WEDNESDAY, June 12 (HealthDay News) -- A pregnant woman's exposure to environmental contaminants affects her unborn baby's heart rate and movement, a new study says.
"Both fetal motor activity and heart rate reveal how the fetus is maturing and give us a way to evaluate how exposures may be affecting the developing nervous system," study lead author Janet DiPietro, associate dean for research at the Johns Hopkins Bloomberg School of Public Health, said in a school news release.
The researchers analyzed blood samples from 50 high- and low-income pregnant women in and around Baltimore and found that they all had detectable levels of organochlorines, including DDT, PCBs and other pesticides that have been banned in the United States for more than 30 years.
High-income women had a greater concentration of chemicals than low-income women.
The blood samples were collected at 36 weeks of pregnancy, and measurements of fetal heart rate and movement also were taken at that time, according to the study, which was published online in the Journal of Exposure Science and Environmental Epidemiology.
The researchers found that higher levels of some common environmental pollutants were associated with more frequent and vigorous fetal movement. Some of the chemicals also were associated with fewer changes in fetal heart rate, which normally parallel fetal movements.
"Most studies of environmental contaminants and child development wait until children are much older to evaluate effects of things the mother may have been exposed to during pregnancy," DiPietro said. "Here we have observed effects in utero."
How the prenatal period sets the stage for later child development is a subject of tremendous interest, DiPietro said.
"These results show that the developing fetus is susceptible to environmental exposures and that we can detect this by measuring fetal neurobehavior," she said. "This is yet more evidence for the need to protect the vulnerable developing brain from effects of environmental contaminants both before and after birth."
The MedlinePlus Medical Encyclopedia has more about fetal development.
SOURCE: Johns Hopkins Bloomberg School of Public Health, news release, June 11, 2013