Antidepressant use in pregnancy linked to newborn hypertension

Robin Wulffson MD's picture
selective serotonin re-uptake inhibitor, SSRI, pregnancy, newborn hypertension
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STOCKHOLM, SWEDEN - Antidepressant use in the U.S. has increased nearly 400% in the last two decades. According to the Centers for Disease Control and Prevention’s (CDC) National Center for Health Statistics, 11% of Americans over the age of 12 takes an antidepressant, with about 14% taking the medication for more than 10 years.

According to a new study, a widely-prescribed group of antidepressant, selective serotonin re-uptake inhibitors (SSRIs) are linked to pulmonary hypertension in newborns of mothers who took them during pregnancy. Examples of SSRIs are Lexapro, Prozac, and Paxil.

The study was published by researchers at the Karolinska Institutet in Stockholm, Sweden; it found that pregnant women who take SSRIs may be exposing their infants to the risk of risk of developing persistent pulmonary hypertension, which is a life-threatening condition that occurs in up to 2 per 1000 live-born infants. The research, which was published online in the British Medical Journal (BMJ) on January 12, was conducted by lead author Helle Kieler, MD, PhD and colleagues. They reported that infants born to women treated with SSRIs in late pregnancy had a two-fold increased risk for persistent pulmonary hypertension compared with infants born to women who did not use SSRIs.

Dr. Kieler noted, "The absolute risk was three infants per 1,000 exposed, and the increased risk seemed to be a class effect of SSRIs, as risks for the specific SSRIs––sertraline [Zoloft], citalopram [Celexa, Ciprami], paroxetine [Paxil], and fluoxetine [Prozac]––were of similar magnitude." Dr. Kieler added that an earlier study, published in 2006 in the New England Journal of Medicine by Christina D. Chambers, MD, and colleagues, reported a six-fold increased risk; however, that study did not address specific substances because the study sample was limited, with too few infants exposed to the antidepressants.

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Dr. Kieler and her team analyzed national birth registers in Denmark, Finland, Iceland, Norway, and Sweden. Their analysis included 1,618,255 single births born after 33 weeks’ gestation from 1996 to 2007. They identified 11,014 (0.7%) of the mothers who had filled a prescription for an SSRI during late pregnancy; 17,053 (1.1%) of the mothers had filled a prescription for an SSRI in early pregnancy only. Another 54,184 mothers were found to have had a previous psychiatric diagnosis but were not on any medication during their pregnancy. It is important to note that the mothers who filled a prescription were generally older and also smoked.

The researchers reported that 33 of the 11,014 infants exposed to an SSRI in late pregnancy had a diagnosis of persistent pulmonary hypertension. Of the 17,053 infants exposed only in early pregnancy, 32 gave birth to infants with persistent pulmonary hypertension. Among the mothers who had a previous psychiatric diagnosis, 114 infants had a diagnosis of persistent pulmonary hypertension of the newborn. Thus, the increased risk was 2.1 times higher for mothers who took SSRIs. In addition, there was a 40% risk for infants of women who filled a prescription with an SSRI in early pregnancy (before gestational week 8). Neither small for gestational age infants nor cesarean delivery increased the likelihood of delivering a newborn with persistent pulmonary hypertension.

Dr. Kieler noted that the mechanism whereby SSRIs cause or promote persistent pulmonary hypertension in a newborn is unknown. However, she noted, "SSRIs accumulate in the lungs… Also, considering our results suggesting a class effect for SSRIs and increased risks with other antidepressants with selectivity for serotonin and norepinephrine, one might suspect a serotonin effect. Serotonin can induce vasoconstriction and mediate pulmonary arterial smooth muscle cell proliferation." She added that for the present, physicians should tell their patients about the increased risk but also about the rarity of the disease. "We recommend caution when treating pregnant women with SSRIs and to consider nonmedical treatment for depression during pregnancy whenever possible."

Reference: British Medical Journal

Take home message:
I find it interesting that most of the women also smoked. It is an undisputed fact that smoking during pregnancy unleashes a Pandora’s Box of harmful effects on the fetus. If at all possible, women who take antidepressants should discontinue them if they are contemplating pregnancy or are pregnant. They should be continued only in cases where discontinuing them far outweighs the risk of continuing them. Smoking during pregnancy provides no benefit to the mother or her fetus—only harm.

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