by Justin Jackson , Medical Xpress

Credit: Puwadon Sang-ngern from Pexels

Research led by the Statens Serum Institut in Copenhagen has revealed that nearly 23% of pregnancies affected by fetal major congenital heart defects also result in adverse obstetric outcomes.

Major congenital heart defects (MCHDs) occur in approximately 1 in 100 live births. Prior research has indicated that impaired placental development may contribute to obstetric complications in pregnancies with MCHDs.

Conditions such as preeclampsia, preterm birth, and fetal growth restriction are of particular concern because they negatively affect both maternal health and long-term outcomes for children born with these defects.

Limited data exist on the obstetric risk profile for specific MCHD subtypes, slowing the development of preventive interventions and individualized care strategies for affected pregnancies.

In the study "Adverse Obstetric Outcomes in Pregnancies With Major Fetal Congenital Heart Defects," published in JAMA Pediatrics, researchers analyzed data from the Danish Fetal Medicine Database, which covers about 95% of single baby pregnancies in Denmark from June 1, 2008, to June 1, 2018, alongside results from a meta-analysis of international studies.

Pregnancies resulting in live births after 24 gestational weeks and without chromosomal aberrations were included. In all, 534,170 pregnancies, including 745 cases complicated by fetal MCHDs were examined.

The primary outcome was a composite measure of placenta-related adverse obstetric outcomes, including preeclampsia, preterm birth, fetal growth restriction, and placental abruption. Secondary outcomes were analyzed individually. Eleven MCHD subtypes were assessed, including univentricular heart, transposition of the great arteries (TGA), and atrioventricular septal defect.

Statistical analyses used generalized estimating equations to calculate adjusted odds ratios (AORs), controlling for maternal factors such as age, body mass index, smoking status, and year of delivery. A meta-analysis used random-effects models to pool effect sizes from 10 international studies.

Pregnancies complicated by MCHDs exhibited a composite adverse obstetric outcome rate of 22.8% compared with 9.0% in pregnancies without MCHDs (AOR, 2.96).

Fetal growth restriction occurred in 6.7% of MCHD pregnancies compared to 2.3% in non-MCHD pregnancies. A higher prevalence of preeclampsia was found in MCHD pregnancies (6.2% vs. 3.1%) and an increased risk of preterm births in MCHD pregnancies (15.7% vs. 4.6%). Placental abruption was rare but showed a significant trend toward higher incidence (0.9% vs. 0.4%).

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 (AOR, 6.35), pulmonary atresia with intact ventricular septum (AOR, 5.51), and Ebstein anomaly (AOR, 5.09).

The meta-analysis, which included data from 5,993 cases of MCHDs, confirmed these findings. Notably, pregnancies with fetal TGA did not exhibit elevated risks of preeclampsia, preterm birth, or fetal growth restriction.

With a nearly threefold increased risk of adverse obstetric outcomes in pregnancies affected by MCHDs, the research identifies the need for targeted interventions. Future research is recommended to evaluate preventive measures and to explore mechanisms linking placental dysfunction to specific MCHDs.

More information: Gitte Hedermann et al, Adverse Obstetric Outcomes in Pregnancies With Major Fetal Congenital Heart Defects, JAMA Pediatrics (2024). DOI: 10.1001/jamapediatrics.2024.5073

Journal information: JAMA Pediatrics 

© 2024 Science X Network