Ongoing pregnancy rates in intrauterine insemination are affected by late follicular-phase progesterone levels.

OBJECTIVE To determine the relationship between serum P levels on the day of hCG administration and ongoing pregnancy rates. DESIGN Retrospective study. SETTING University-affiliated private IVF. PATIENT(S) A total of 2,458 couples undergoing IUI. INTERVENTION(S) Ovarian stimulation with human recombinant FSH. MAIN OUTCOME MEASURE(S) Ongoing pregnancy and miscarriage rates. RESULT(S) Progesterone concentrations were significantly higher given that the E2 concentration increased. Ongoing pregnancy rates were significantly decreased in women with P levels higher than 1.1 ng/mL; similar results were obtained in relation to miscarriage rates. CONCLUSION(S) Significant differences in ongoing pregnancy rates when P levels were elevated on the day of hCG administration may help clinicians to counsel patients about the reduced success rates with IUI and manage the timing of insemination to optimize implantation.