[A case of a dizygotic twin pregnancy where superfetation seems indisputable].

A case of superfoetation is presented. Difference of age (3 weeks) between twins was established by ultrasound at 10 weeks, and persisted through subsequent echographic surveillance up to delivery at 39 of amenorrhea with twin 39 and 36 weeks old. Only three publications in recent international literature are related to superfoetation. An attempt is made to try to understand superfoetation and to clearly differentiate it from superovulation.