Polyhydramnios, fetal overgrowth, and macrocephaly: Prenatal ultrasound findings of Costello syndrome

Costello syndrome is a multiple congenital anomaly syndrome consisting of dysmorphic facies, cutis laxa, short stature, developmental delay, and mental retardation. Complications include failure to thrive, hypertrophic cardiomyopathy with arrhythmias, and benign and malignant tumors. This report describes a new case of Costello syndrome in a preterm infant born at 27 weeks gestation and diagnosed with Costello syndrome at 7 weeks of life who died at 6 months of age due to cardiac and pulmonary complications. In addition, data were compiled from parent surveys including growth parameters on 16 infants who were subsequently diagnosed with Costello syndrome and had mutation confirmation. The most common prenatal findings in the literature and in this cohort were polyhydramnios and fetal overgrowth with relative macrocephaly. Based on this study, ultrasound identification of polyhydramnios in the context of prenatal overgrowth, especially with relative macrocephaly, needs to raise the possibility of a diagnosis of Costello syndrome in the fetus because of the life-threatening cardiac complications that may occur early in the newborn period.