BOSTON (Dec. 2, 2010, 12:01 a.m. ET) Exposure to a ubiquitous environmental chemical during pregnancy may impair reproductive capacity of female offspring, according to a study published online in advance of print on December 2 in Environmental Health Perspectives. Fertility decreased over time in female mice that had been exposed during fetal and neonatal (perinatal) development to doses of bisphenol-A (BPA) that were lower than or equal to human environmental exposure levels.
"Mice exposed to BPA in the womb and during nursing subsequently had fewer successful pregnancies and delivered fewer pups over the course of the study," reported one of the study's co-senior authors, Ana M. Soto, MD, professor of anatomy and cellular biology at Tufts University School of Medicine (TUSM) and member of the cell, molecular and developmental biology program faculty at the Sackler School of Graduate Biomedical Sciences.
At the highest of three doses tested, only 60% of the BPA-exposed mice had four or more deliveries over a 32-week period, compared with 95% in the unexposed control group. Decline of the reproductive capacity of the female mice in this study was not obvious at first pregnancy, when the animals were very young, but manifested later in life with a decline in number of pups born per delivery.
"This finding is important because standard tests of reproductive toxicology currently consist of assessing the success of a first pregnancy in young animals. If subsequent pregnancies are not examined, relevant effects may be missed," said co-senior author Beverly S. Rubin, PhD, associate professor of anatomy and cellular biology at TUSM and member of the cell, molecular and developmental biology and neuroscience program faculties at the Sackler School.
"In addition, the infertility effect of BPA was dose-specific in our study. The lowest and highest doses we tested both impaired fertility, while the intermediate dose did not.
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Tufts University, Health Sciences