Experience with transvaginal ultrasound-guided aspiration of supernumerary follicles for the prevention of multiple pregnancies after ovulation induction and intrauterine insemination.

Objective: To avoid multiple pregnancies caused by ovulation induction.

Setting: Infertile couples treated in the Women's Hospital and the Institute of Reproductive Medicine of the University of Münster, Münster, Germany.

Design: The outcome of ovulation induction in patients in whom supernumerary ovarian follicles were aspirated transvaginally was compared with the outcome in patients in whom this intervention was not necessary. In a second randomized prospective study, the efficacy of a low dosage of gonadotropins was compared with a higher dosage.

Patients: Two hundred twenty-seven couples suffering from male infertility, unexplained infertility, incipient ovarian failure, and polycystic ovaries.

Interventions: Aspirations were performed if more than three follicles were sized > 14 mm.

Main Outcome Measure: Number of (multiple) pregnancies.

Results: During 232 ovulation inductions, 127 aspirations of supernumerary follicles were performed (54.7%). The pregnancy rate (PR) in these cycles was similar to cycles in which aspirations were unnecessary (24.4% versus 21.9%). The efficacy of 75 units of FSH administered daily during the recruitment phase of follicular development was equivalent to 150 units of FSH (PR: 32.4% versus 31.6%), but supernumerary follicles were fewer (26.5% versus 76.3%). Six twins, two triplets (multiple PR: 10.4%), and no ovarian hyperstimulation syndrome occurred.

Conclusions: Transvaginal aspiration of supernumerary follicles does not reduce the PR in ovulation induction. Supernumerary follicles can be avoided by low-dose administration of gonadotropins without compromising the PR.