Previous studies have shown that
phthalate exposure in childhood is associated with the development of respiratory problems. However, few studies have assessed the relative impact of prenatal and postnatal exposure to phthalates on the development of
asthma later in childhood. Therefore, we assessed the impact of prenatal and postnatal
phthalate exposure on the development of
asthma and
wheezing using a Taiwanese birth cohort. A total of 430 pregnant women were recruited, and 171 (39.8%) of them had their children followed when they were aged 2, 5, and 8 years. The International Study of
Asthma and
Allergies in Childhood questionnaire was used to assess
asthma and
wheezing symptoms and serum total
immunoglobulin E levels were measured at 8 years of age. Urine samples were obtained from 136 women during their third trimester of pregnancy, 99 children at 2 years of age, and 110 children at 5 years. Four common
phthalate monoester metabolites in maternal and children's urine were measured using liquid chromatography-electrospray ionization-tandem mass spectrometry. Maternal urinary
mono-benzyl phthalate [MBzP] concentrations were associated with an increased occurrence of
wheezing in boys at 8 years of age (odds ratio [OR] = 4.95 (95% CI 1.08-22.63)), for upper quintile compared to the others) after controlling for parental
allergies and family members' smoking status. Urinary mono-2-ethylhexyl
phthalate [
MEHP] levels over the quintile at 2-year-old were associated with increased
asthma occurrence (adjusted OR = 6.14 (1.17-32.13)) in boys. Similarly, the sum of di-2-ethyl-hexyl
phthalate [
DEHP] metabolites at 5 years was associated with
asthma in boys (adjusted OR = 4.36 (1.01-18.86)). Urinary
MEHP in maternal and 5-year-old children urine were significantly associated with increased
IgE in allergic children at 8 years. Prenatal and postnatal exposure to
phthalate was associated with the occurrence of
asthma in children, particularly for boys.