Foetal congenital heart defects can triple risk of preeclampsia, preterm birth: Study

New Delhi: Foetus suffering from major congenital heart defects (MCHDs) may triple the risk of adverse pregnancy outcomes such as preeclampsia and preterm birth, finds a study.

MCHDs occur in approximately 1 in 100 live births and can negatively impact both the health of the mother and the long-term outcomes for the child.

Researchers from the Statens Serum Institut in Copenhagen showed that about 23 per cent of pregnancies affected by foetal MCHD also result in adverse obstetric outcomes including preeclampsia, preterm birth, fetal growth restriction, and placental abruption.

The findings were based on data from 534,170 pregnancies, including 745 cases complicated by foetal MCHDs in Denmark. Pregnancies resulting in live births after 24 gestational weeks and without chromosomal aberrations were included in the study.

The study, published in JAMA Pediatrics, also assessed 11 MCHD subtypes, including univentricular heart, transposition of the great arteries (TGA), and atrioventricular septal defect.

Data on the obstetric risk profile for specific MCHD subtypes are limited and thus slow down the development of preventive interventions.

Pregnancies complicated by MCHDs suffered an adverse obstetric outcome rate of 22.8 per cent.

While foetal growth restriction occurred in 6.7 per cent of MCHD pregnancies, a higher prevalence of preeclampsia was found in 6.2 per cent of MCHD pregnancies.

They also found a 15.7 per cent increased risk of preterm births in MCHD pregnancies. While Placental abruption was rare it showed a significant trend toward higher incidence 0.9 per cent.

All MCHD subtypes, except TGA, were associated with significantly higher odds of the composite adverse outcome. The highest risk was observed in pregnancies with truncus arteriosus, pulmonary atresia with intact ventricular septum, and Ebstein anomaly.

The team also confirmed the findings with a meta-analysis of 5,993 cases of MCHDs. Notably, pregnancies with fetal TGA did not exhibit elevated risks of preeclampsia, preterm birth, or fetal growth restriction, the findings showed.