BOSTON -- Women taking anti-depressants may want to continue taking the medication when they get pregnant, according to new research from Massachusetts General Hospital.

NewsCenter 5's Heather Unruh reported Tuesday that for years, medical professionals believed the hormonal changes that come with pregnancy may help protect a woman from depression -- even for women who suffered from depression before becoming pregnant.

As a result, many doctors have advised women to stop taking their anti-depressants when they get pregnant, but new research shows that could do more harm than good.

For 20 years, Lisa Kirshenbaum has taken anti-depressants to treat her depression. But when she became pregnant five years ago, her psychiatrist advised her to stop taking the medication.

"(The doctor said) that pregnancy just created a natural high, and 'your body just adjusted' and that there was no risk, really, of depression," Kirshenbaum said.

But Kirshenbaum's depression returned, and she suffered a miscarriage. When she got pregnant a second time, she stayed on her anti-depressants and was closely watched by Massachusetts General Hospital Dr. Lee Cohen.

Cohen is the lead author of a study on depression and pregnancy.

"We followed approximately 200 pregnant women who had histories of depression and who were on anti-depressants and doing well," Cohen said.

Some of the women continued taking their anti-depressants, while others stopped entirely. The findings went against popular belief. Sixty-eight percent of the women who stopped taking the anti-depressants had their depression return, compared with 26 percent of the women who continued taking their medication.

"The widely held clinical belief over the years that pregnancy was somehow protective with respect to emotional well-being is not necessarily the case," Cohen said.

Cohen said that current research finds the most widely used anti-depressants are safe even when used early in the pregnancy. Most depression relapses occurred within the first trimester.

Kirshenbaum eventually gave birth to a healthy baby girl. She encouraged all pregnant women suffering from depression to talk to their doctors before deciding what to do about their anti-depressants.

"I don't advocate for medication. I advocate for expert advice before making decisions," Kirshenbaum said.

Cohen said that depression during pregnancy greatly increases the risk for post-partum depression, so it's very important for pregnant women to talk to their doctors about the best treatment options.