Premature progesterone elevation during the early and mid-follicular phases in fresh in vitro fertilization (IVF) cycles is associated with lower live birth, clinical pregnancy, and implantation rates

Purpose Evaluate follicular phase progesterone elevation (≥ 1.5 ng/mL) prior to trigger during IVF stimulation and its effects on live birth rate (LBR), clinical pregnancy rate (CPR), and implantation rate (IR) in fresh IVF cycles. Methods This was a retrospective cohort study within an academic clinic. A total of 6961 fresh IVF and IVF/ICSI cycles from October 1, 2015 to June 30, 2021 were included and grouped by progesterone (PR) prior to trigger: PR < 1.5 ng/mL (low PR group) and PR ≥ 1.5 ng/mL (high PR group). Main outcome measures included LBR, CPR, and IR. Results Among all cycle starts, 1568 (22.5%) were in the high PR group and 5393 (77.5%) were in the low PR group. Of the cycles which proceeded to an embryo transfer, 416 (11.1%) were in the high PR group and 3341 (88.9%) were in the low PR group. The high PR group had significantly lower IR (RR 0.75; 95% CI 0.64–0.88), CPR (aRR 0.74; 95% CI 0.64–0.87), and LBR (aRR 0.71; 95% CI 0.59–0.85) compared to the low PR group. When stratified by progesterone on the day of trigger (TPR), there was a clinically notable decrease in IR (16.8% vs 23.3%), CPR (28.1% vs 36.0%), and LBR (22.8% vs 28.9%) in the high PR group compared to the low PR group even when TPR < 1.5 ng/mL. Conclusions In fresh IVF cycles in which TPR < 1.5 ng/mL, progesterone elevation ≥ 1.5 ng/mL at any point in time prior to trigger negatively impacts IR, CPR, and LBR. This data supports testing of serum progesterone in the follicular phase prior to trigger, as these patients may benefit from a freeze-all approach.