Effect of progesterone on hCG day-to-basal progesterone ratio on live birth rate in long agonist fresh IVF/ICSI cycles: a 5-year, single-center study of more than 10,000 cycles.

OBJECTIVE: To investigate whether the ratio of the serum progesterone level on the day of human chorionic gonadotrophin (hCG) administration to the basal serum progesterone level (PhCG/Pbasal) is a predictor of pregnancy outcome during in vitro fertilization (IVF). METHODS: A total of 12,708 cycles were performed in 9747 patients between 19 and 36 years of age who were undergoing controlled ovarian stimulation from October 2011 to July 2016 for their first or second attempts at IVF followed by fresh embryo transfer (ET). hCG was administered 36 h before oocyte retrieval to trigger final oocyte maturation. The serum progesterone level was measured on menstrual cycle days 2-4 (basal progesterone, Pbasal) and on the day of hCG administration (PhCG). PhCG/Pbasal was calculated. Live birth rates were compared among various ordinal PhCG/Pbasal intervals (< 0.5, 0.5-1.0, 1.0-1.5, 1.5-2.0, 2.0-2.5, > 2.5). RESULTS: The average age of the patients recruited was 29.9 years. The average basal progesterone level was 0.8 ng/ml, while the average progesterone level on the day of hCG administration was 0.9 ng/ml. The live birth rates (according to the abovementioned ordinal PhCG/Pbasal intervals) were 47.3, 49.9, 47.8, 46.3, 45.5 and 44.0%, respectively. The live birth rates were significantly higher for patients with PhCG/Pbasal between 0.5-1.0 (OR = 1.14, 95% CI, 1.02-1.27, p = .02). CONCLUSIONS: PhCG/Pbasal between 0.5-1.0 predicts a higher live birth rate in IVF. Both PhCG/Pbasal and P on hCG day is less predictive value for predicting live birth rate.