MONDAY, Oct. 14 (HealthDay News) -- Two plastics chemicals -- bisphenol A (BPA) and phthalates -- may reduce the reproductive ability of both men and women, according to a new pair of small, early studies.

Women with high levels of BPA in their blood have an 80 percent increased risk of miscarriage when compared to women with little or no BPA, reported study co-author Dr. Ruth Lathi.

"BPA at time of conception was significantly higher in those who miscarried compared to those who had a live birth," said Lathi, an assistant professor of obstetrics and gynecology at the Stanford University Medical Center, in Palo Alto, Calif.

Meanwhile, couples can experience a 20 percent reduction in their reproductive capability if the male partner has high phthalate concentrations, according to a study funded by the U.S. National Institute of Child Health and Human Development.

Both studies were scheduled for presentation this week at the joint meeting of the International Federation of Fertility Societies and the American Society for Reproductive Medicine, held in Boston.

The pair of studies should add to growing concerns over the effect of environmental chemicals on reproduction, birth outcomes and early childhood development, said Dr. Linda Giudice, president of the American Society for Reproductive Medicine.

"It's important we don't scare people," Giudice said. "The aim is to inform people to minimize risk and maximize health."

However, a representative from the trade group American Chemistry Council (ACC) disputed the associations claimed by the researchers.

"These studies both appear to be small-scale studies that cannot establish any cause-and-effect relationship," said ACC spokeswoman Kathryn Murray St. John. "They are based on single samples to monitor exposure and so it is difficult to draw any meaningful conclusions."

BPA and phthalates are chemicals used in the production of plastics. Phthalates are no longer used to make baby products such as teething rings and pacifiers, and BPA has been banned for use in sippy cups, baby bottles and infant formula packaging.

Some doctors are concerned that the chemicals disrupt the function of hormones in the human body and could have harmful effects on unborn children.