Plasma Estradiol Window and Urinary Estriol Glucuronide Determinations for Monitoring Menotropin Induction of Ovulation

The plasma estradiol response is maximal 8–10 hours following menotropin injection. To obtain closer control, a menotropin protocol using 5 PM-8 PM injections and 8 AM blood sampling with a plasma estradiol window of 1000–2000 pg/ml was evaluated with simultaneous calibration of a urinary estriol glucuronide radioimmunoassay. One hundred twenty-eight paired urine and plasma samples were assayed in 48 cycles. In 26 cycles with paired samples on the day of human chorionic gonadotropin (hCG) injection, there were no cases of severe hyperstimulation, 2 cases of moderate hyperstimulation, and 11 pregnancies (42% of cycles given hCG). A window of between 40 and 100 μg/day of urinary estriol glucuronide corresponded to the 1000–2000 pg/ml plasma estradiol window by regression analysis. The pregnancy and hyperstimulation rates were compared with those observed in protocols previously published. Radioimmunoassay of urinary estriol glucuronide is faster and simpler than radioimmunoassay of plasma estradiol.