Purpose: The natural history of certain prenatally diagnosed masses is well known. Large thoracic mass lesions can evolve one of 2 ways, either to regress and cause minimal morbidity, or to progress and enlarge, often resulting in hydropic changes in the fetus. This nonimmune hydrops carries a dismal prognosis, with nearly all fetuses expiring before or shortly after birth. However, hydrops associated with fetal mass lesions can be halted and even reversed with fetal intervention and treatment of the underlying defect. We examined our patients with fetal mass lesions to evaluate survival after intervention.
Methods: Institutional approval was obtained by the Committee on Human Research. A retrospective review was performed of 294 fetuses evaluated over 15 years with large mass lesions. All patients were evaluated for evidence of fetal hydrops using ultrasound criteria. Patients were divided according to type of intervention. Primary outcome measure was 30-day survival after birth.
Results: (1) Patients without fetal hydrops did not undergo fetal intervention and survived to 30 days after birth (167/172, 97%). (2) Patients with fetal mass lesions that developed hydrops fared poorly with no intervention (1/33 survival, 3%), whereas fetuses undergoing prenatal intervention fared much better (15/30 open, 50%; 3/10 percutaneous, 30%). (3) Four patients with hydropic congenital cystic adenomatoid malformation (n = 3) or pulmonary sequestration (n = 1) received steroids in preparation for surgery but underwent no intervention, and the patients survived the neonatal period.
Conclusion: Fetuses with prenatal diagnoses of masses not associated with hydrops have excellent prognosis with survival higher than 95%. Nonimmune hydrops associated with prenatal diagnosis of a fetal mass is a devastating complication with less than 5% survival. Open resection of a mass causing hydrops resulted in 50% survival, with reversal of hydrops in a group with near-uniform fatality. Further investigation is warranted regarding the use of minimally invasive prenatal therapies including steroid administration for hydropic fetuses.