
BMI, mean (SD), kg/m2	24.10 (5.54)	21.94 (6.10)	23.65 (5.43)	25.45 (5.54)
Educational attainment
College or above	17 (58.62)	1 (20.00)	9 (75.00)	7 (58.33)
High school or lower	12 (41.38)	4 (80.00)	3 (25.00)	5 (41.67)
Occupation
Employed but not at a hospital	11 (37.93)	2 (40.00)	6 (50.00)	3 (25.00)
Employed specifically at a hospital	4 (13.79)	0 (0.00)	2 (16.67)	2 (16.67)
Unemployed	14 (48.28)	3 (60.00)	4 (33.33)	7 (58.33)
Parity
Primiparous	24 (82.76)	5 (100.00)	10 (83.33)	9 (75.00)
Multiparous	5 (17.24)	0 (0.00)	2 (16.67)	3 (25.00)
First signs and symptoms
Fever	8 (27.59)	2 (40.00)	4 (33.33)	2 (16.67)
Cough	9 (31.03)	2 (40.00)	4 (33.33)	3 (25.00)
Shortness of breath	3 (10.34)	1 (20.00)	1 (8.33)	1 (8.33)
Diarrhea	2 (6.90)	0 (0.00)	1 (8.33)	1 (8.33)
Vomiting	1 (3.45)	1 (20.00)	0 (0.00)	0 (0.00)
None	15 (51.72)	2 (40.00)	6 (50.00)	7 (58.33)
Throat swab	13 (44.83)	3 (60.00)	8 (66.67)	2 (16.67)
Chest CT	29 (100.00)	5 (100.00)	12 (100.00)	12 (100.00)
Prepartum laboratory tests
White blood cell count, median (IQR), ×109/L	8.03 (4.50)	8.03 (1.58)	9.90 (5.89)	7.30 (3.32)
<3.5	0 (0.00)	0 (0.00)	0 (0.00)	0 (0.00)
3.5–9.5	19 (65.52)	4 (80.00)	6 (50.00)	9 (75.00)
>9.5	10 (34.48)	1 (20.00)	6 (50.00)	3 (25.00)
Lymphocyte count, median (IQR), ×109/L	1.19 (0.48)	1.32 (0.41)	1.17 (0.59)	1.22 (0.35)
<1.1	9 (31.03)	2 (40.00)	4 (33.33)	3 (25.00)
1.1–3.2	20 (68.97)	3 (60.00)	8 (66.67)	9 (75.00)
>3.2	0 (0.00)	0 (0.00)	0 (0.00)	0 (0.00)
Lymphocyte percentage, median (IQR), %	14.25 (6.37)	16.70 (4.80)	13.00 (3.55)	15.05 (6.95)
C-reactive protein, median (IQR), mg/L	3.50 (16.65)	18.65 (15.12)	12.20 (26.85)	1.00 (3.50)
Aspartate transaminase, median (IQR), U/L	15.60 (11.00)	16.00 (24.50)	15.30 (4.12)	15.10 (11.75)
Alanine aminotransferase, median (IQR), U/L	16.00 (13.60)	25.00 (20.30)	17.50 (12.68)	14.50 (6.95)
Creatine kinase, median (IQR), U/L	60.50 (48.50)	28.00 (12.00)	69.00 (53.00)	69.50 (49.50)
Lactate dehydrogenase, median (IQR), U/L	195.50 (53.50)	201.00 (21.00)	202.00 (92.00)	178.50 (44.20)
Total protein, median (IQR), g/L	59.60 (6.65)	56.10 (2.70)	62.20 (9.40)	60.80 (5.67)
Albumin, median (IQR), g/L	36.00 (4.65)	36.30 (5.70)	35.20 (4.68)	36.20 (4.40)
Uric acid, median (IQR), μmol/L	296.00 (102.50)	276.00 (69.00)	295.00 (119.70)	308.00 (109.20)
Creatinine, median (IQR), μmol/L	44.00 (9.20)	44.80 (11.10)	44.50 (10.23)	43.75 (6.75)
Urea nitrogen, median (IQR), mmol/L	2.64 (0.65)	2.16 (0.76)	2.42 (0.53)	2.70 (0.17)

Data are presented as the mean (SD), median (IQR), or frequency (proportion). SI conversion factors: To convert aspartate transaminase, alanine aminotransferase, creatine kinase, and lactate dehydrogenase to μkat/L, multiply values by 0.0167.

BMI, body mass index; COVID-19, coronavirus disease 2019; CT, computed tomography.

Table 2

Pregnancy-related complications, postpartum conditions, and laboratory tests of mothers infected with COVID-19.

	All mothers	Mothers whose child had COVID-19	Mothers whose child had abnormal radiological findings without COVID-19	Mothers whose child discharged after birth
	(n = 29)	(n = 5)	(n = 12)	(n = 12)
	No. (%)	No. (%)	No. (%)	No. (%)
Pregnancy-related complications
Gestational hypertensive disorder	2 (6.90)	0 (0.00)	0 (0.00)	2 (16.67)
Gestational diabetes mellitus	3 (10.34)	1 (20.00)	0 (0.00)	2 (16.67)
Gestational anemia	3 (10.34)	2 (40.00)	1 (8.33)	0 (0.00)
Preterm premature rupture of membranes	5 (17.24)	0 (0.00)	1 (8.33)	4 (33.33)
Fetal distress	3 (10.34)	0 (0.00)	3 (25.00)	0 (0.00)
Postpartum hemorrhage	0 (0.00)	0 (0.00)	0 (0.00)	0 (0.00)
Other complications	5 (17.24)	2 (40.00)	1 (8.33)	2 (16.67)
Mode of delivery
Vaginal	2 (6.90)	0 (0.00)	2 (16.67)	0 (0.00)
Cesarean section	27 (93.10)	5 (100.00)	10 (83.33)	12 (100.00)
Number of fetus
Singleton	28 (96.55)	5 (100.00)	11 (91.67)	12 (100.00)
Twin	1 (3.45)	0 (0.00)	1 (8.33)	0 (0.00)
Gestational age at delivery, weeks
35–36	3 (10.34)	0 (0.00)	2 (16.67)	1 (8.33)
37–38	14 (48.28)	3 (60.00)	7 (58.33)	4 (33.33)
39–41	12 (41.38)	2 (40.00)	3 (25.00)	7 (58.33)
White blood cell count, median (IQR), ×109/L	8.68 (3.32)	7.63 (3.35)	8.47 (4.96)	9.14 (2.28)
Lymphocyte count, median (IQR), ×109/L	1.35 (0.69)	1.31 (0.76)	1.38 (0.57)	1.24 (0.60)
Lymphocyte percentage, median (IQR), %	15.35 (10.22)	16.65 (11.02)	15.65 (11.91)	15.05 (7.39)
C-reactive protein, median (IQR), mg/L	22.20 (36.39)	52.00 (78.83)	16.00 (32.00)	24.70 (28.99)

