progesterone/estradiol ratio as a predictor in the art cycles with premature progesterone elevation on the day of hcg trigger

background: the purpose of the study was to evaluate the role of progesterone/ estradiol (p4/e2) ratio as a predictive tool for clinical pregnancy in art cycles with a premature progesterone rise of >1.5 ng/ml on the day of human chorionic gonadotropin (hcg) trigger. methods: retrospective analysis was done on 569 fresh embryo transfer cycles from january 2011 to december 2012 at the infertility unit of a tertiary care hospital. age, bmi, number of cycles and number of clinical pregnancies have been considered. results: the overall clinical pregnancy rate per embryo transfer was 42.8% (244/569). the clinical pregnancy rate in the 36 cycles with progesterone (p4) level >1.5 ng/ml was significantly lower than the 533 cycles with normal p4 ≤1.5 ng/ml (22.2% vs. 44.2%; p=0.0092). the 36 cycles with progesterone level >1.5 ng/ml were divided into subgroups of p4/e2 >1 (n=20) and p4/e2 ≤1 (n=16). the 20 cycles with p4/e2 >1 and p4 >1.5 ng/ml had a significantly lower pregnancy rate than the cycles with p4 ≤1.5 ng/ml (15% vs. 42.8%; p=0.0103). the 15 cycles with p4/e2 ≤1 and p4 >1.5 ng/ml had a similar pregnancy rate as the cycles with p4 ≤1.5 ng/ml. conclusion: a premature progesterone elevation in art cycles is possibly associated with lower clinical pregnancy rates; this adverse impact of elevated progesterone seems to be limited mainly to a subgroup with an elevated p4/e2 ratio >1.