Objective: To investigate the effect of low progesterone (P) level on the day of human chorionic gonadotropin (hCG) injection on the outcome of in vitro fertilization (IVF) with GnRH- agonist (GnRH-a) long protocol.
Methods: A retrospective study was conducted in a reproductive medicine center of University-affiliated teaching hospital. 1115 women included were divided into two groups according to the P level: Group 1 (233 women with P level ≤ 0.5 ng/ml, and Group 2 (882 women with P level >0.5, ≤ 1.5 ng/ml). No. of oocyte retrieved, fertilization rate, implantation rate, and clinical pregnancy rate were compared between the two groups.
Results: Compared with Group 2, Group 1 had significantly decreased number of oocyte retrieved (9.84 ± 4.01 vs. 11.83 ± 4.06, P=0.000) and significantly increased implantation rate (39.4% vs. 34.1%, P=0.037). Group 1 had an increased trend of clinical pregnancy rate (55.8% vs. 49.9%, P=0.109) compared with that of Group 2. However, the fertilization rates were similar between Group 1 and Group 2 (76.6% vs. 77.0%, P=0.725).
Conclusions: Low P level on the day of hCG injection may have a trend towards higher implantation and clinical pregnancy rates after IVF cycles with GnRH-a long protocol. Therefore, we should not worry about the low P on hCG injection day.
Progesterone, In vitro fertilization, Pregnancy outcome