Data are presented as the median (IQR) or frequency (proportion).

COVID-19, coronavirus disease 2019.

Five neonates were diagnosed as having COVID-19 infection, and all were female. The clinical features of these neonates and their mothers are presented in Tables 3 and 4. Brief histories of the 5 COVID-19-infected neonates are detailed in the supporting information (S2 Text). The date of birth was defined as Day 1. Based on the typical findings in CT images (Fig 2) and positive SARS-CoV-2 RNA test in throat swab samples, Patient 5 and Patient 9 were diagnosed as confirmed COVID-19 infection. Although SARS-CoV-2 specific serum IgM and IgG were positive in Patient 10 and Patient 18, repeated throat swab tests were all negative. Combined with the radiological features of viral pneumonia, Patient 10 and Patient 18 were diagnosed as suspected COVID-19 infection. Because of the characteristic COVID-19 pneumonia manifestations of both lungs (ground-glass opacity [GGO] in bilateral peripheral lungs, Fig 2), Patient 12 was also diagnosed as suspected COVID-19 infection.

Table 3

Clinical features of mothers whose neonates was infected with COVID-19.

Patient	5	9	10	12	18
Symptoms	Cough	No	No	Fever, cough, vomiting	Fever, stuffy nose, shortness of breath
Chest CT	Patchy GGO in right lung, especially in right lower lobe	Bilateral focal GGO	Left lung infectious lesions, bilateral pleural thickening, little pleural effusion	Bilateral multiple GGO	Bilateral scattered GGO
Throat swab	(–)	(–)	(+)	(+)	(+) (+)
SARS-CoV-2 IgM, AU/mL	NA	NA	NA	NA	279.72, Day -1; 112.66, Day 8
SARS-CoV-2 IgG, AU/mL	NA	NA	NA	NA	107.89, Day -1; 116.30, Day 8
White blood cell count, ×109/L	8.19	13.7	4.69	6.61	8.03
Lymphocyte count, ×109/L	1.49	1.32	0.78	1.58	1.08
Lymphocyte percentage, %	18.2	9.6	16.7	23.9	13.4
C-reactive protein, mg/L	20.4	16.9	NA	7	57
Aspartate transaminase, U/L	16	10	15.5	56	40
Alanine aminotransferase, U/L	25	14	17.7	54.7	38
Creatine kinase, U/L	28	56	35	23	17
Lactate dehydrogenase, U/L	201	216	117	195	222
Total protein, g/L	56.9	62.4	56.1	50.8	54.2
Albumin, g/L	36.3	38.8	31.5	26.5	37.2
Uric acid, μmol/L	339	456	276	270	259
Creatinine, μmol/L	51	45	44.8	33.9	28
Urea nitrogen, mmol/L	NA	NA	1.4	2.91	NA
Treatment	Oseltamivir, Methylprednisolone, Peramivir	No	Ribavirin, Abidol	Ribavirin, Nifedipine, Clindamycin, Heparin	Oseltamivir, Methylprednisolone, Abidol, Ribavirin
Pregnant-related complications	No	GDM	ICP, anemia, HBV infection	Anemia	Thrombocytopenia
Mode of delivery	CS	CS	CS	CS	CS
COVID-19 diagnosis	Clinical diagnosed	Clinical diagnosed	Confirmed	Confirmed	Confirmed

SI conversion factors: To convert aspartate transaminase, alanine aminotransferase, creatine kinase, and lactate dehydrogenase to μkat/L, multiply values by 0.0167.

COVID-19, coronavirus disease 2019; CS, cesarean section; CT, computed tomography. GDM, gestational diabetes mellitus; GGO, ground-glass opacity; HBV, hepatitis B virus; ICP, intrahepatic cholestasis of pregnancy; IgG, immunoglobulin G; IgM, immunoglobulin M; NA, not available; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.

Table 4

Clinical features of 5 neonates with COVID-19.

Patient	5	9	10	12	18
Days from mother diagnosed, days	0	0	0	14	10
Sex	Female	Female	Female	Female	Female
Gestational age, weeks	40+4	39+1	38+3	37+1	37+6
Birthweight, g	3,360	3,570	2,760	2,940	3,120
AGA	AGA	AGA	AGA	AGA	AGA
Apgar score at 1 minute	9	9	10	10	9
Apgar score at 5 minutes	10	10	10	10	10
Congenital anomaly	No	No	No	ASD	No
Symptoms	No	37.5°C, Day 3	No	No	No
Throat swab	(–) (+) (–) (–)	(+?) (–) (+) (–) (–) (–)	(–) (–) (–)	(–) (–) (–)	(–) (–) (–) (–)
Anal swab	(–)	(–)	(–)	(–)	(–)
Chest X-ray or CT after birth, Fig 2	GGO	GGO	GGO	GGO	GGO
White blood cell count, ×109/L	19.23	14.27	16.59	18.79	19.29
Lymphocyte count, ×109/L	2.61	2.19	2.45	2.95	4.3
Lymphocyte percentage, %	13.6	15.3	14.8	15.7	22.3
C-reactive protein, mg/L	<0.75	11.4	<0.75	1.09	<0.79
Procalcitonin, ng/mL	(–)	2.95	NA	NA	NA
SARS-CoV-2 IgM, AU/mL	NA	0.46, Day 26	10.65, Day 28	NA	45.83, Day 1; 11.75, Day 15
SARS-CoV-2 IgG, AU/mL	NA	2.36, Day 26	80.46, Day 28	NA	140.32, Day 1; 69.94, Day 15
Treatment	Symptomatic treatment	Interferon inhalation, Amoxicillin-Clavulanate potassium	Symptomatic treatment	Interferon inhalation	Interferon inhalation
NICU stay, days	14	16	29	10	23
Hospitalization stay, days	15	16	29	16	23
X-ray or CT before discharge, Fig 2	No abnormal findings	No abnormal findings	No abnormal findings	Partial absorption of pneumonia	Increased densities with interlobular septal thickening
COVID-19 diagnosis	Confirmed	Confirmed	Suspected	Suspected	Suspected

