An hypothesis for high multiple pregnancies after clomiphene.

A triplet and a quadruplet pregnancy following induction of ovulation with clomiphene are described; in each patient secondary amenorrhoea followed oral contraceptive use and several anovulatory or inadequate menstrual cycles had occurred on initial clomiphene therapy. Conception occurred in the first cycle after increasing drug dosage or the addition of human chorionic gonadotrophin (HCG) to the treatment regimen. We suggest, in explanation of these pregnancies, that repeated suboptimal stimulation of the ovaries as a result of clomiphene therapy develops several follicles to a critical stage; a subsequent greater ovulatory stimulus allows for synchronous development of several large follicles and multiple ovulation.