The demonstrated teratogenicity of maternal zinc deficiency in rats has led to burgeoning interest in zinc and other trace elements as important factors in embryonic development. Levels of zinc, copper, manganese, magnesium, folic acid, vitamin B12 and vitamin A were evaluated at the beginning of pregnancy in the plasma of pregnant women who later delivered a malformed newborn. Fetal chromosomal anomalies and recognizable nonchromosomal syndromes were excluded. The results were compared to control women who delivered normal babies. One hundred seventy mothers had malformed children. The more frequent congenital malformations were congenital heart diseases (72 cases including 24 VSD), musculoskeletal malformations (21 cases), urogenital malformations (23 cases), spina bifida (6 cases), hydrocephaly (6 cases), and labial cleft (14 cases). Maternal plasma concentrations of zinc, copper, magnesium, manganese, folate, vitamin B12, and vitamin A of malformed children did not differ from controls. Thus vitamin profiles do not form a suitable means for identifying women at risk for having a child with congenital malformations.