The inability of preovulatory ovarian scan to predict multifetal pregnancy occurrence in a follow-up of induction of ovulation with menotropins

Objective: To establish the predictive role of preovulatory ovarian ultrasonography in the occurrence of multiple pregnancy after hMG and hCG treatment for anovulatory infertility. Design: Prospective. Setting: Outpatient Infertility Clinic. Patients: Ninety-five anovulatory women who conceived after gonadotropin therapy. Intervention: Induction of ovulation by hMG and hCG monitored by plasma E₂ measurements and ovarian ultrasonography. Main Outcome Measures: All follicles visualized on the day of hCG administration were recorded and divided into the following four groups: group I, 10 to 12 mm; group II, 13 to 15 mm; group III, 16 to 18 mm; and group IV, 19 mm and larger. The sonographic findings were statistically evaluated to 80 singletons and 45 multiple pregnancies. Results: No statistical correlation was found to exist between the number of follicles from the different groups and the number of fetuses. Conclusions: The number and sizes of follicles visualized on the day of hCG administration have no predictive value regarding the occurrence of a multiple pregnancy.