Impact of frequent premature ventricular contractions on pregnancy outcomes.

OBJECTIVES: To determine cardiac and fetal/neonatal event rates among pregnant women with premature ventricular contractions (PVCs) and compare with control groups.

METHODS: Prospective case-control cohort study: 53 consecutive pregnancies in 49 women referred to the St. Paul's Hospital between 2010 and 2016 with PVC burden >1% in women without underlying cardiac disease. Maternal cardiac and fetal/neonatal outcomes were compared with two pregnant control groups: (1) supraventricular tachycardia (SVT) group of 53 women referred for a history of SVT/SVT in the current pregnancy and (2) low-risk group of 53 women with no cardiac disease.

RESULTS: The maximal PVC burden was 9.2% (range 1.1%-58.7%). Six of 53 (11%) pregnancies were complicated by a maternal cardiac event: heart failure n=1 and sustained ventricular tachycardia requiring therapy n=5 as compared with no cardiac events in both control groups. All women with an adverse event had a PVC burden >5%. Seven (13%) pregnancies were complicated by an adverse fetal and/or neonatal event and this was similar to the normal control group (5 (9%), P=0.45) and significantly less than the SVT group (16 (30%), P=0.03). The adverse fetal event was driven by small for gestational age neonates and preterm delivery.

CONCLUSIONS: In our cohort of pregnant women with a structurally normal heart and 'high' PVC burden, we found an adverse maternal event rate of 11%, and all events were successfully managed with medical therapy. The rate of adverse fetal events in the PVC group was similar to the normal control group.