Role of the endocrine profile for the achievement of pregnancy with IVF.

The predictive value of pre-ovulatory hormones for achievement of pregnancy has been extensively evaluated in assisted reproductive technologies. Currently, no high-quality evidence exists to support or deny an association between oestradiol levels on the day of human chorionic gonadotrophin (HCG) administration and pregnancy achievement in IVF cycles. Retrospective studies appear to support the lack of such an association. Progesterone elevation on the day of HCG administration does not appear to be associated with the probability of clinical pregnancy in women undergoing IVF. Finally, no retrospective studies exist to suggest that low endogenous midfollicular LH concentrations are associated with a significantly decreased probability of ongoing pregnancy beyond 12 weeks of gestation in IVF. In two prospective studies, high endogenous LH concentrations during down-regulation were associated with a decreased probability of ongoing pregnancy beyond 12 weeks of gestation. Existing studies evaluating the association between single measurements of pre-ovulatory hormones and the achievement of pregnancy are of low quality and cannot lead to solid conclusions. Based on the available literature, it appears that no association exists between single assessments of oestradiol, progesterone or LH, and pregnancy achievement.