A cohort study of in utero polychlorinated biphenyl (PCB) exposures in relation to secondary sex ratio
2008

Impact of PCB Exposure on Male Birth Ratios

Sample size: 399 publication 10 minutes Evidence: moderate

Author Information

Author(s): Irva Hertz-Picciotto, Todd A Jusko, Eric J Willman, Rebecca J Baker, Jean A Keller, Stuart W Teplin, Judith M Charles

Primary Institution: University of California-Davis

Hypothesis

Does maternal exposure to polychlorinated biphenyls (PCBs) affect the secondary sex ratio of offspring?

Conclusion

Maternal exposure to PCBs may reduce the likelihood of male births.

Supporting Evidence

  • The relative risk of a male birth decreased by 33% comparing women at the 90th percentile of total PCBs with those at the 10th percentile.
  • Each 1 μg/L increase in total PCB concentration was associated with a 7% decrease in the likelihood of male births.
  • All nine PCB congeners measured showed a similar direction of association with sex ratio.

Takeaway

If moms have too much PCB in their bodies, they might have fewer baby boys.

Methodology

The study analyzed serum samples from pregnant women to assess PCB levels and their association with the sex of the infant.

Potential Biases

Selection bias may have occurred due to the sampling method.

Limitations

The study may not account for all potential confounding factors affecting sex ratio.

Participant Demographics

Participants were pregnant women from the San Francisco Bay Area during the 1960s, with a diverse socioeconomic background.

Statistical Information

P-Value

0.02

Confidence Interval

0.48–0.94

Statistical Significance

p<0.05

Digital Object Identifier (DOI)

10.1186/1476-069X-7-37

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