High progesterone/estradiol ratio in follicular fluid at oocyte aspiration for in vitro fertilization as a predictor of possible pregnancy

Eighteen women undergoing in vitro fertilization (IVF) procedures were studied. All had optimal (900 to 1600pg/ml) peak serum estradiol (E 2 ) response to the same stimulation regimen with clomiphene citrate and menotropins; fertilization rate was above 64%; and two to four embryos in two to eight cell stages were replaced in each patient. All were considered to have optimal chances for conception. The authors compared progesterone (P), E 2 , and P/E 2 ratio in serum and follicular fluid (FF) at the time of oocyte aspiration in eight patients who conceived (group I) and ten who did not (group II). Mean serum P and E 2 levels and serum P/E 2 ratio were not significantly different between the groups. In contrast, mean FF P concentrations (ng/ml) were significantly ( P 2 ratio (19.0 versus 11.8; P 2 concentrations between the groups. These data indicate that in IVF cycles with optimal serum E 2 response to the stimulation protocol, FF P and P/E 2 ratio at the time of oocyte aspiration may be predictive of subsequent implantation and pregnancy.