Prenatal diagnosis of carbamoyl-phosphate synthetase deficiency by fetal liver biopsy.

In a pregnancy at risk for carbamoyl-phosphate synthetase (CPS) deficiency, prenatal diagnosis was attempted by fetal liver biopsy, performed at 18 weeks of gestation. CPS activity was absent and the diagnosis was confirmed after termination of the pregnancy. The technique employed for fetal liver biopsy is described together with an evaluation of its possible role in prenatal diagnosis.