Impact of Delivery Mode on PCB and PBDE Exposure and Thyroid Hormone Levels in Newborns
Author Information
Author(s): Julie B. Herbstman, Andreas Sjödin, Benjamin J. Apelberg, Frank R. Witter, Rolf U. Halden, Donald G. Patterson Jr., Susan R. Panny, Larry L. Needham, Lynn R. Goldman
Primary Institution: Columbia Center for Children’s Environmental Health, Department of Environmental Health Sciences, Columbia Mailman School of Public Health
Hypothesis
PCBs and PBDEs alter umbilical cord blood thyroid hormone levels.
Conclusion
Prenatal PCB and PBDE exposures were associated with reduced TT4 and FT4 levels among infants born by spontaneous, unassisted vaginal delivery.
Supporting Evidence
- PCBs and PBDEs can cross the placenta and may interfere with thyroid hormone production.
- Lower levels of T4 are associated with impaired brain development.
- Infants delivered by spontaneous vaginal delivery showed significant associations with lower TT4 levels.
Takeaway
Babies born naturally may have lower thyroid hormone levels if their mothers were exposed to certain chemicals during pregnancy.
Methodology
Cord blood was collected from 297 infants, and levels of PCBs, PBDEs, and thyroid hormones were measured.
Potential Biases
Potential bias due to the exclusion of infants with maternal thyroid conditions.
Limitations
The study did not measure iodine status, which could affect thyroid hormone levels.
Participant Demographics
Median maternal age was 25 years; 72% of mothers were black, and 41% were first-time mothers.
Statistical Information
P-Value
p<0.05
Confidence Interval
95% CI for TT4 levels ranged from -4.32 to -0.24.
Statistical Significance
p<0.05
Digital Object Identifier (DOI)
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