Immunoglobulin concentrations in newborn infants associated with intrauterine growth retardation.

Immunoglobulin G, A, and M (IgG, IgA and IgM) levels were measured in paired maternal and cord serum samples from 18 pregnancies with intrauterine growth retardation (IUGR) and 55 with normal growth (adequate-for-gestational-age pregnancies) delivered vaginally at 36 weeks' gestation or later. Cord blood levels of IgG, IgA, and IgM in IUGR infants were found significantly lower than those in infants with adequate-for-gestational-age growth. Lower Lower levels of cord IgG in IUGR may be due to a defect in the active transport of IgG across the placenta. Lower levels of cord IgM and IgA suggest an impairment of synthesis of immunoglobulins in the IUGR infants. There was no difference in cord immunoglobulin concentrations between infants with intrapartum fetal heart rate (FHR) decelerations and those without FHR decelerations in either the IUGR or the adequate-for-gestational-age group. No difference was observed in maternal immunoglobulin concentrations among the study groups.