MONTREAL — A common chemical used in the plastic lining of frozen-food dinners and many other products is endangering the development of fetuses in pregnant women, a new study suggests.

Researchers at the Universite de Sherbrooke have shown that Bisphenol A (BPA) — an industrial chemical used in many plastics — harms stem cells in the placenta that nourish the fetus. The study is the first to focus on the impact of BPA on cytotrophoblasts, cells that attach the fetus to the uterus.

Until now, most research has been carried out on the hormone-disrupting effects of BPA on infants who drink from hard-plastic baby bottles. But the Sherbrooke study raises concerns that BPA might be causing irrevocable damage even before birth.

"Very low concentrations (of BPA) that are a hundredth of what is found in the blood of pregnant women can affect . . . the development of the fetus," said a co-author of the study, Aziz Aris.

"Research has shown that BPA is capable of easily crossing the placenta into the fetus."

The researchers collected five placentas from women who had just given birth. In the laboratory, they exposed the cells from those placentas to low concentrations of BPA for 24 hours.

The BPA ended up killing some of the cells, raising the risk of harm to the fetus.

"Our results show that doses of BPA from 0.0002 to 0.2 micrograms per millilitre, which are close to levels of BPA found in circulation of pregnant women, are cytotoxic," the study concluded.

Aris, a professor of obstetrics and gynecology, said it's safe to assume that what occurred with their lab experiments calso can take place in vivo, or in a pregnant women's body.

Aris suggested that BPA exposure during pregnancy is probably behind a growing number of miscarriages.

In the placenta, cytotrophoblasts are necessary to provide nutrients and waste exchange between the mother and her fetus. Aris said BPA causes membrane damage to the placenta.

BPA, which mimics the effects of the hormone estrogen, is used in a broad range of products. Those include toys, water pipes, drinking glasses, medical equipment, dental sealants, food-storage containers and the linings of beverage boxes and metal-based food cans.

It's even found in the filmy plastic lining in the shallow boxes of frozen-food dinners, Aris noted.

Two years ago, Canada became the first country to declare BPA hazardous to human health. In 2008, the government banned its use in baby bottles.