AGA, appropriate for gestational age; ASD, atrial septal defect; COVID-19, coronavirus disease 2019; CT, computed tomography; GGO, ground-glass opacity; IgG, immunoglobulin G; IgM, immunoglobulin M; NA, not available; NICU, neonatal intensive care unit; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.

Fig 2

Chest X-ray or CT (transverse plane) images of 5 neonates diagnosed with COVID-19 infection (2 confirmed, 3 suspected) after birth, in the treatment, and before discharge.

(A-B, Patient 5) Chest CT images (A) obtained after birth showed peripheral GGOs in the posterior basal segment of left lung lower lobe. Chest X-ray film (B) before discharge showed no abnormal findings. (C-E, Patient 9) Chest CT images (C) showed diffuse GGO with multifocal consolidations in the peripheral regions of bilateral lungs. Chest X-ray film (D) in treatment showed patchy obscure shadows in bilateral lung lower fields. Chest X-ray film (E) before discharge showed complete disappearance of pneumonia. (F-H, Patient 10) Chest CT images (F) obtained after birth showed patchy GGO in the posterior basal segment of right lower lobe and large GGO in the posterior basal segment of left lower lobe. Chest X-ray film (G) in treatment showed significant release of pneumonia. Chest X-ray film (H) before discharge showed nothing abnormal findings except mild increased lung markings. (I-J, Patient 12) Chest CT images (I) obtained after birth showed peripheral focal consolidations in the posterior basal segments of bilateral lower lobes and multiple patchy GGO bilaterally. Chest X-ray film (J) showed partial absorption of pneumonia. (K-M, Patient 18) Chest CT images (K) obtained after birth showed reduced latency with GGO in bilateral lower lobes. Chest X-ray film (L) in treatment showed increased bilateral lung markings. Chest X-ray film (M) before discharge showed increased densities of previous existing pulmonary lesions with interlobular septal thickening. All images have been de-identified to protect patient privacy. COVID-19, coronavirus disease 2019; CT, computed tomography; GGO, ground-glass opacity.

The characteristics of the 18 hospitalized neonates are shown in Tables 4 and 5, S1 Table, Fig 2, S1 and S2 Figs. All 18 neonates had a chest X-ray or CT image within 3 days of delivery with abnormal radiological findings. The typical pneumonia-like findings were found in the 5 neonates with COVID-19 and 12 other neonates (7 female and 5 male), including diffuse or scattered patchy obscure shadows of unilateral or bilateral lungs, partial GGO, and multifocal consolidations, mostly in the lower lobes (Fig 2 and S1 Fig). The other male neonate with mild birth asphyxia showed increased lung markings and was later diagnosed with hypoxic-ischemic encephalopathy (HIE) (Patient 11).

Table 5

Characteristics of hospitalized neonates without COVID-19.

Patient	1	2	3	4	6	7	8	11	13	14	15	16	17
Days from mother diagnosed, days	7	7	1	-2	-2	0	0	-2	-1	1	0	0	0
Sex	Female	Female	Female	Female	Male	Female	Male	Male	Male	Male	Female	Female	Male
Gestational age, weeks	37+1	37+6	35+6	35+5	39+5	39+4	39+0	38+4	37+2	40+1	37+2	37+2	38+1
Birthweight, g	2,890	3,400	2,830	2,300	3,450	2,650	3,000	2,650	2,900	3,830	2,350	2,620	2,930
AGA	AGA	AGA	AGA	AGA	AGA	SGA	AGA	SGA	AGA	AGA	SGA	AGA	AGA
Apgar score at 1 minute	9	9	9	9	9	9	9	7	10	10	10	10	10
Apgar score at 5 minutes	10	10	10	10	10	10	9	9	10	10	10	10	10
Congenital anomaly	No	No	No	No	No	No	PDA	No	No	No	No	No	PDA
Fever	No	No	No	No	No	No	No	No	No	No	No	No	No
Other symptoms	Occasional cough	NEC (bloody stools, Day 4)	No	No	No	No	No	Mild birth asphyxia	No	NEC (bloody stools, Day 4)	NEC (repeated vomiting and bloating, Day 2)	No	No
Throat swab	(–)	(–)	(–)	(–)	(–)	(–)	(–)	(–)	(–)	(–)	(–)	(–)	(–)
Anal swab	(–)	(–)	(–)	(–)	(–)	(–)	(–)	(–)	(–)	(–)	(–)	(–)	(–)
Chest X-ray or CT after birth	Patchy obscure shadow in the left lower lung field	Scattered patchy shadows in bilateral lung fields	Scattered patchy shadows in bilateral lung fields	Scattered patchy shadows in bilateral lung fields	Focal patchy consolidation is infiltrated around the left lower bronchial and paramediastinal emphysema	Scattered patchy shadows in bilateral lung fields	Focal GGO located in the medial basal segment of right lower lobe	Increased bilateral lung markings	Multifocal patchy GGOs bilaterally and focal consolidation located in the medial basal segment of right lower lobe	Pneumonia, bilateral thickened interlobular fissure	Decreasing changes of pulmonary lucency presenting as GGO in bilateral lower lobes and focal consolidation around the left lower bronchial	Multifocal consolidations located in the peripheral region of bilateral lower lobes	Diffuse GGO with multifocal consolidations located in bilateral lower lobes
Treatment	Sulbactam-Cefoperazone	Meropenem (for NEC)	Symptomatic treatment	Symptomatic treatment	Ceftazidime	Amoxicillin-Clavulanate potassium	Interferon inhalation	Amoxicillin-Clavulanate potassium	Interferon inhalation	Ceftazidime	Interferon inhalation, Ceftazidime, NEC treatment	Interferon inhalation, Ceftazidime	Interferon inhalation, Amoxicillin-Clavulanate potassium
NICU stay, days	11	14	11	13	11	7	11	8	15	16	30	14	15
Hospitalization stay, days	11	17	11	28	14	7	14	26	15	16	30	14	15
X-ray or CT before discharge	No abnormalities	Slightly increasing lung markings	Slightly increasing lung markings	Slightly increasing lung markings	No abnormalities	Slightly increasing lung markings	No abnormalities	Increased bilateral lung markings (Day 41)	No abnormalities	No abnormalities	Scattered patchy blurry shadows	No abnormalities	Pulmonary lesions are almost resolved
Discharge diagnosis	Hyperbilirubinemia	NEC	Hyperbilirubinemia	Premature infant	Hyperbilirubinemia	Myocardial damage	PDA	HIE	Hyperbilirubinemia	NEC	NEC	Hyperbilirubinemia	PDA

