Progesterone elevation and probability of pregnancy after IVF: a systematic review and meta-analysis of over 60 000 cycles.

BACKGROUND The aim of this meta-analysis was to evaluate the association of progesterone elevation (PE) on the day of hCG administration with the probability of pregnancy in fresh, frozen-thawed and donor/recipient IVF cycles. METHODS A literature search in MEDLINE, SCOPUS, COCHRANE CENTRAL and ISI Web of Science was performed aiming to identify studies comparing the probability of pregnancy in patients with or without PE after ovarian stimulation with gonadotrophins and GnRH analogues. Standard meta-analytic methodology was used for the synthesis of results and meta-regression for exploration of heterogeneity. RESULTS Sixty-three eligible studies were identified evaluating 55 199 fresh IVF cycles, nine studies evaluating 7229 frozen-thawed cycles and eight studies evaluating 1330 donor/recipient cycles. In fresh IVF cycles, a decreased probability of pregnancy achievement was present in women with PE (when PE was defined using a threshold ≥ 0.8 ng/ml) when compared with those without PE. The pooled effect sizes were 0.8-1.1 ng/ml: odds ratio (OR) = 0.79; 1.2-1.4 ng/ml: OR = 0.67; 1.5-1.75 ng/ml: OR = 0.64; 1.9-3.0 ng/ml: OR: 0.68 (P < 0.05 in all cases). No adverse effect of PE on achieving pregnancy was observed in the frozen-thawed and the donor/recipient cycles. CONCLUSIONS Based on the analysis of more than 60 000 cycles, it can be supported that PE on the day of hCG administration is associated with a decreased probability of pregnancy achievement in fresh IVF cycles in women undergoing ovarian stimulation using GnRH analogues and gonadotrophins. On the other hand, an adverse effect of PE does not seem to be present in frozen-thawed and donor/recipient cycles.