The status of prenatal diagnosis and fetal surgery

Abstract

The last two decades have witnessed the revolutionary development and clinical application of several techniques for prenatal diagnosis of fetal abnormalities. Amniocentesis has helped to establish the diagnosis of major chromosomal and inherited metabolic disorders. Sonography has identified congenital malformations incompatible with life and has permitted the early diagnosis of correctable congenital malformations. Antenatal knowledge of these abnormalities can potentially decrease neonatal morbidity and mortality because the appropriate preparations can be made in advance of the delivery. The International Fetal Surgery Registry of 1985 reported 73 cases of fetal obstructive uropathy treated by in utero placement of a chronic vesico-amniotic shunt. No relationship could be demonstrated between survival and amniotic fluid volume or fetal age at diagnosis or treatment. Twenty-seven of 29 deaths were reportedly due to pulmonary hypoplasia. The data strongly suggests the need to develop a test that evaluates fetal pulmonary status. The registry data on 41 cases of hydrocephalic fetal decompression were reviewed. Survival was 83%, however 54% of cases survived with a moderate to severe handicap. No relationship between duration of shunt placement and outcome could be determined. The outcome data was difficult to interpret. No conclusions were made or implied concerning whether or not these fetuses were actually benefited by the procedure. Fetal surgery can be performed with an acceptable procedure —related mortality and morbidity. As of this date, we can not conclude that in utero fetal surgery has improved survivor morbidity. The registry data points to the need for controls and for a properly designed prospective study.