Effect of Pregnancy on Ventricular and Aortic Dimensions in Repaired Tetralogy of Fallot

Background The aim was to assess whether cardiovascular adaptation to pregnancy in women with repaired tetralogy of Fallot ( TOF ) adversely affects hemodynamic stability, in particular with respect to right ventricular ( RV ) dilatation, pulmonary regurgitation, or aortic root dilatation. Methods and Results This was a retrospective cohort study of women with repaired TOF with paired cardiovascular magnetic resonance scans before and after their first pregnancy (baseline RV end systolic volume index 49 mL/m 2 and RV end diastolic volume index 118 mL/m 2 ) matched with a comparison group of nulliparous women with TOF . Cases were matched for age at baseline cardiovascular magnetic resonance scan, time between follow‐up of cardiovascular magnetic resonance scans, QRS duration, RV ejection fraction, and indexed RV end systolic and diastolic volume at baseline. Effect of pregnancy and time on parameters was assessed using mixed‐effects modelling. Nineteen women with repaired TOF who had completed their first pregnancy were identified and matched with 38 nulliparous women. We observed no deleterious effects of pregnancy on RV volumes, aortic dimensions, or exercise data. There was an effect of pregnancy observed in both left ventricular end diastolic volume and left ventricular stroke volume, consistent with a sustained small increase in left ventricular stroke volume attributed to pregnancy (53–55 mL/m 2 ). Conclusions Women with repaired TOF and with mild‐to‐moderate RV dilatation considering pregnancy can be reassured that pregnancy is unlikely to cause deterioration in their cardiovascular status. We recommend that women are routinely assessed and followed up before and after pregnancy and that prepregnancy counseling is tailored to their individual clinical status.