Immunoglobulin and C3 levels in maternal and cord blood in Jamaica.

IgG, IgM, IgA and C3 were estimated by radial immunodiffusion (RID) in one hundred paired maternal and cord blood samples. The mean maternal IgG, and IgM, and IgA were 2112 mg/dl, 118 mg/dl and 251 mg/dl, respectively, while in corresponding infants, the mean levels were 2194 mg/dl, 36 mg/dl and 19 mg/dl. Mean cord serum C3 levels was 113 mg/dl, approximately half the maternal level (203 mg/dl). Variation in the gestational age, birth weight, duration of labour and maternal pre-eclamptic toxaemia did not significantly affect the immunoglobulin levels. Seven out of 36 (16%) cord blood with IgM level greater than 36 mg/dl showed either fourfold rise or high antibody titres against one of the TORCH (toxoplasma, rubella, cytomegalovirus and herpes simplex virus) agents. Screening of cord serum for IgM levels can be of particular value in detection of newborn infants with clinically apparent or inapparent intrauterine infections.