A previous study identified an increased risk of persistent pulmonary hypertension of the newborn (PPHN) in mothers taking the most prescribed class of antidepressant medications in the second half of pregnancy, known as selective serotonin reuptake inhibitors (SSRIs). As a result, in 2006, the Food and Drug Administration (FDA) issued a public health advisory on a potential risk of PPHN with late-pregnancy exposure to those medications.
Now, a recent study published in The Journal of the American Medical Association (JAMA) has provided a more definitive answer to the question of whether or not SSRIs are a risk factor for PPHN. A team of researchers led by Dr. Krista F. Huybrechts from Brigham and Women’s Hospital and Harvard Medical School in Boston looked at the association between PPHN and exposure to different antidepressant medication classes late in pregnancy.
PPHN is caused by a failure in the conversion from the pattern of fetal or antenatal circulation to the “normal” pattern. Before delivery, the fetus has low blood flow in the lungs, as the fetus does not use them for oxygen transfer. Once the baby is born, there is a need for a high blood flow in the lungs for oxygen transfer. If this transition does not occur, PPHN develops.
SSRIs are often used in the treatment of major depressive disorder and anxiety disorders. Examples of SSRIs are citalopram, escitalopram, fluoxetine, paroxetine and sertraline, among others.
In the study entitled “Antidepressant Use Late in Pregnancy and Risk of Persistent Pulmonary Hypertension of the Newborn,” Dr. Huybrechts and her team looked into 3,789,330 pregnant women from the Medicaid database and compared the risk of PPHN in babies of women taking antidepressants during the 90 days before delivery to those not taking SSRIs while adjusting for confounding factors. After adjustment, the likelihood (odds) of a baby having PPHN appears to be 10% higher in mothers taking SSRIs 2% higher in mothers taking other antidepressants compared to the general population.
Although these differences were not statistically significant, this large study of publicly insured pregnant women may be consistent with a potential increased risk of PPHN with the use of SSRIs in late pregnancy. Nevertheless, the absolute risk is small, and certainly less than suggested in previous studies.