Background: A recent study reported an association between a large head circumference at birth and adult total IgE. However, no study has yet looked at the relation between head circumference and cord blood IgE.
Objectives: To assess the relationship between child's cord blood total IgE and head circumference at birth taking parental allergy and smoking habits as well as placental calcifications into account.
Methods: Two samples of unselected newborns and their mothers with uncomplicated pregnancies were studied: 235 in study A with data on parental allergy and 99 in study B with data on placental calcifications.
Results: In both studies, cord blood IgE was significantly related to large head circumference at birth (0.07 vs 0.15 IU/mL for newborns < 37 cm vs >/= 37 cm, respectively, P = 0. 03 for study A and 0.09 vs 0.28 IU/mL, P = 0.04 for study B). Cord blood IgE was unrelated to parental smoking habits. Maternal IgE significantly increased in mothers exposed to both active and passive smoking during pregnancy compared with other pregnant women. High cord blood IgE were associated with high maternal IgE (r = 0. 38; P < 0.001). Multiple linear regression showed that large head circumference, maternal IgE and clinical manifestations of maternal, but not paternal, allergy were independently related to cord blood IgE (study A). Large head circumference and placental calcifications were independently related to a higher cord blood IgE level (study B).
Conclusions: Besides the role of genetic factors, results on the preferential role of maternal vs paternal allergy and associations to large head circumference and placental calcifications support the hypothesis of the role of environmental factors during pregnancy on the level of cord blood IgE.