[Prognostic value of preovulatory elevations of plasma progesterone during in vitro fertilization using LHRH agonists...

We retrospectively analyzed the prevalence and prognostic significance of plasma progesterone rises during in vitro fertilization (IVF) protocols including pituitary down-regulation by LHRH agonists in a long protocol and stimulation by hMG (n = 1,116: Group A) or pure FSH (n = 178: Group B). On the day of hCG injection, plasma progesterone level was in the 0.60-0.99 ng/ml range in 7.1% of group A patients and 6.2% of group B patients (NS) and above 1 ng/ml in respectively 4.0% and 3.4% of the cases (NS). On the same day, plasma progesterone was strongly correlated with plasma estradiol (r = 0.26 - p < 0.001 in group A; r = 0.21 - p < 0.01 in group B). However, increased progesterone levels were not associated with changes in plasma LH levels, falls in plasma estradiol levels after hCG injection, or significant modifications in biological and clinical results of IVF. The cause of this pattern of progesterone rise remains to be elucidated.