Early amniocentesis and amniotic fluid organic acid levels in the prenatal diagnosis of organic acidemias.

Organic acids were studied in amniotic fluids taken by early amniocentesis between 6 to 12 weeks in control pregnancies. The prenatal diagnosis of methylmalonic acidemia and propionic acidemia could be made by the measurement of methylmalonic and methylcitric acid respectively in the amniotic fluid taken simultaneously with chorionic villi at the 11th week of gestation.