Premature progesterone rise negatively correlated with live birth rate in IVF cycles with GnRH agonist: an analysis of 2,566 cycles.

OBJECTIVE: To investigate the occurrence of premature progesterone rise (PPR) in GnRH agonist long or short protocol, address the relationship between circulating P levels and live birth rates, and explore the possible mechanism through which PPR affects clinical outcomes and the possible factors related to the occurrence of PPR.
DESIGN: Retrospective analysis.
SETTING: Reproductive medicine center of a public hospital. PATIENT(S): A total of 2,566 patients receiving in vitro fertilization/intracytoplasmic sperm injection treatment with GnRH agonist long or short protocol. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Live birth rates. RESULT(S): The corresponding incidence of PPR in long or short protocol was 22.86% (393/1,719) or 27.63% (234/847) with the cutoff value of 1.2 ng/mL or 2.0 ng/mL, respectively, being used to define PPR. Live birth rates decreased under the condition of PPR (40.65% vs. 29.77% in long protocol; 30.18% vs. 23.50% in short protocol). Logistic regression analysis showed that serum P level on the day of hCG administration was a strong predictor of live birth rate in both long and short protocols. Live birth rates in frozen embryo transfer cycles had no significant difference between groups with or without PPR (29.31% vs. 25.35% in long protocol; 24.84% vs. 24.22% in short protocol). Multivariate regression analysis showed that exogenous gonadotropin dose, the duration of stimulation, E(2) and LH levels on the day of hCG administration, the number of oocytes retrieved, and basal FSH level were all involved in PPR. CONCLUSION(S): In GnRH agonist cycles, PPR negatively correlated with live birth rate in fresh embryo transfer cycles, although no adverse impact on frozen embryo transfer was observed, implying that PPR may have deleterious effects on endometrial receptivity.