Effect of pregnancy on ventricular and aortic dimensions in repaired tetralogy of Fallot

Background: To assess whether the cardiovascular adaptation to pregnancy in women with repaired tetralogy of Fallot (TOF) adversely affects haemodynamic stability; in particular with respect to right ventricular (RV) dilatation, pulmonary regurgitation or aortic root dilatation. Methods and Results: Retrospective cohort study of women with repaired TOF with paired Cardiovascular Magnetic Resonance (CMR) scans before and after their first pregnancy (baseline RV end systolic volume index 49mL/m2 and RV end diastolic volume index 118mL/m2) matched with a comparison group of nulliparous women with TOF. Cases were matched for age at baseline CMR scan, time between follow up of CMR scans, QRS duration, RV ejection fraction and indexed RV end systolic and diastolic volume at baseline. The 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 LV EDV and LV SV, consistent with a sustained small increase in LV SV due to pregnancy (53ml/m2 to 55ml/m2). Conclusion: 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 pre pregnancy counselling is tailored to their individual clinical status