Comparison the effects of progestin-primed ovarian stimulation (PPOS) protocol and GnRH-a long protocol in patients with normal ovarian reserve function.

OBJECTIVE: To compare the effects of progestin-primed ovarian stimulation (PPOS) protocol and GnRH-a long protocol in infertility patients with normal ovarian reserve function undergoing invitro fertilization and embryo transfer.

METHODS: A retrospective cohort study was conducted to analyze the clinical data of 2013 cycles of patients with normal ovarian reserve function who underwent invitro fertilization/intracytoplasmic sperm injection-embryo transfer (IVF/ICSI-ET) in the Department of Human Reproductive Center, Renmin Hospital, Hubei University of Medicine from January 2018 and June 2020. The PPOS protocol group included 679 cycles and GnRH-along protocol group included 1334 cycles, the pregnancy outcomes were compared between the two groups.

RESULTS: The duration of Gn used and total Gn used dosage in the PPOS protocol group were less than those in the GnRH-along protocol group (Duration of Gn used: 10.05 ± 1.48 vs 11.90 ± 1.85 d, p  < 0.001; Total Gn used dosage: 1944.49 ± 533.61 vs 2661.34 ± 987.97 IU, p  < 0.001); The LH levels were significantly higher on HCG trigger day in PPOS protocol compared to GnRH-a long protocol (2.8 ± 1 ± 1.07 vs 1.01 ± 0.62 IU/L, p  < 0.001), the E2 levels on HCG trigger day in PPOS protocol group was lower than that in the GnRH-a long protocol group (2135.92 ± 1387.00 vs 2417.01 ± 1010.70 pg/mL, p  < 0. 001). The number of oocytes retrieved in the PPOS protocol group was lower than that in the GnRH-along protocol group (8.03 ± 2.86 vs 9.47 ± 2.64, p  < 0.001). No significant differences were found in pregnancy outcome including clinical pregnancy rate, early miscarriage rate and ectopic pregnancy rate between the two group ( p  > 0.05); In addition, no severe OHSS occurred in the PPOS protocol group during ovulation induction, while 11 patients of severe ovarian hyperstimulation syndrome (OHSS) occurred in GnRH-a long protocol group ( p  < 0.001).

CONCLUSION: The clinical efficacy of PPOS protocol combining embryo cryopreservation is comparable to that of GnRH-a long protocol in patients with normal ovarian reserve function, and the PPOS protocol is able to reduce the incidence of severe OHSS significantly.