Spontaneous resolution of fetal cystic hygroma and hydrops in Turner syndrome.

On a routine ultrasound examination, a cystic hygroma and hydrops were noted at 21 weeks' gestation in a fetus with a 45,X karyotype. Serial studies demonstrated a marked reduction in the size of the cystic hygroma and complete resolution of ascites. At birth, the term infant had features characteristic of the Turner syndrome, including a webbed neck. A critical coarctation of the aorta required repair in the neonatal period. Our case provides glimpses of the intrauterine evolution of the Turner phenotype. We suggest that the possibility of survival when such lesions are detected prenatally may be greater than previously thought.