Recent studies have shown that the use of Paxil during pregnancy increases the chances of birth defects. In December 2005, the Food and Drug Administration moved Paxil from a class C drug to a class D drug. A class C drug is one that has been proven to harm animals; and a class D drug is one that has been proven to harm the human fetus. According to the FDA, a Swedish study was done which proved that women who took Paxil in the first trimester (first twelve weeks) of the pregnancy had two times higher risk in having a baby with some form of birth defect than other women who took another form of antidepressant or non antidepressant medication.