(–), negative; (+), positive; those who tested negative for multiple times also showed (–).

AGA, appropriate for gestational age; COVID-19, coronavirus disease 2019; CT, computed tomography; GGO, ground-glass opacity; HIE, hypoxic-ischemic encephalopathy; NEC, neonatal necrotizing enterocolitis; PDA, patent ductus arteriosus; SGA, small for gestational age.

All 18 hospitalized neonates were admitted to the NICU for care (Table 5), and laboratory tests were performed (see S1 Table for age specific results). Three neonates were born with congenital heart disease (patent ductus arteriosus [PDA] and atrial septal defect [ASD]), and they all had radiological features for pneumonia. One neonate with COVID-19 developed a fever (37.5°C) on her third day of life, and one neonate had an occasional cough. Throat and anal swab samples of neonates were repeatedly tested to exclude or confirm COVID-19 infection, and 2 neonates tested positive in the second of 4 tests. After the New Coronavirus Pneumonia Prevention and Control Program (seventh edition) published on March 4, 2020 [17], SARS-CoV-2 specific IgM and IgG were implemented. A total of 4 neonates were tested, of which 2 were positive.

During specific or symptomatic treatment, all neonates showed improvement on chest X-ray or CT images (Tables 4 and 5; Fig 2 and S1 Fig). Follow-up chest X-ray films in 3 cases (Patients 9, 10, 18) were performed showing increased lung markings and/or scattered obscure shadows. Before discharge, chest X-ray films in 4 cases (Patients 5, 9, 10, 12) indicated that pulmonary lesions had been completely or partially diminished, whereas the chest CT image in 1 neonate (Patient 18) had increased density in previously existing pulmonary lesions with interlobular septal thickening.

The average NICU stay was 13 days, but 3 neonates with abnormal radiological findings without COVID-19 infection had neonatal necrotizing enterocolitis (NEC) and were therefore admitted longer. These neonates (Patient 2, 14, 15) developed NEC after birth at 37+6, 40+1, 37+2 weeks’ gestation, respectively (Table 5). The first symptoms included bloody stools (Patient 2 and Patient 14, both at Day 4), repeated vomiting and bloating (Patient 15 at Day 2). Further, abdominal X-rays showed abnormalities including intermediate abdominal pneumatosis, and indistinct intestinal space (S2 Fig).

Discussion

Main findings

In this study, among 29 women with confirmed or clinical diagnosed COVID-19 infection, 5 neonates were diagnosed with a COVID-19 infection (2 confirmed and 3 suspected). None of these 5 neonates had contact with infected patients, except for their mothers during delivery, which suggests vertical and intrapartum transmission.

Results in context

Several case series have been reported focusing on the impact of COVID-19 on pregnant women and neonates [6-12]. Chen and colleagues [6] first evaluated the clinical characteristics of COVID-19 infection in 9 mother–neonate pairs. Amniotic fluid, cord blood, neonatal throat swab, and breastmilk samples were tested from 6 patients for SARS-CoV-2, and all were negative. In these case series or case reports, the majority COVID-19-infected pregnant women had mild symptoms and were delivered by CS. Further, all women had lung radiological changes, which is consistent with our results. Although in the study by Zhu and colleagues, 10 neonates experienced several clinical problems including premature labor, shortness of breath, thrombocytopenia, and even death [9]; in other reports, positive neonatal outcomes were minimal. Only 2 cases of confirmed neonatal COVID-19 infection have been reported [24]. One neonate was diagnosed at 17 days postdelivery after close contact with a COVID-19-infected mother and babysitter [25]. The other neonate was found to be infected 36 hours after a CS delivery after negative cord blood, amniotic fluid, and placenta SARS-CoV-2 RNA results [26].

In this present study, all neonates with COVID-19 infection were born via CS where both general hospitals had only 1 negative-pressure operating room. When the neonates were born through CS, they stayed unprotected in the operating room for about 30 minutes for observation before they were transferred to isolated neonatal wards. Although a guideline released by the Hubei government required immediate isolation of neonates from infected mothers [27], the 30 minutes’ observation had not been noticed by obstetricians. The contaminated air in the operation room might be the source of the viral transmission, although other transmission routes cannot be excluded.

