January 16, 2014 — Women who take certain antidepressants late in pregnancy are 2.5-times more likely to have a baby with Persistent Pulmonary Hypertension of the Newborn (PPHN), according to a new study published in the British Medical Journal.

Researchers say that the risk is highest for babies exposed to selective serotonin reuptake inhibitor (SSRI) antidepressants, such as Prozac, Zoloft, Lexapro, Celexa, and more. They estimated that the absolute risk was small:

“The absolute risk difference for development of persistent pulmonary hypertension of the newborn after exposure to SSRIs in late pregnancy was 2.9 to 3.5 per 1000 infants; therefore an estimated 286 to 351 women would need to be treated with an SSRI in late pregnancy to result in an average of one additional case of persistent pulmonary hypertension of the newborn.”

In December 2011, the U.S. Food and Drug Administration (FDA) published a warning about link between SSRI antidepressants and PPHN. Regulators said that studies were conflicting, which was a turnaround from a 2006 warning linking SSRIs to a 6-fold increased risk of PPHN.

PPHN is a severe birth defect of the lungs that causes very low oxygen levels in a baby’s blood. It occurs when blood pressure in the baby’s lungs remains high instead of dropping just before birth, which prevents blood from filling the lungs. When the baby takes its first breath, oxygen does not transfer to the blood. Babies with PPHN are at risk of severe brain damage, and about 10% of cases are fatal.