A new mice study has found that exposure to Bisphenol A (BPA) during pregnancy leads to epigenetic changes that may cause permanent reproduction problems for female offspring.
BPA, a common component of plastics used to contain food, is a type of estrogen that is ubiquitous in the environment.
"Exposure to BPA may be harmful during pregnancy; this exposure may permanently affect the foetus," said Hugh S. Taylor, co-author of the study from Yale University School of Medicine in New Haven, Connecticut.
"We need to better identify the effects of environmental contaminants on not just crude measures such as birth defects, but also their effect in causing more subtle developmental errors," Taylor added.
Taylor and colleagues made this discovery by exposing foetal mice to BPA during pregnancy and examining gene expression and DNA in the uteruses of female foetuses.
Results showed that BPA exposure permanently affected the uterus by decreasing regulation of gene expression. These epigenetic changes caused the mice to over-respond to estrogen throughout adulthood, long after the BPA exposure.
This suggests that early exposure to BPA genetically "programmed" the uterus to be hyper-responsive to estrogen. Extreme estrogen sensitivity can lead to fertility problems, advanced puberty, altered mammary development and reproductive function, as well as a variety of hormone-related cancers.
BPA has been widely used in plastics and other materials. Examples include use in water bottles, baby bottles, epoxy resins used to coat food cans, and dental sealants.
The study has been published online in The FASEB Journal.