Prenatal phthalate exposure linked to low birthweight

Prenatal exposure to phthalates, a common chemical ingredient in cosmetics and personal care products, increases the risk of an infant being born with low birthweight (LBW), according to a study published online June 25 in the Journal of Pediatrics.

Yunhui Zhang, PhD, of Fudan University in Shanghai, China, and colleagues enrolled a study group of LBW mother-infant pairs and a normal birthweight control group, who lived in Shanghai from 2005 to 2006. Specimens of maternal blood, umbilical cord blood, and meconium were tested for phthalates using liquid chromatography-mass spectrometry. Associations between phthalate exposure and LBW were estimated using conditional logistic regression.

The researchers detected phthalates in more than 70% of the blood and biosamples examined. Higher phthalates levels were found in the mothers with LBW infants than in the control group, the risk varying by the amount and type of phthalates present. After making adjustments for potential confounders, those with the highest quartile di-n-butyl phthalate (DBP) and di-2-ethylhexyl phthalate (DEHP) concentrations were associated with increased LBW risk (odds ratios, 3.54 and 1.19, respectively). DEHP also was associated negatively with birth length.

“Newborns in China are ubiquitously exposed to phthalates; significantly higher phthalate levels were detected in LBW cases compared with controls. In utero DBP and DEHP exposures were associated with LBW in a dose-dependent manner. Prenatal phthalate exposure may be a risk factor for LBW,” the authors conclude.

Zhang Y, Lin L, Cao Y, et al. Phthalate levels and low birth weight: A nested case-control study of Chinese newborns. J Pediatr. doi:10.1016/j.jpeds.2009.04.007.