Risk factors for high-order multiple pregnancy and multiple birth after controlled ovarian hyperstimulation: results of 4,062 intrauterine insemination cycles

Objective: To determine factors responsible for high-order multiple pregnancy (HOMP) and high-order multiple births when multiple cycles of controlled ovarian hyperstimulation-IUI (COH-IUI), are performed. Design: Retrospective analysis. Setting: Private infertility clinic. Patient(s): Women (n = 2,272) who underwent 4,067 consecutive COH-IUI cycles. Intervention(s): None. Main Outcome Measure(s): High-order multiple pregnancy rate, pregnancy rate (PR), and birth rate (PR) per rat cycle. Result(s): High-order multiple pregnancy was related to number of follicles of diameter >= 10 mm, age, and treatment cycle. For age < 32 years, HOMP was 6% for three to six follicles and 20% for seven or more follicles. For ages 32 to 37 years, HOMP was 5% for three to six follicles and 12% for seven or more follicles. In the first COH-IUI cycle, HOMP was 8% for three to six follicles and 15% for seven or more follicles. In the second cycle, HOMP did not occur unless there were more than six follicles. No HOMP occurred after the second cycle. Pregnancy rate did not increase significantly when there were more than four follicles. Continuing COH-IUI past the third cycle resulted in additional pregnancies in patients with one to eight, follicles. Conclusion(s): High-order multiple pregnancy can be predicted by age and number of follicles of diameter >= 10 min. Controlled ovarian hyperstimulation is not necessary to achieve satisfactory overall pregnancy rates if ovulation induction is continued past the third cycle in low responders. (c) 2005 by American Society for Reproductive Medicine).