Maternal testosterone in pregnancy and atopic outcomes in childhood

Background:  In mice, androgens downregulate Th2 cytokine responses, but whether androgen levels during pregnancy might influence the development of allergy in the offspring has not been studied. Methods:  In the Avon Longitudinal Study of Parents and Children (ALSPAC), a population-based birth cohort of 14 541 pregnancies, we related maternal blood total testosterone during pregnancy, measured in a subset of the cohort, to allergic outcomes in the offspring, including asthma, hayfever, eczema (n = 543) and wheezing (n = 532) at 69–81 months, and atopy (positive skin prick test to Dermatophagoides pteronyssinus, cat or grass, n = 386) and blood total immunoglobulin E (IgE; n = 314) at 7 years. We used logistic and linear regression to analyse binary outcomes and log-transformed IgE, respectively, controlling for potential confounders. Results:  Maternal testosterone was negatively associated with total IgE in boys [adjusted geometric mean ratio (GMR), per doubling of testosterone, 0.33 (0.20–0.55), P = 0.000038 (n = 168)], but not in girls [GMR 1.04 (0.53–2.06), P = 0.91 (n = 146)], P-value interaction 0.0086. The effect in boys was even stronger in the absence of maternal atopic disease. Testosterone was not associated with skin test positivity or atopic disease in either sex. Conclusions:  Higher testosterone levels in pregnancy are associated with lower IgE production in boys.