Strengths and limitations

This is the first study to our knowledge to integrate the complete data of mothers and neonates to explore the association between maternal COVID-19 infection and neonatal COVID-19 infection or other health conditions. All women with confirmed or clinical diagnosed COVID-19 infections who gave birth at 2 of the 5 designated general hospitals between January 30 to March 10, 2020 during the most severe time of the epidemic in China were included in this study. The detailed clinical course of each hospitalized neonates was recorded and the condition of the nonhospitalized neonates was monitored by telephone interview, thus providing reliable follow-up data, which have eliminated the recall bias often found in retrospective studies. However, in the early stage of the outbreak, there was a shortage of COVID-19 test kits. As such, most neonates were only tested twice with throat and anal swabs. Only 4 neonates were tested for SARS-CoV-2 specific IgM and IgG. Ai and colleagues [28] reported chest CT had higher sensitivity in diagnosing a COVID-19 infection in comparison to qRT-PCR tests from swab samples in China. Although more than half of the pregnant women in this study were clinically diagnosed based on chest CT images due to the lack of PCR kits, we believe the diagnosis was accurate. Another limitation is the lack of tracheal aspirate to identify specific pathogens from the first 12 neonates with radiological features for pneumonia. This led to the uncertain etiology of the identified pneumonia. Because we found only 5 neonates with (suspected) COVID-19 infection, comparison between groups had limited statistical power.

Research implications

Our findings suggest maternal CRP levels may be associated with neonatal lung radiological changes, as antenatal CRP levels were higher in mothers of neonates who had abnormal radiological findings (with COVID-19 or without). CRP is the most commonly researched acute-phase reactant in infection and noninfectious inflammation. There is some evidence to suggest antenatal CRP levels are associated with pregnancy-related complications [29], mental disorders in offspring [30], infant birthweight [31], and neonatal CRP levels [32]. Although CRP cannot be transmitted to the fetus through the maternal–fetal interface, maternal inflammation can affect the fetal immune state including immune cells, cytokines, and chemokines [33].

In the 5 COVID-19-infected neonates in our study (Table 4), we found their clinical manifestations were very different from those of infected adults and even children [19]. Neonates had almost no symptoms, and it was difficult to judge the changes in white blood cells and lymphocytes because of the differing number of days since birth. In terms of the SARS-CoV-2 RNA tests in throat and anal swab samples, there may have been sampling errors and false negative or false positive results. As for the detection of the SARS-CoV-2 specific IgM and IgG, only 4 cases were tested in this study due to late arrival of the testing platform, which may become a powerful method for identifying the infections in the future. When comparing all the various diagnostic examinations, the chest CT images appear to be the most important for a diagnosis and prognosis of COVID-19 among neonates. The typical radiographic findings of COVID-19 pneumonia in those 5 infants were predominately manifested as focal or diffuse GGOs located in the peripheral regions, which were distinguishable from bacterial infection but nonspecific from other virus pneumonia, such as influenza A. After treatment, all neonates showed improvement on chest X-ray or CT images. However, in 1 neonate (Patient 18), we found the densities of previous existing lung lesions increased with interlobular septal thickening, suggested that interstitial fibrosis had developed and may influence pulmonary function in the future. As previously reported [34], CT scan is more sensitive than X-ray film in detecting pulmonary lesions which are usually overlapped by the shadow of the heart or hidden behind posterior region of the diaphragms. Considering the safety of ionizing and the need of avoid wasting a medical resource, it is urgent to develop an effective standard to screen infants and children for COVID-19.

Notably, although 12 of the 13 other hospitalized neonates presented radiological features for pneumonia through X-ray or CT, only 1 neonate had an occasional cough, and none of them had any of the usual symptoms associated with a SARS-CoV-2 infection. It seems that neonates born to mothers with COVID-19 had a significantly increased risk for pneumonia-like damage within 6 days of birth. Generally, the incidence rate of neonatal pneumonia is <1% among full-term infants and approximately 10% in preterm infants [35,36]. However, the neonates in this study had no specific symptoms of pneumonia, so no microbiological test had been implemented except for SARS-CoV-2. The increased radiological features for pneumonia may be due to false negative of SARS-CoV-2 PCR test, which has a 30% false negative rate [37]. For example, Patient 12 had a typical CT feature for COVID-19 infection, but her throat and anal swabs were all negative. As such, it is possible that some of these 12 neonates had a potential SARS-CoV-2 infection and that early tracheal aspirate should be obtained for specific pathogen identification. Further, inhalation of amniotic fluid and neonatal wet lung syndrome may also cause abnormal radiological findings. Following treatment, all the lesions shown in S1 Fig resolved, but it is unknown if any long-term effects will develop and warrants investigation.

For SARS-CoV-2 specific serum IgM and IgG, 2 neonates were positive (Patient 10 and 18) raising the concern of intrauterine transmission. Currently, SARS-CoV-2 is thought to primarily exist in the respiratory tract and to a lesser extent in the digestive system. Like other respiratory viruses, the positive rate of nucleic acid testing in blood is not high. The vertical transmission from mother-to-fetus via placenta usually requires a high replication level of virus in the blood. This may be the reason why no SARS-CoV-2 was found in the cord blood, amniotic fluid, or placenta as they were in previous studies [6,38]. When the SARS-CoV-2 specific IgM and IgG test in serum was proposed, neonates who had not been discharged were tested. IgM is the earliest synthesized and secreted antibody during human development. The fetus at the late stage of development begins to synthesize IgM, which is too large to be passed through the placenta and into the fetus. The rise of IgM is generally considered to be an indicator of intrauterine or perinatal infection. On the other hand, IgG appears to be passively transported from the mother to the fetus because it can pass through the placenta and can be synthesized by the infant after 3 months of age [39]. It is unfortunate both cases had no retained cord blood, placenta, or amniotic fluid samples so that we could test for the antibodies. Additional research is needed to further clarify vertical transmission.

In addition, 3 neonates developed NEC despite the lack of prematurity. Similar findings were found among the 5 infants born to infected women during the severe acute respiratory syndrome (SARS) outbreak [40]. One of the 5 infants born to SARS-infected women developed neonatal respiratory distress syndrome (NRDS) and jejunal perforation, and another developed NEC with ileal perforation shortly after birth. These 2 cases included extremely premature infants in which one was born at 26 weeks’ gestation, and the other was born at 28 weeks. The occurrence of NEC in this study is concerning and warrants further investigation.

