Recurrent twin pregnancy, with the second a heterotopic pregnancy, following clomiphene citrate stimulation: an unusual case and a review of the literature.

Multiple gestations are on the rise with the advent of artificial reproductive technologies. Even with ovulation induction using clomiphene citrate alone, the twinning rate can reach up to 9 percent. We report a case of recurrent twin gestation after treatment with clomiphene citrate, with the second pregnancy being heterotopic. We also review, using Medline and PubMed, previously reported cases of recurrent twin gestation after treatment with clomiphene citrate published before June 2014. Patients undergoing ovulation induction for oligoovulation, anovulation, or unexplained infertility should always be counseled about the possibility of multiple gestation prior to the treatment including the probability, although low, of a heterotopic pregnancy.