Congenital Heart Defects and Apgar Score at Birth, a Nationwide Study

Area of Science:

• Neonatal Research
• Pediatric Cardiology
• Public Health

Background:

• Low Apgar scores are linked to adverse outcomes in newborns with congenital heart defects (CHDs).
• The specific associations between different CHD subtypes and low Apgar scores were previously unclear.
• This study investigated the relationship between major CHD subtypes and low Apgar scores at 5 minutes.

Purpose of the Study:

• To determine the association between major congenital heart defect subtypes and low Apgar scores at 5 minutes.
• To identify specific CHD subtypes with the highest risk of low Apgar scores.
• To explore potential mediating factors, such as preterm birth, in the CHD-low Apgar score relationship.

Main Methods:

• A population-based study of 1,040,474 liveborn singletons in Denmark (1997-2013).
• Confounder-adjusted, multivariable logistic regression was used to estimate associations.
• Mediation analyses were conducted to examine underlying mechanisms.

Main Results:

• Newborns with CHDs had a higher prevalence of low Apgar scores (3.0%) compared to those without (0.7%).
• Overall, CHD was associated with an increased risk of low Apgar scores (aOR, 2.5).
• Anomalous pulmonary venous return (aOR, 5.7), hypoplastic left heart syndrome (aOR, 5.1), and transposition of the great arteries (aOR, 3.5) showed the highest risks. Preterm birth explained 25.2% of the association.

Conclusions:

• Nearly all CHD subtypes are linked to an increased risk of low Apgar scores.
• The association is strongest for severe and cyanotic CHD types.
• Findings suggest CHDs complicate the fetal-to-neonatal transition, highlighting areas for potential intervention.