Prenatal exposure to polychlorinated biphenyls and their hydroxylated metabolites is associated with motor development of three-month-old infants.

BACKGROUND

Polychlorinated biphenyls (PCBs) are ubiquitous environmental pollutants that are potentially toxic to the developing brain. Hydroxylated metabolites of PCBs (OH-PCBs) are suggested to be even more toxic. Little is known about their short-term effects on human health.

OBJECTIVES

To determine whether prenatal background exposure to PCBs and OH-PCBs was associated with the motor development of three-month-old infants.

METHODS

Ninety-seven mother-infant pairs participated in this Dutch, observational cohort study. We determined the concentrations of PCBs and OH-PCBs in cord blood samples. When the infants were three months old we evaluated their motor development by assessing the presence and performance of spontaneous movement patterns from video recordings. We calculated a Motor Optimality Score (MOS). The score could range from low (5) to high (28) optimality. We explored the correlations between PCB and OH-PCB levels and MOS. Subsequently, we tested whether the levels differed between infants with a low (<26) or high (≥26) MOS and whether the levels associated with detailed aspects of their motor repertoires.

RESULTS

We found several associations between PCB and OH-PCB levels and MOS, including detailed aspects of the early motor development. High 4-OH-PCB-107 levels were associated with a low MOS (P=.013). High PCB-187 levels were associated with reduced midline arm and leg movements (P=.047 and P=.043, respectively). High 4'-OH-PCB-172 levels were associated with more manipulation (P=.033).

CONCLUSIONS

Prenatal exposure to high background levels of most PCBs and 4-OH-PCB-107 seems to impair early motor development, whereas only 4'-OH-PCB-172 showed the opposite.