Relationship of follicle number, serum estradiol, and other factors to birth rate and multiparity in human menopausal gonadotropin-induced intrauterine insemination cycles.

Objective: To determine the characteristics associated with pregnancy and multiple gestation after human menopausal gonadotropin intrauterine insemination (hMG-IUI).

Design: Prospective study of all patients undergoing hMG-IUI between January 1, 1984 and December 31, 1989.

Setting: University affiliated private clinic.

Patients: Four hundred twenty-four infertility patients undergoing 779 cycles of hMG-IUI.

Main Outcome Measures: The relationship between estradiol (E2), number and size of follicles, age, and initial semen quality on pregnancy and multiple gestations in hMG-IUI cycles.

Results: The number of follicles greater than or equal to 12 mm was correlated with births and predicted all multiple births (r = 0.140, P less than 0.001). The corrected birth rate was 25.8% for age less than 35 and 14.0% for age greater than or equal to 35 when four or more follicles were greater than or equal to 12 mm. The uncorrected clinical pregnancy rate (PR) and birth rate were 12.8% and 10.5%, respectively. Decreased births were associated with tubal adhesions alone (P less than 0.03) or with endometriosis (P less than 0.002), more than four cycles of treatment (P = 0.01), initial sperm count less than 5 x 10(6) per mL (P less than 0.01), initial sperm motility less than 30% (P less than 0.002), and age greater than or equal to 35 (P less than 0.01). Estradiol was correlated with birth rate (r = 0.160, P less than 0.001), which increased from 3.6% when E2 was less than 500 pg/mL to 19.6% when E2 was greater than or equal to 2,500 pg/mL.

Conclusions: The outcome of hMG-IUI is related to the number of follicles greater than or equal to 12 mm, to E2, and to age. Optimal PRs from hMG-IUI require mild ovarian hyperstimulation.