Risk of Stillbirth and Preterm Birth in Cardiac Arrhythmias During Pregnancy

The incidence of arrhythmias among pregnant women has increased over the past decade. While the spotlight intensifies on managing these rhythms, national-level data assessing the risk of stillbirth and preterm birth in this population is limited.

This study aimed to assess the risk of stillbirth and preterm birth among pregnant women admitted with arrhythmias.

The authors used the Nationwide Readmissions Database and included all pregnant women with cardiac tachyarrhythmias (atrial fibrillation/flutter [AF], ventricular arrhythmias [VA], and supraventricular tachycardia [SVT]) (2017-2020). We compared the risk of stillbirth and preterm birth between pregnant women with cardiac arrhythmias and those without, identified through ICD-10-CM codes. Propensity score matching was performed, followed by multivariate analysis to analyze the association of cardiac tachyarrhythmias with stillbirth and preterm birth.

The authors identified 7,517,975 pregnant women: 11,091 (0.2%) had cardiac tachyarrhythmias. Among them, 7,503 (67.6%) had SVT, 2,340 (21.1%) had AF, and 906 (8.2%) had VA. The prevalence of cardiac arrhythmias, including SVT and VA subtypes, increased significantly during the study period. There was a nonsignificant upward trend in stillbirth incidence among patients with tachyarrhythmias, whereas a nonsignificant downward trend was observed in those without tachyarrhythmias. Multivariate analysis showed that patients with VA had significantly higher odds of stillbirth (adjusted OR [aOR]: 3.83; 95% CI: 1.21-12.12; P = 0.02) compared with those without arrhythmias. However, SVT and AF were not associated with higher odds of stillbirth than those without arrhythmias (aOR: 1.32; 95% CI: 0.77-2.28; P = 0.32 and aOR: 1.15; 95% CI: 0.51-2.59; P = 0.74). Patients with VA, AF, and SVT were associated with significantly higher odds of preterm birth compared with those without arrhythmias (VA aOR: 2.01; 95% CI: 1.56-2.60; P < 0.01; AF aOR: 1.63; 95% CI: 1.38-1.93; P < 0.01; SVT aOR: 1.19; 95% CI: 1.07-1.32; P < 0.01). Of those with tachyarrhythmias, 36 patients (0.5%) with SVT and 60 patients (2.6%) with AF underwent cardioversion. Seventeen patients (1.9%) with VA had defibrillation. Further analysis showed that patients with tachyarrhythmias who underwent cardioversion/defibrillation were not associated with higher odds of stillbirth (aOR: 2.62; 95% CI: 0.10-66.95; P = 0.56) or preterm birth (aOR: 1.82; 95% CI: 0.98-3.40; P = 0.06) compared with those who did not undergo these procedures.

The overall prevalence of cardiac tachyarrhythmias in pregnant women was low (0.2%) but has significantly increased in recent years. Compared with those without tachyarrhythmias, VA was significantly associated with higher odds of stillbirth, whereas SVT and AF were not. All tachyarrhythmia subtypes were associated with higher odds of preterm birth. Cardioversion/defibrillation might not be associated with higher odds of stillbirth and preterm birth.