Use of the lambda sign in fetal reduction of dizygotic triplets after intracytoplasmic sperm injection.

With the increased use of artificial reproductive technologies, there are ever greater numbers of multifetal pregnancies. The increased incidences of monozygotic twins and triplet gestations can be attributed to several factors. It is important to differentiate the chorionicity in the management of multifetal pregnancies because monochorionic gestations lead to an increased risk of prematurity, twin-to-twin transfusion, morbidity, and mortality. In a dizygotic triplet pregnancy, increased risks of obstetric complications result from the monozygotic twins, such as twin-to-twin transfusion, as well as from the presence of triplets. Fetal reduction can lower these risks. During the first trimester, a "lambda sign" on ultrasound can differentiate between monozygotic twins and a separate fetus. In this paper, we present selective fetal reduction of 1 of the monozygotic twins in order to reduce the risks resulting from either monozygotic twins or from triplets. By sacrificing 1 monozygotic twin, we believe the quality of life of the remaining babies in this case were improved.