Laryngeal atresia: antenatal diagnosis in a twin pregnancy.

Congenital laryngeal atresia is a rare malformation almost always incompatible with life. Prenatal sonographic diagnosis of this condition has been described on five occasions and all occurred in singleton pregnancies. To our knowledge, this is the first reported case of prenatal diagnosis of laryngeal atresia in a twin pregnancy. A monochorionic diamniotic twin gestation was noted at a routine ultrasound examination at 18 weeks' gestation. One twin was found to have changes consistent with laryngeal atresia with bilateral enlarged hyperechogenic lungs and hydrops fetalis. The other twin appeared normal. A Cesarean section was performed for worsening pre-eclampsia at 29 weeks' gestation. The abnormal twin died, despite resuscitative measures and autopsy confirmed the diagnosis of laryngeal atresia. The presence of the anomaly in only one twin of a monozygotic gestation supports the theory of a developmental anomaly within the branchial arches. Prenatal diagnosis of laryngeal atresia allows prenatal planning for resuscitation at birth, but its presence in one twin of a twin gestation poses several management dilemmas.