Maternal hypertensive disorders of pregnancy and electrocardiographic findings in newborns

Abstract

Abstract Background Hypertensive disorders of pregnancy (HDP) - preeclampsia in particular - are important causes of pregnancy complications and death for both the mother and her offspring. Preeclampsia is also associated with both congenital heart defects (CHDs) in the offspring and subtle changes in left ventricular structure and function in the offspring. However, whether preeclampsia also affects the newborn’s cardiac conduction system is unknown. Purpose To assess whether newborns born after pregnancies complicated by HDP exhibit changes in their electrocardiogram (ECG) compared with newborns born after pregnancies without HDP. Methods This population-based cohort study included newborns, who had ECG data obtained within 30 days of birth. Information on maternal preeclampsia (ICD-10 codes DO14-14.2 and DO15-15.9) and maternal gestational hypertension (ICD-10 codes DO13-13.9) was retrieved from an obstetric database. ECG parameters of interest included heart rate, PR interval, QRS axis, QRS duration, uncorrected and corrected QT intervals, maximum R- and S-wave amplitudes in V1 and V6, respectively. ECG parameters of exposed and non-exposed newborns were compared using summary statistics and linear regression, adjusting for sex, gestational age at delivery and length, weight and age at examination. Sensitivity analyses were conducted with adjustments for maternal smoking, parity, age, and multiple pregnancies and the analyses were repeated after excluding neonates and mothers with CHD, newborns exposed to pre-gestational diabetes and children born preterm (<37 weeks’ gestation). Results Our study cohort included 11,826 newborns; 441 were exposed to maternal preeclampsia and 320 were exposed to maternal gestational hypertension (table). Newborns born to mothers with preeclampsia had significantly prolonged QRS duration compared to neonates born after pregnancies without HDP (adjusted mean difference of 0.6 ms, 95% CI [0.04 – 1.16], p=0.04). The maximum amplitude of the R-wave in the V1-recording was significantly lower in newborns born to mothers with preeclampsia by 5% (linear scale: 0.95, 95% CI [0.9 – 0.996], p=0.03). These associations persisted after adjustment for additional covariates and restrictions on the study population. Gestational hypertension was not associated with significant differences in any of the investigated ECG parameters. Conclusion The cardiac conduction was affected in children born to mothers with preeclampsia compared with newborns born after pregnancies without HDP, including prolonged QRS duration and lower amplitude of the R-wave in V1 in the ECG. These findings could be an indicator of thickening of the left ventricular myocardium in newborns of mothers with preeclampsia. The potential clinical implications of these changes – short or long-term – are unknown and require further investigation.Table