Pregnancy rates in donors versus recipients according to the serum progesterone level at the time of human chorionic gonadotropin in a shared oocyte program.

Previous data suggested a subtle increase in serum P at the time of hCG injection without LH surge reduces the PR of women having oocyte retrievals for IVF; this study compared PRs of recipients in a shared oocyte program according to the donors' pre-hCG P level. There was no difference in viable PRs between recipients and donors when P < or = 1 ng/mL. The PR was similar for recipients when donors' P was > 1 ng/mL (12.7%). Donors with P > 1 ng/mL had the lowest PR: 7.2%. The data suggest that the adverse effect of higher serum P without LH surge may be on the endometrium rather than the oocyte.