Progesterone Level On The Day Of Trigger And Fresh Embryo Transfer.

There is no consensus on whether serum progesterone (P4) levels should be measured during IVF cycles. Studies that have suggested the benefit of measuring P4 have identified different thresholds above which there may be a reduction in implantation rates (IRs). However, the majority of these studies did not adjust for critical confounding factors. Therefore, we investigated whether serum P4 levels on the day of trigger influence the implantation potential of embryos by including only young women who had transfers of good-quality blastocyst(s) on day 5. Of note, progesterone levels did not influence the decision to proceed with embryo transfer because it was measured after the completion of cycles using stored serum collected on the day of trigger. Retrospective cohort study. All fresh IVF-ET cycles performed at our center between January 2014 and December 2017 were reviewed. We included women ≤35 years who had transfers of good-quality blastocysts on day 5. Good-quality was defined as ≥2BB (2-6BB, 2-6AA, 2-6AB, 2-6BA) according to Gardner’s grading system. The IR and live birth rate (LBR) were compared between patients at different P4 thresholds on the day of trigger. χ2 and Fisher’s exact tests were used for categorical variables. Student’s t test was used for parametric data. Odds ratios (OR) with 95% confidence intervals (CI) were calculated. Values were expressed as mean ± standard deviation. A total of 739 fresh IVF cycles for women who had a transfer of 1 or 2 good-quality blastocysts on day 5 were included. Their mean age was 31.7 ± 2.8 years, their body mass index was 23.5 ± 3.8 kg/m2, and the number of oocytes retrieved was 16.9 ± 7.0. Women who had a serum P4 level ≥2 ng/mL on the day of trigger had a significantly lower LBR (10% vs. 58.2%; P=0.003) and IR (15% vs. 59.6%, respectively; P=0.002) compared to women whose P4 levels were <2 ng/mL. The difference in LBR remained significant after adjusting for the number of embryos transferred (adjusted OR = 12.5; 95% CI = 1.7-91.2). A P4 level <1.5 ng/mL was associated with a comparable LBR (58.5% vs. 52.6%, respectively; P=0.4) and IR (60.3% vs. 47.4%, respectively; P=0.2) to those of women with P4 levels of 1.5-2 ng/mL. Of note, women with a P4 ≥2 ng/mL had a comparable estradiol level on the day of trigger (1947 ± 711 vs. 2224 ± 865 pg/mL, respectively; P=0.3) and number of oocytes harvested (14.4 ± 6.4 vs. 16.9 ± 7.1, respectively; P=0.2) to those of women with a P4 <2 ng/mL. An elevated serum P4 level (≥2 ng/mL) on the day of trigger decreases embryo implantation potential during fresh transfer. Elevation of the P4 level during stimulation does not correlate with the estradiol level or the number of oocytes retrieved. Therefore, these parameters do not predict elevation in the P4 level, which should be measured to identify women who may benefit from freeze-all embryos due to embryo–endometrium dyssynchrony.