Prognosis in fetal cystic hygroma.

Axillary and lateral cervical fetal cystic hygromas in a fetus with normal karyotype are described. Fetal death at 25 weeks' gestation occurred. A literature review revealed that for cystic hygroma 42% of infants are 45XO, 38% have a normal karyotype, and 18% have trisomies. Prognosis is grim if the karyotype is abnormal or if hydrops or bilateral pleural effusions are present. Survival rate progressively improves with normal karyotype (27%), unilateral pleural effusion (40%), atypical location (56%), and resolution of cystic hygroma (71%). No single feature signifies 100% survival. The overall survival rate for fetal cystic hygroma is 10%. Prognosis remains guarded regardless of all other factors until the fetus reaches 26 weeks' gestation, after which time a 67% chance of ultimate survival can be expected. Only 42% of documented survivors were completely normal at follow-up.