The impact of prenatal perfluoroalkyl substances exposure on neonatal and child growth.

BACKGROUND: Perfluoroalkyl substances (PFASs) are wildly distributed environmental pollutants. Laboratory mice exposed prenatally to PFASs develop smaller birth weight but are more likely to become obese in adulthood. The evidences in human studies are still inconclusive.

METHODS: The participants were 429 mother-infant pairs from Taiwan Birth Panel Study. These children were followed serially and growth data were collected through face to face interviews and records in Child Healthcare Handbooks until 108months of age. The age-specific z-scores for weight (WAZ), length/height (LAZ/HAZ) and BMI (BMIAZ) were calculated. PFASs in umbilical cord blood were analyzed by ultra-high-performance liquid chromatography/tandem mass spectrometry.

RESULTS: At birth, perfluorooctyl sulfonate (PFOS) levels were negatively associated with weight and height [per ln unit: adjusted β (95% confidence interval, CI)=-0.14 (-0.26, -0.01) for WAZ and -0.16 (-0.31, -0.02) for LAZ]. However, these adverse impacts diminished as children grow up. When stratified the analysis by gender, the effects of prenatal PFOS exposure were more obvious for girls especially during the time span of 6 to 12 and 12 to 24months of age [per ln unit: adjusted β (95% CI)=-0.25 (-0.47, -0.04) and -0.24 (-0.41, -0.04) for WAZ, respectively; per ln unit: adjusted β (95% CI)=-0.33 (-0.59, -0.08) and -0.25 (-0.45, -0.05) for BMIAZ, respectively]. Later in the period of 60 to 108months of age, positive association between prenatal PFOS exposure and girls' BMI was observed [per ln unit: adjusted β (95% CI)=0.34 (0.007, 0.68) for BMIAZ]. There was little evidence in these data for a consistent association of perfluorooctanoic acid (PFOA) with any of the indicators.

CONCLUSIONS: Our study had shown that higher prenatal PFOS exposure was associated with decreased fetal growth, but the effects were diminished as children grow up. Modest effect of gender specific manner was observed.