Effects Of Prenatal Phthalate Exposure Research Articles

Background and Aims: Epidemiologic evidence suggests that effects of prenatal phthalate exposure on child executive function and behavior are sexually dimorphic. We reported (ISEE 2010) adverse associations between prenatal phthalate concentrations and child age 3 mental, motor and behavioral development. Here we evaluate whether the associations varied by child sex. Methods: 168 girls and 151 boys from inner-city communities in New York City were followed from pregnancy. Mono-n-butyl phthalate (MnBP), mono-benzyl phthalate (MBzP), and mono-isobutyl phthalate (MiBP) concentrations were measured in spot urine collected from the mothers during the 3rd trimester. At child age 3 years, mental and motor development were assessed using the Bayley Scales of Infant Development II and behavior problems was assessed by maternal report on the Child Behavior Checklist (1 ½ -5). Results: Controlling for specific gravity and potential confounders, logeMnBP concentrations were significantly associated with motor development among boys only (adjusted estimated B= -3.1 [95% CI -5.8, -0.3]) and with mental development among girls only (B=-2.6 [95%CI -4.6, -0.6]). The child sex-by-MnBP interaction on risk of mental delay was significant (p=0.04). Among boys only, logeMnBP concentrations were associated with significant increases in emotionally reactive behavior (p=0.005), somatic complaints (p=0.007), withdrawn behavior (p=0.02) and internalizing behaviors (p=0.006). Child sex-by-MnBP interaction on emotionally reactive behavior was significant (p=0.03) and on somatic complaints was of borderline significance (p=0.059). Among girls only, logeMBzP concentrations were associated with significant increases in anxious/depressed behavior (p=0.004), somatic complaints (p=0.01), withdrawn behavior (p=0.0003) and internalizing behaviors (p=0.0001). Child sex-by-MBzP interaction on withdrawn behavior was of borderline significance (p=0.054). Conclusions: Associations between prenatal exposure to these phthalates and child mental, motor and behavioral development appear to vary by child sex.