Conclusions

Neonates born to COVID-19-infected women had an increased risk of COVID-19 and radiological features for pneumonia. Intrapartum and postpartum exposure to their mother may have played a role and intrauterine transmission should not be dismissed. Serum test of SARS-CoV-2 specific IgM and IgG is a valuable test to compensate for a false PCR result. The increased occurrence of necrotizing enterocolitis among neonates born to COVID-19-infected women warrants further investigation.

STROBE checklist of item that should be included in reports of cohort studies.

STROBE, Strengthening the Reporting of Observational Studies in Epidemiology.

(DOCX)

Click here for additional data file.

Analysis plan.

(DOCX)

Click here for additional data file.

Brief medical histories of 5 neonates with COVID-19 infection.

(DOCX)

Click here for additional data file.

Laboratory tests of all hospitalized neonates born to mother with COVID-19.

(DOCX)

Click here for additional data file.

Chest X-ray or CT (transverse plane) images of 13 neonates with radiological change in chest but who were not diagnosed with COVID-19.

Left panel of each case was the chest X-ray or CT performed after birth (within 3 days, mostly within 24 hours). Except one showing increased bilateral lung markings (H, Patient 11), the other 12 showed the typical manifestations of pneumonia. The main findings was diffuse or scattered patchy obscure shadows of unilateral or bilateral lungs, 5 cases with partial ground-glass opacities (G, I, J, K, M, Patient 8, 13, 14, 15, 17), 5 cases with peripheral focal consolidations (E, I, K, L, M, Patient 6, 13, 15, 16, 17), and one case with paramediastinal emphysema (E, Patient 6). Right panel of each case was the chest X-ray performed before discharge (Patient 11 was performed after discharge), of which 12 neonates with pneumonia-like radiological changes showed absorption of lesions. Four cases showed slightly increasing lung markings (B, C, D, F, Patient 2, 3, 4, 7). Only one case showed scattered patchy blurry shadows (K, Patient 15). The other one still showed increased bilateral lung markings (H, Patient 11). All images have been de-identified to protect patient privacy. COVID-19, coronavirus disease 2019; CT, computed tomography.

(TIF)

Click here for additional data file.

Abdominal X-ray images of 3 neonates with necrotizing enterocolitis.

(A, Patient 2) Abdominal X-ray images at Day 5 showed intermediate abdominal pneumatosis, indistinct intestinal space between bowels in the middle and lower abdomen, and the presence of “bubble sign”. (B, Patient 14) Abdominal X-ray images at Day 5 showed abdominal pneumatosis; indistinct intestinal space between bowels in the right lower abdomen, and slightly linear and bubble-like radiolucencies. (C, Patient 15) Abdominal X-ray images at Day 20 showed mild abdominal pneumatosis, which was mainly located in the colon, and slightly indistinct intestinal space between bowels in the left lower abdomen. All images have been de-identified to protect patient privacy.

(TIF)

Click here for additional data file.

9 Apr 2020

Dear Dr Huang,

Thank you for submitting your manuscript entitled "Neonatal outcome in 29 pregnant women with COVID-19" for consideration by PLOS Medicine.

Your manuscript has now been evaluated by the PLOS Medicine editorial staff as well as by an academic editor with relevant expertise and I am writing to let you know that we would like to send your submission out for external peer review.

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Please also confirm whether this is a separate cohort from the one reported in JAMA Pediatrics recently:

https://jamanetwork.com/journals/jamapediatrics/fullarticle/2763787

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PLOS Medicine

30 Apr 2020

Dear Dr. Huang,

Thank you very much for submitting your manuscript "Neonatal outcome in 29 pregnant women with COVID-19" (PMEDICINE-D-20-01174R1) for consideration at PLOS Medicine.

Your paper was evaluated by a senior editor and discussed among all the editors here. It was also discussed with an academic editor with relevant expertise, and sent to four independent reviewers, including a statistical reviewer. The reviews are appended at the bottom of this email and any accompanying reviewer attachments can be seen via the link below:

[LINK]

In light of these reviews, I am afraid that we will not be able to accept the manuscript for publication in the journal in its current form, but we would like to consider a revised version that addresses the reviewers' and editors' comments. Obviously we cannot make any decision about publication until we have seen the revised manuscript and your response, and we plan to seek re-review by one or more of the reviewers.

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6- The entire manuscript would benefit from a thorough check for grammar, spelling, and clarity.

7- In the last sentence of the Abstract Methods and Findings section, please describe the main limitation(s) of the study's methodology.

8- Abstract Conclusions: Please be more specific, and address the study implications without overreaching what can be concluded from the data; the phrase "In this study, we observed ..." may be useful.

9- The Introduction could benefit with more background on what is known and not known about COVID-19 in pregnant women, infants, and other populations. Additionally, a bit more on the setting and population of the current study would be useful.

10- Please include the Ethical approval and Informed consent sections in the Methods.

11- Results lines 197-198: please present numerators and denominators for percentages.

12- Line 206: “uneventful follow-up” could be more specific.

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Comments from the reviewers:

Reviewer #1: I confine my remarks to statistical aspects of this paper.

These were very simple but appropriately so and I recommend publication

Peter Flom

Reviewer #2: The article indeed offer a series of relatively complete data,including Maternal demographic characteristics, delivery course, symptoms, and laboratory tests. However some researchs about the outcome of neonates born to infected women have published, the innovation of the paper needs to be improved. Suggest to transfer to Letter format.

Reviewer #3: REVIEWER COMMENTS TO AUTHOR

Thank you for the opportunity to review this paper.

There is no doubt that the COVID-19 pandemic will be of interest to PLOS Medicine's wide general audience. I believe the content of this manuscript will lead to a substantial advance in clinical management of pregnant women (and their neonates) with COVID-19. Further, the data presented provide a substantial new insight into the pathogenesis of COVID-19. I support the publication of this manuscript.

