In utero early suspicion of superfetation by ultrasound examination: a case report

We report the case of a dichorionic and diamniotic pregnancy with the unique feature of an early ultrasound diagnosis of a 4-week size difference, which persisted throughout pregnancy. At birth, the twins had a 1-month difference in physical and neurological maturity. We believe that only the phenomenon of a superfetation can explain this difference. We report the cases found in the literature. Copyright © 1992 International Society of Ultrasound in Obstetrics and Gynecology