A new study has determined that taking antidepressants during the first trimester of pregnancy does not increase the risk of heart defects in a developing fetus, despite an existing study that showed the practice could be dangerous.

According to the U.S. Centers for Disease Control and Prevention (CDC), many women suffer from depression during, and even after, pregnancy. A national survey revealed that 11 percent of pregnant women experienced major depression in 2012.

Krista Huybrechts, lead author of the study and epidemiologist at Brigham and Women's Hospital, and her colleagues looked at the data related to 949,504 pregnant women to determine whether there was a direct relationship between antidepressants and heart defects. The women were previous participants of a nationwide Medicaid study between 2000 and 2007.

"The most critical period in the development of an embryo or in the growth of a particular organ is during the time of most rapid cell division. So it is in the first three months of pregnancy that the risk for developing major malformations is highest," Huybrechts told Healthday News.

The researchers found that 6.8 percent, or about 65,000 of the study's pregnant women, took antidepressants during the first three months of their pregnancy; of this figure, there were about 580 infants born with heart defects as opposed to the 6,403 infants born with heart defects from mothers who did not take antidepressants.

The study concluded that taking antidepressants did not increase the risk of heart defects in infants. Nevertheless, at least one expert has argued that it contained serious flaws.

"This isn't rocket science. We know that exposing developing babies to synthetic chemicals is almost always a really bad idea and should be avoided whenever possible," said Dr. Adam Urato, a maternal-fetal medicine specialist at Tufts Medical Center in Boston, to Healthday News. "This study does nothing to alter that common sense conclusion."

Pregnancy-related depression can be treated using talk therapy or by taking antidepressants. Leaving depression untreated could result in complications such as low birth-weight or premature birth.  

Details of the study were published in the June 19 issue of the New England Journal of Medicine.