General comments, strengths and weaknesses

I believe the authors have done a good job pulling together disparate data from two hospitals with multiple clinicians involved. Whilst I think the 17% vertical/neonatal transmission is interesting, the radiologic changes of pneumonia in the non-COVID neonates are remarkable. I think the authors should make more of this unique finding. What does it mean to have 12/30 neonates from COVID mothers with radiologic pneumonia in relatively well neonates? What is the cause of the radiologic changes? What are the potential diagnoses responsible for these radiologic changes?

Specific points:

1. What did the researchers do and find?

a. Line 51 - while the other 12 neonates WERE discharged after birth ….

b. Line 53 - It would be easier to understand if you wrote 'Five of the 18 hospitalized neonates…'

c. I think you should also put in a comment about the NEC in the COVID negative neonates who were not preterm.

2. What do these findings mean?

a. I think the vertical transmission and radiologic features of pneumonia should be two separate points. It is interesting that 17% of neonates developed COVID-19. It is remarkable that 12/13 (92%) of the non-COVID neonates had radiologic signs of pneumonia. This should be emphasised.

3. Abstract

a. Line 71 - manifestations TO non-pregnant women

b. Lines 88-90 - this sentence does not make sense.

c. Line 91 - presented WITH radiological features…

d. Line 96 - radiological FEATURES OF pneumonia.

4. Introduction - clear

5. Methods

a. Line 136 remove WAS

b. Line 144 maternal history should be MATERNAL PARITY

6. Results

a. Line 196 - suggest AVAILABLE rather than supply

b. Line 221-222 - S1 Table is really important. I think this should be upgraded to Table 5

c. Line 242 - I think you should add after …abnormal radiological findings… (without diagnosis of COVID-19)

7. Discussion

a. Line 265-266 - 'In the present study, a detailed item might play a role' does not make sense. I suggest re-writing the sentence.

b. Line 289 - 'false negatives or false positives.' I suggest FALSE NEGATIVE OR FALSE POSITIVE RESULTS.

c. Line 291 - I suggest changing 'proposal' to THE LATE ARRIVAL OF THE TESTING PLATFORM.

d. Lines 312-314. What does the 'pneumonia-like damage' mean to the neonate in the short term and the long term? What do you think they have as their diagnoses?

8. Conclusions - clear

Reviewer #4: The paper describes infants of 29 mothers with Covid-19. Five infants had Covid-19 (2 confirmed and 3 suspected cases). Detailed description is provided with respect to infants' symptoms, laboratory measures, and x-ray/CT images. Maternal pregnancy complications and delivery are also described. I have relatively minor comments.

Comments:

1. Abstract: Line 74. A retrospective cohort study is an analytical epidemiological study that includes a comparison group (exposed vs unexposed). I suggest this study is a descriptive follow-up study.

2. Abstract: Can you, please, indicate how many hospitalized infants were hospitalized because they needed hospitalization and how many just for the quarantine. Would these infants be otherwise discharged to home if parents did not opt for the quarantine in the hospital?

3. It would be nice to define the diagnostic criteria for Covid-19 in mothers and in infants (expert consensus) in the Introduction or Methods (the referenced literature may not be easily accessible to all). A brief description of typical signs of Covid-19 pneumonia and how it differs from other pneumonias in newborns would be also appreciated by general medical audience.

4. Results Line 193-197: there were 29 women with Covid-19, 16 were diagnosed only by chest CT. Covid-19 symptoms were present only among 14 women. It seems that chest CT was the only diagnostic sign of Covid-19 in some mothers in this study. Is it a reliable?

5. Can you, please, describe the NEC cases in more detail in the results section? Specifically, their gestational age at birth and how many days from birth (to NEC diagnosis)?

6. Can you please add gestational age at delivery to Table 2 (I suggest in categories, e.g., 20-33, 34-36, 37-38, 39-41, 42+ weeks)?

Minor comments:

Line 174: Please use the reference only or specify by the last name, eg "… following the paper by Nissen..."

Any attachments provided with reviews can be seen via the following link:

[LINK]

8 May 2020

Submitted filename: Response to Reviewers.docx

Click here for additional data file.

27 May 2020

Dear Dr. Huang,

Thank you very much for re-submitting your manuscript "Neonatal Outcome in 29 Pregnant Women with COVID-19: A Retrospective Study" (PMEDICINE-D-20-01174R2) for review by PLOS Medicine.

I have discussed the paper with my colleagues and the academic editor. I am pleased to say that provided the remaining editorial and production issues are dealt with we are planning to accept the paper for publication in the journal.

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[LINK]

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Please also check the guidelines for revised papers at http://journals.plos.org/plosmedicine/s/revising-your-manuscript for any that apply to your paper. If you haven't already, we ask that you provide a short, non-technical Author Summary of your research to make findings accessible to a wide audience that includes both scientists and non-scientists. The Author Summary should immediately follow the Abstract in your revised manuscript. This text is subject to editorial change and should be distinct from the scientific abstract.

We expect to receive your revised manuscript within 1 week. Please email us (plosmedicine@plos.org) if you have any questions or concerns.

We ask every co-author listed on the manuscript to fill in a contributing author statement. If any of the co-authors have not filled in the statement, we will remind them to do so when the paper is revised. If all statements are not completed in a timely fashion this could hold up the re-review process. Should there be a problem getting one of your co-authors to fill in a statement we will be in contact. YOU MUST NOT ADD OR REMOVE AUTHORS UNLESS YOU HAVE ALERTED THE EDITOR HANDLING THE MANUSCRIPT TO THE CHANGE AND THEY SPECIFICALLY HAVE AGREED TO IT.

Please ensure that the paper adheres to the PLOS Data Availability Policy (see http://journals.plos.org/plosmedicine/s/data-availability), which requires that all data underlying the study's findings be provided in a repository or as Supporting Information. For data residing with a third party, authors are required to provide instructions with contact information for obtaining the data. PLOS journals do not allow statements supported by "data not shown" or "unpublished results." For such statements, authors must provide supporting data or cite public sources that include it.

