Guidelines and consensus: statement on pregnancy in pulmonary hypertension from the Pulmonary Vascular Research Institute.

Abstract

Editor: We read with interest the 2015 Statement on Pregnancy in Pulmonary Hypertension from the Pulmonary Vascular Research Institute.1 It aimed to provide evidence-based guidelines for the management of pregnancies complicated by pulmonary hypertension. Specifically, the authors staunchly recommend cesarean delivery between 34 and 36 weeks gestation as the preferred mode of delivery. The authors assert that cesarean delivery “bypasses the hemodynamic complications associated with labor… and also the auto transfusion associated with vaginal contractions.” p45 We find fault with both this recommendation and its justification, and we are troubled that the authors obtained limited obstetric input (only 1 of the 9 authors was affiliated with a department of obstetrics) and did not utilize specialty and interdisciplinary working groups when drafting pregnancy-related guidelines. We assert that route and timing of delivery in the setting of pulmonary hypertension complicating pregnancy remains controversial. Although recent management trends favor planned cesarean delivery, there is little evidence that cesarean delivery improves maternal outcomes over vaginal delivery.2,3 Although cardiac output can increase by up to 25% in active labor and by 50% during maternal pushing efforts, assisted second-stage labor and laboring in the lateral decubitus position can both greatly offset these changes.4 Moreover, cardiac output in the postpartum period can increase by as much as 80% regardless of delivery route. It is also relevant to consider that induction of regional anesthesia for cesarean delivery can result in hypotension in up to 30% of cases.4 Overall, cesarean delivery results in higher rates of severe maternal morbidity and mortality, including higher rates of death, hemorrhage, shock, cardiac arrest, renal failure, venous thromboembolic event, and infection.5 Both the severity of pulmonary disease and the woman's pregnancy history must be considered in any delivery recommendation. A woman with mild, stable pulmonary hypertension is very different from one with severe right ventricular failure requiring, for example, parenteral prostanoid or nitric oxide therapy. Likewise, an urgent cesarean delivery involving a multiparous woman presenting in rapidly progressive labor can cause more harm than vaginal delivery. Successful management of the gravid woman with pulmonary hypertension requires a multidisciplinary team comprising individuals from obstetrics, anesthesiology, and neonatology departments, as well as a pulmonary hypertension specialist, working with experienced support staff. We advocate for an individualized delivery plan taking relevant maternal and pregnancy characteristics into consideration.