Re: Selective serotonin reuptake inhibitors during pregnancy and risk of persistent pulmonary hypertension in the newborn: population based cohort study from the five Nordic countries
Despite finding a difference in persistent pulmonary hypertension in the newborn between babies born to mothers with and without SSRI prescriptions it was disappointing that the authors could not postulate a mechanism for this. Persistent pulmonary hypertension of the newborn is thought to result from the failure of the normal fetal-to-neonatal circulatory transition, normally initiated by labour and birth. Previous case-control work showed that the risk is higher for those infants born by cesarean section (CS)(1). Other respondants have drawn attention to missing items from the modelling. In view of the striking difference in CS rate in the exposed and unexposed infants (19.0 vs 13.7%), it was disappointing to see that both gestational age and the vital issue of labour were not analysed as these are normally key obstetric predictors of outcome. Prelabour CS has profound effects on the infant, partly as it precludes the neonate initiating labour and being matured by it (2). Anxiety and depression leading to increased rates of prelabour CS might be the common explanation for the current finding of a link with SSRI use and persistant pulmonary hypertension, yet this conclusion cannot be excluded by the methodology used.
1. Hernández-Díaz S, Van Marter LJ, Werler MM, Louik C, Mitchell AA. Risk Factors for Persistent Pulmonary Hypertension of the Newborn Pediatrics 2007;120(2):e272 -e282
2. Hyde M, Mostyn A, Modi N, Kemp PR. The health implications of birth by Caesarean section. Biol Rev 2011;87(1):229-43
Competing interests: No competing interests