In the case of antidepressants, the answer to your question is not clear. Although it would be nice if pregnancy hormones could magically boost your mood and eliminate the need for medication, this doesn't seem to be the case. Higher rates of relapse have been found in women with a history of major depression who discontinue selective serotonin reuptake inhibitors (SSRIs) during pregnancy. One study showed that woman who stopped their medication were five times more likely to relapse during pregnancy than women who continued taking it. In this prospective study, 68 percent of the women who discontinued their SSRIs had a relapse of depression during pregnancy. Half of the women who relapsed did so in the first trimester. Therefore, if you have a history of major depression, it seems prudent to continue your antidepressants.
On the other hand, a recent report linked SSRI use in pregnancy to a higher risk of persistent pulmonary hypertension of the newborn (PPHN). This is a fairly rare condition in which the newborn's circulatory system doesn't properly adapt to changes that occur after birth, resulting in severe respiratory difficulty and requiring intensive care and treatment. A recent study showed that the risk of PPHN was up to six times higher in pregnancies in which SSRIs were used during the second half of pregnancy.
In women without exposure to SSRIs, the chance of PPHN was 2 per 1,000 births; the chance of PPHN increased to 12 per 1,000 in babies whose mothers used SSRIs after 20 weeks of gestation. Keep in mind that 99 percent of the babies exposed prenatally to SSRIs were fine, and that no increase in the risk of PPHN was found if the medications were used only in the first half of pregnancy. It's hard to balance the higher risk of maternal depression against the potential increased risk of PPHN. I recommend that you have a thorough discussion with your doctor about your particular situation in order to decide whether or not to continue taking antidepressant medication during pregnancy.
Our parenting advice is given as suggestions only. We recommend you also consult your healthcare provider, and urge you to contact them immediately if your question is urgent or about a medical condition.