Women with congenital heart disease: Other factors affecting labor onset and delivery mode

We read the paper “Labor onset and delivery mode in women with congenital heart disease—a nationwide cohort study,” by Sandberg et al. published in Acta Obstetricia et Gynecologica Scandinavica. We commend the authors for their remarkable efforts. This study comprehensively finds the association between maternal congenital heart diseases, labor onset, and different delivery modes.¹ While providing valuable insights, it is important to acknowledge certain concerns that merit our attention.

With the control group (n = 1 214 902) dwarfing 2425 (20.0 per 10 000) childbirths of women with mild congenital heart disease (CHD), 603 (4.9 per 10 000) of women with moderate/severe CHD, and 522 (4.3 per 10 000) of women with other CHD, such differences risk inflated statistical significance for marginal effects and reduced power to identify clinically meaningful associations in smaller groups, especially moderate/severe CHD.² Additionally, although the authors account for certain comorbidities like diabetes and hypertension, they neglected several critical factors including lifestyle choices like physical activity, obesity, and dietary factors, which can significantly influence decisions about delivery methods and their associated outcomes. This study illustrates that obesity presents an individual risk of cesarean sections and adverse maternal and neonatal outcomes,³ underscoring the importance of consideration of these elements in clinical decision-making.

Apart from the use of anticoagulants, several risk factors like uterine atony (particularly in patients with restricted use of oxytocin), placental abnormalities, uterine rupture, and obstetric trauma are worth mentioning, which may lead to misclassification of bleeding risks.³ Moreover, the lack of recognition of varying anesthetic techniques employed during labor hinders their potential impact on adverse outcomes, including the risk of postpartum bleeding.⁴ The study focuses only on the Norwegian population, which limits its generalizability due to Norway's healthcare system, characterized by universal access, high-quality care, and relatively low cesarean section rates compared to high-income countries.⁵ This setting establishes these findings as particularly relevant to Norway while engrossing us to consider their applicability in other regions.

Sandberg et al. show significant findings that highlight a compelling association between the severity of congenital heart diseases in pregnant women and the various modes of delivery. However, the need for more comprehensive research remains paramount—studies that not only consider lifestyle choices and the use of medications during pregnancy but also examine their profound impact on maternal health. These insights underscore the urgent call for broader, more inclusive studies that can inform decision-making and ultimately lead to enhanced maternal and newborn health outcomes.