But Reefhuis said these risks are so small to begin with that modest increases would be nearly insignificant. "For the three defects we discussed, they're pretty rare -- so even quadrupling the risk still leads to a less than 1 percent risk that the mother would have a child with one of these birth defects," she said.
The absolute risk of getting these diseases was so small that further investigations would be necessary to confirm that the links did not show up due to chance alone. Another study conducted by researchers at Boston University and Harvard University, also published in New England Journal of Medicine this week, looked at the same three birth defects, among others, and found no overall connection between SSRIs and these maladies.
"It's a fairly reassuring article," said Dr. Jennifer Niebyl, head of obstetrics and gynecology at the University of Iowa. "The numbers are sufficiently small that you can't say that this is cause and effect."
Women's mental health expert Stowe agrees that this is good news, but says it is not the end of the story. "Reassuring studies, but it's only one piece of the picture," said Stowe. "Just because the medicine doesn't cause birth defects, that's one side of the coin; what about any long-term effects?"
For this reason, he said, more research is needed before the drugs can be declared completely harmless to unborn babies.
"So far, most of the studies with antidepressants have been pretty good, but there haven't been that many done," Stowe said. "I'm glad they're not finding birth defects, but I don't want studies like this to greenlight wholesale prescribing of these medicines to anyone."
That is a message Reefhuis and her colleagues hope women and their doctors will take to heart. "I think it's really important that women talk to their health care provider to discuss their individual situation," she said, adding that she hopes women and their physicians will work together "to come up with the best possible course of action for that specific woman."