Uteroplacental Doppler flow and pregnancy outcome in women with tetralogy of Fallot

Objective Pregnancy in women with surgically corrected tetralogy of Fallot (ToF) is associated with cardiac, obstetric and neonatal complications. We compared uteroplacental Doppler flow (UDF) measurements and pregnancy outcome in women with ToF and in healthy women and aimed to assess whether a relationship exists between cardiac function and UDF in women with ToF.
Methods We evaluated prospectively pregnant women with ToF and healthy pregnant women from the ZAHARA studies. Clinical evaluation, standardized echocardiography and UDF measurements were performed at 20 and 32weeks’ gestation.
Results We included 62 women with ToF and 69 healthy controls. Cardiac complications, mostly arrhythmia, occurred in 8.1% of women with ToF. There was a higher incidence of small-for-gestational age (21.0% vs 4.4%, P=0.004) and low birth weight (16.1% vs 2.9%, P=0.009) in the group of women with ToF than in healthy controls. In women with ToF, early diastolic notching of uterine artery waveform at 20 and 32weeks occurred more frequently (9.8% vs 1.5%, P=0.034 and 7.0% vs 0%, P=0.025, respectively) and the umbilical artery pulsatility index at 32 weeks was higher (1.02±0.20 vs 0.94±0.17, P=0.015) than in healthy controls. Right ventricular function parameters prepregnancy and at 20weeks’ gestationwere significantly associated with abnormal UDF. UDF parameters were associated with adverse neonatal outcome.
Conclusion The majority of women with surgically corrected ToF tolerate pregnancy well. However, UDF indices are more frequently abnormal in these women, suggesting impaired placentation. The association of impaired right ventricular function parameters with abnormal UDF suggests that cardiac dysfunction contributes to defective placentation or placental perfusion mismatch and may explain the increased incidence of obstetric and neonatal complications.