CHD subtypes linked to increased risk of low Apgar scores in newborns

According to a study, several congenital heart defect (CHD) subtypes are associated with an elevated risk of low Apgar scores at 5 mins after birth in newborns.

CHDs remain the largest group of major congenital anomalies, with a prevalence of approximately 6 cases per 1,000 live births. [J Am Coll Cardiol 2002;39:1890–1900] “However, the relation between CHD subtypes and low Apgar scores remains unknown,” noted the researchers.

In this study, the researchers found that among CHD subtypes, anomalous pulmonary venous return was associated with the highest risk of low Apgar scores (adjusted odds ratio [aOR], 5.7), followed by hypoplastic left heart syndrome (aOR, 5.1) and transposition of the great arteries (aOR, 3.5).

“The identification of CHD subtypes at risk of complicated foetal-to-neonatal transitions holds the potential to improve both perinatal and neonatal care as well as long-term neurodevelopment in this patient group,” said the researchers.

Using data from the Danish Medical Birth Registry, the researchers conducted a population-based study involving 1,040,474 singleton infants (gestational age 22─45 weeks) born between 1997 and 2013. A total of 5,098 newborns were diagnosed with CHD, while the remaining newborns did not have the condition. [J Am Heart Assoc 2025;doi:10.1161/JAHA.124.038798]

Low Apgar scores (<7) occurred in 3 percent of newborns with CHD and 0.7 percent of those without CHD.

Compared with newborns without CHD, those with CHD had a 2.5-fold higher risk of low Apgar scores measured at 5 min after birth (aOR, 2.5).

The researchers also noted that the risk of low Apgar scores increased with the severity of CHD. Newborns with severe CHD had the highest prevalence of low Apgar scores (3.7 percent; aOR, 3.8), followed by those with moderate (3.3 percent; aOR, 2.6) and low (2.7 percent; aOR, 2.3) severity.

“Overall, the present study indicated that nearly all CHD subtypes were associated with an increased risk of a low Apgar score at 5 mins after birth. The association was most pronounced in severe and potentially cyanotic types of CHD,” said the researchers.