In a study of the occurrence of detectable antibodies to SS-A and SS-B in 300 randomly selected mother-infant pairs, three (1%) mother-infant pairs were positive for precipitating antibodies to SS-A. No matched pairs were positive for SS-B. Review of the clinical history of the mother-infant pairs with SS-A antibodies failed to reveal evidence of connective tissue disease or the neonatal lupus syndrome. Follow up of two of the three SS-A positive mother-infant pairs two months after delivery also showed no evidence of disease. While the SS-A antibody may be closely associated with the development of the neonatal lupus syndrome, our study does not support the proposed aetiological nature of the antibody. Random maternal screening for possible SS-A antibody positivity and potential neonatal lupus syndrome does not appear to be warranted.