If you have any questions in the meantime, please contact me or the journal staff on plosmedicine@plos.org.

We look forward to receiving the revised manuscript by Jun 03 2020 11:59PM.

Sincerely,

Thomas McBride, PhD

Senior Editor

PLOS Medicine

plosmedicine.org

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Requests from Editors:

1- Thank you for providing text excerpts for the STROBE checklist items. Please either provide the full excerpt (no “…”) or describe the section and paragraph where the item appears in the main text (e.g., “Methods, paragraph 1”).

2- Thank you for providing information on how to find the dataset. However, the file (listed as a .xls) did not open on my computer. Please make sure the format is correct.

3- Please add "in Wuhan, China" to the title.

4- Please add summary demographic details for the mothers to the abstract.

5- Abstract, line 113 (of the marked up document): please edit to: “Neonates were hospitalized if they *had* signs *of COVID-19* (5 cases) or their guardians agreed *to* a hospitalized quarantine…” Please confirm whether “signs” or “symptoms” is more accurate in this sentence.

6- Please edit the Abstract Conclusions. While we appreciate providing a specific response here, the figures presented are better suited to the Abstract Methods and Findings. A more appropriate Conclusion could be: In this study, we observed that COVID-19 or radiological features of pneumonia in some, but not all, neonates born to women with COVID-19. These findings suggest that intrauterine or intrapartum transmission is possible.”

7- Thank you for providing an Author Summary. However, this should not simply restate the information in the Abstract. Please edit the “What did the researchers do and find?” and “What do these findings mean?” to provide a non-technical summary of the findings and implications. Please also limit the sections to 2-3 bullet points each.

8- Additionally, please adjust the “What did the researchers do and find” section to reflect the reviewer comments about the neonatal pneumonia findings which were not conclusive and could be a little misleading.

9- Introduction, line 178: more accurate to say “...of all women with *confirmed* COVID-19 infectons…”?

10- Introduction line 180: as this is not a randomized trial, please refrain from using causal language (eg “effect”). Instead please change to “... to assess neonatal outcomes associated with maternal COVID-19 ifection.”

11- At line 210, we suggest adapting the text to "For this retrospective study in clinical practice, the requirement for written informed consent was waived by the ethics committee.".

12- In the results section of your main text, please state the breakdown of the neonates by sex (we may have missed this in the text or tables).

13- At line 387, please make that "had contact".

14- At line 388, please make that "... which suggests vertical and intrapartum transmission." or similar.

15- At line 439, please avoid claiming "the first", for example, and where necessary please amend the text to "to our knowledge the first" or similar. E.g, “This is the first study to our knowledge to explore the association between maternal COVID-19 infection and neonatal COVID-19 infection or other health conditions.”

16- At lines 107 & 481, please make that "COVID-19-infected women/neonates" or similar.

17- Discussion, line 440: please change to: “All mothers with confirmed COVID-19 infections who gave birth…”. Please also provide a more specific time frame than “around February 2020”, and specify this includes all mothers who gave birth at a hospital in China, allowing for the possibility of births that were not identified and included in this study.

18- Line 469: more accurate to say “...limited statistical power.”?

19- Line 472: “Our findings suggest…”

20- Line 481: “In *the* five COVID-19 neonates…”

21- Please incorporate your response to reviewer 2 into the second section of the Discussion, citing the most current studies on pregnant women with COVID-19 and their children, and placing your findings in the context of these other studies.

22- In the Discussion, please discuss the limitations in a bit more depth, particularly those around the radiological findings among neonates and the diagnosis of some mothers without PCR testing.

23- S1 and S2 Table seem to be missing, please upload. Page limits should not be an issue, S1 Table can be added to the main text as Table 5.

24- Please present all new results in the Results section. The section beginning at line 507 of the Discussion seems to present new information on the follow-up of several neonates that should be in the Results section.

25- Rather than using “Case X”, please refer to “patients” or “individuals”.

26- Line 359: PLOS does not allow for data that is “not shown”. Please add this information to the tables.

27- Please remove the information on conflicts of interest, funding and data availability from the end of the main text. This information will appear in the metadata in the event of publication (via the submission form).

18 Jun 2020

Submitted filename: Response to Editors.docx

Click here for additional data file.

24 Jun 2020

Dear Prof. Huang,

On behalf of my colleagues and the academic editor, Dr. Jenny E Myers, I am delighted to inform you that your manuscript entitled "Neonatal Outcome in 29 Pregnant Women with COVID-19: A Retrospective Study in Wuhan, China" (PMEDICINE-D-20-01174R3) has been accepted for publication in PLOS Medicine.

PRODUCTION PROCESS

Before publication you will see the copyedited word document (in around 1-2 weeks from now) and a PDF galley proof shortly after that. The copyeditor will be in touch shortly before sending you the copyedited Word document. We will make some revisions at the copyediting stage to conform to our general style, and for clarification. When you receive this version you should check and revise it very carefully, including figures, tables, references, and supporting information, because corrections at the next stage (proofs) will be strictly limited to (1) errors in author names or affiliations, (2) errors of scientific fact that would cause misunderstandings to readers, and (3) printer's (introduced) errors.

If you are likely to be away when either this document or the proof is sent, please ensure we have contact information of a second person, as we will need you to respond quickly at each point.

PRESS

A selection of our articles each week are press released by the journal. You will be contacted nearer the time if we are press releasing your article in order to approve the content and check the contact information for journalists is correct. If your institution or institutions have a press office, please notify them about your upcoming paper at this point, to enable them to help maximize its impact.

PROFILE INFORMATION

Now that your manuscript has been accepted, please log into EM and update your profile. Go to https://www.editorialmanager.com/pmedicine, log in, and click on the "Update My Information" link at the top of the page. Please update your user information to ensure an efficient production and billing process.

Thank you again for submitting the manuscript to PLOS Medicine. We look forward to publishing it.

Best wishes,

Thomas McBride, PhD

Senior Editor

PLOS Medicine

plosmedicine.org