Influence of GnRH antagonist in reproductive women on in vitro fertilization and embryo transfer in fresh cycles.

The aim of the present study was to evaluate the influence of a gonadotropin-releasing hormone (GnRH) antagonist compared with a GnRH agonist on in vitro fertilization (IVF) cycle outcome in reproductive women. The characteristics of treatment and outcomes of pregnancy were retrospectively compared between the antagonist (GnRH-A, antagonist group) and agonist (GnRH-a, agonist group) regimens. The area under the curve (AUC) of receiver operating characteristic (ROC) curves was also used to evaluate whether the endometrial thickness (cm), progesterone (P) level (ng/ml) and estradiol (E2) level (pg/ml) on the day of human chorionic gonadotropin (hCG) administration (hCG day) had the ideal sensitivity and specificity for predicting clinical pregnancy. There were no significant differences in the baseline profiles of luteinizing hormone, E2 and P between the GnRH-A and GnRH-a groups (P=0.646, 0.224 and 0.119, respectively). However age, body mass index and follicle stimulating hormone (FSH) level significantly differed between the two groups (P<0.001, =0.025 and <0.001, respectively). Regarding treatment, there were significant differences in the stimulation duration (recombinant FSH days of usage), dose of gonadotrophins, E2, and P levels on hCG day, endometrial thickness on hCG day, mean number of total oocytes retrieved, mean number of two pronuclei oocytes, mean number of embryos available and mean number of embryos transferred (all P<0.001). The rate of clinical pregnancy was lower with the GnRH antagonist than with the GnRH agonist (P<0.001). Additionally, the live birth rate in the GnRH-A group was significantly lower than that in the GnRH-a group (P<0.001). The rate of ectopic pregnancy did not differ significantly between the treatment groups (P=0.840). However, the rate of ovarian hyperstimulation syndrome (OHSS) in group GnRH-A was significantly lower than that in group GnRH-a (P=0.039). Therefore, in the present series of patients who underwent IVF embryo transfer cycles, a GnRH antagonist protocol was associated with significantly lower rates of clinical pregnancy and live birth compared with a GnRH agonist protocol; however, the rate of OHSS was significantly lower with GnRH antagonist compared with GnRH agonist. Furthermore, the results of the influence of endometrial thickness on clinical pregnancy, based on the ROC curve (AUC), demonstrated that the AUC was 0.553 [95% confidence interval (CI): 0.521-0.585], and with a cutoff of 9.25 cm, the Youden index [sensitivity-(1-specificity)] was 0.085. The results of the influence of E2 level on hCG day on the clinical pregnancy rate revealed an AUC of 0.613 (95% CI: 0.581-0.644), and with a cutoff of 1,520 pg/ml, the Youden index was 0.184. The results of the influence of P level on hCG day (ng/ml) on the clinical pregnancy rate revealed an AUC of 0.526 (95% CI: 0.494-0.558), and with a cutoff of 0.415 ng/ml, the Youden index was 0.061. These results of the ROC curve analyses demonstrated that neither the endometrial thickness nor the E2 and P levels on hCG day had the ideal sensitivity or specificity for predicting clinical pregnancy.