Prenatal phthalate exposure and early childhood wheeze in the SELMA study

Background Prenatal maternal phthalate exposure has been associated with wheeze and asthma in children, but results are inconclusive. Previous studies typically assessed exposure in late pregnancy, included only a small number of old phthalates, and assessed outcomes in children aged 5 years or older. Objective We explored associations between 1st trimester prenatal maternal exposure to a wider range of phthalates and wheeze in early childhood. Methods First trimester concentrations of 14 metabolites from 8 phthalates and one alternative plasticizer were quantified in first-morning void urine from 1148 mothers in the Swedish SELMA study. Associations between log-transformed metabolite concentrations and parental reported ever wheeze among 24-month-old children were investigated with logistic regression models adjusted for parental asthma/rhinitis, sex of child, maternal education, smoking, and creatinine. Results Metabolites of replacement phthalates di-iso-decyl phthalate (DiDP) and di-2-propylheptyl phthalate (DPHP) were associated with increased risk for wheeze (aOR 1.47, 95% CI 1.08-2.01 and aOR 1.49, 95% CI 1.04-2.15, respectively). The associations with DiDP and DPHP were stronger among children whose parents did not have asthma or rhinitis. In this group, wheeze was also associated with metabolites of butyl-benzyl phthalate (BBzP) and di-iso-nonyl phthalate (DiNP). Significance Maternal phthalate exposure during early pregnancy may be a risk factor for wheeze in early childhood, especially among children whose parents do not have asthma or rhinitis symptoms.

Automated summary

The study suggests that maternal phthalate exposure during early pregnancy may increase the risk of wheeze in early childhood, especially among children whose parents do not have asthma or rhinitis symptoms. Associations were found with metabolites of replacement phthalates DiDP and DPHP, as well as BBzP and DiNP in this group.