Impact of Paroxysmal Supraventricular Tachycardia on Pregnancy Outcomes.

Background: Paroxysmal supraventricular tachycardia (PSVT) is one of the most common arrhythmias in pregnant women. However, studies investigating the risk of PSVT in pregnancy are lacking. In pregnancy, we aimed to determine the (1) proportion of women presenting with new-onset PSVT, (2) impact of prior PSVT history on episode severity and management, and (3) rate of adverse maternal and fetal or neonatal outcomes associated with PSVT. Methods: Retrospective case-control study: 77 consecutive pregnancies in 75 women referred to the St Paul's Hospital Cardiac Obstetrics Clinic (2010-2022) with a history or new presentation of PSVT. Maternal obstetric and fetal or neonatal adverse outcomes were compared to a healthy control group. Results: Sixty-three pregnancies (82%) had a history of PSVT and 14 (18%) were new-onset in pregnancy. Sixty-eight percent of those with PSVT history had recurrence in pregnancy. Women with a recent history of PSVT within 5 years of pregnancy were more likely to experience recurrence than women with a remote history (81% vs 31%, Conclusions: PSVT events were safely managed in pregnancy with similar obstetric and fetal or neonatal outcomes as controls. However, recurrence of PSVT during pregnancy is frequent and leads to management complexities among those with a history, reinforcing the need for pre-pregnancy counselling and catheter ablation for definitive management.