Mid-luteal progesterone concentrations are associated with live birth rates during ovulation induction

This retrospective study investigated whether mid-luteal serum progesterone concentrations are associated with live birth rates in women with WHO group II anovulatory infertility undergoing ovulation induction. Data were from women (n=335) stimulated with gonadotrophins using a low-dose step-up protocol, of which women with presumptive ovulation (n=279), defined as a mid-luteal progesterone concentration ⩾7.9ng/ml (⩾25nmol/l; range 7.9-194ng/ml) were included. Of the women with presumptive ovulation, 57 (20.4%) had a live birth and their serum mid-luteal progesterone concentration was significantly (P=0.016) higher than that of the non-live birth group. There were significant associations between the number of large (⩾15mm) and medium-sized follicles (12-14mm) at human chorionic gonadotrophin administration and the mid-luteal progesterone concentration (P