Women who are depressed prior to pregnancy, may become even more so during pregnancy and it is known that untreated depression in pregnancy carries a six-fold increase risk of post partum depression, which can have tragic consequences for both the mother and her baby. Therefore, there are times when an antidepressant is required during pregnancy. The ideal situation is to treat the mother's depression while protecting the fetus from the possible toxic effects of a drug, so it is important to ascertain the safety of antidepressant use during pregnancy. However, studying the safety of drugs during pregnancy is not a simple task. In the absence of RCT, which is the gold standard, we have to rely on observational studies, which are usually in the form of case reports, case series, chart reviews, observational cohort studies, case-control studies, nested case-control (nested within a cohort) and days and database studies.