A few weeks after the FDA called into question the association between SSRI exposure and persistent pulmonary hypertension of the newborn or PPHN, BMJ published another article supporting an increased risk of PPHN among infants exposed to SSRIs in utero.
This large study is similar to the studies published by Kallen and colleagues using the Swedish Birth Registry. What makes the BMJ study different is its size. Combining the birth registries of four countries (Sweden, Norway, Finland, Iceland and Denmark), they were able to look at the birth records of over 1.6 million women. Here is a summary of the findings:
- SSRI exposure in late pregnancy was associated with an increased risk of PPHN, with an absolute risk of 3 per 1000 infants compared with the background incidence of 1.2 per 1000 (adjusted odds ratio [OR] of 2.1).
- Risk of PPHN was similar for each of the SSRIs studied (sertraline, citalopram, paroxetine, and fluoxetine), with ORs ranging from 2 to 3.
- There was a slightly increased risk of PPHN for those women who filled a prescription for an SSRI before gestational week 8 (adjusted OR 1.4).
As in previous studies, there are significant limitations to this study. While women filled prescriptions for SSRIs, it is not clear if they were actually were these medications regularly. In addition, it may be difficult to distinguish whether increased risk of PPHN is the result of medication exposure versus a result of the depression. (Interestingly, there was a small increase in risk of PPHN among women who were previously psychiatrically hospitalized but took no medications during pregnancy.)
So will this study change how we make recommendations regarding the use of SSRIs in pregnancy? Probably not. The authors note that despite the large number of included births, only 33 infants exposed to an SSRI in late pregnancy were diagnosed with PPHN. The absolute risk is therefore quite low, about 0.3%.
Ruta Nonacs, MD PhD
Kieler H, Artama M, et al. Selective serotonin reuptake inhibitors during pregnancy and risk of persistent pulmonary hypertension in the newborn: population based cohort study from the five Nordic countries. BMJ 2012; 344:d8012.
Perspective – Reevaluating the Risk for PPHN in Clinical Psychiatry News