A Yale University School of Medicine study has revealed interesting clues that may help us to understand why synthetic estrogens, including Bisphenol-A (BPA), found in many widely-used plastics, have a detrimental effect on a developing fetus and can cause fertility problems, as well as vaginal and breast cancers.

Science Daily reports that, the study, which injected mice with diethylstilbestrol (DES)  found that synthetic estrogen alters the expression of HOXA10, a gene necessary for uterine development, and increases the risk of cancer and pregnancy complications in female offspring.

They found changes in certain regions of the HOXA10 gene. These alterations continued beyond the time of development and persisted into adulthood, indicating that exposure to DES and similar substances results in lasting genetic memory, known as “imprinting.”

“We found that HOXA 10 protein expression was shifted to the bottom portion of the uterus in the female offspring,” said Taylor. “We also found increased amounts of the enzyme responsible for changes in the DNA. Rather than just changing how much of the protein is there, DES is actually changing the structure of the HOXA 10 gene.

“These findings bring us closer to understanding the way in which DES interacts with the developing reproductive system.”

While DES is no longer available on the market the authors chose to study its effects to gain insight into how similar synthetic estrogens might work. Pregnant women are frequently exposed to synthetic estrogens, some of which have already been linked to fertility problems. The results of this study may lead to a better understanding of the risks involved.