Prenatal Screening Sets Up Younger Babies for Heart Defect Surgery

Even with the arrival of mandatory newborn screening for congenital heart defects (CHDs), prenatal diagnosis was tied to younger age at corrective surgery, a retrospective found.

From 2015 to 2021, the first heart surgery at a high-volume congenital heart center occurred 7.1 days sooner in newborns with critical CHDs diagnosed prenatally versus postnatally (P<0.001), reported researchers led by Joyce Woo, MD, MS, of Lurie Children's Hospital of Chicago and Northwestern University Feinberg School of Medicine, in Circulation: Cardiovascular Quality and Outcomes.

"Our study quantifies the tremendous importance of prenatal diagnosis for infants with congenital heart disease," said Woo in a press release. "For infants with critical disease especially, getting surgery a week earlier can make a big difference in the development of the brain and other organs."

The investigators reported that the relationship between age at surgery and prenatal diagnosis varied for noncritical cardiac defects: surgery in prenatally diagnosed babies occurred from 1.8 months sooner (noncritical coarctation of the aorta) to 12.4 months sooner (atrial septal defects), whereas babies with tetralogy of Fallot, vascular ring, and atrioventricular septal defects did not differ in age of surgery between the prenatally versus postnatally diagnosed.

"Notably, the variables available in the dataset limited our ability to control for other anatomic and physiological factors that contribute toward disease severity, such as the size of a septal defect, depressed ventricular function, or aortic isthmus size. Therefore, it was more difficult to elucidate an association across the noncritical CHD diagnoses compared with the critical CHD cohort," the authors explained.

They acknowledged that there is a lack of consistent links between prenatal diagnosis and surgical mortality or postoperative length of stay in the literature. However, early age at CHD surgery has an established association with better long-term outcomes in any case, the team noted.

Standard prenatal screening for CHD relies on obstetric sonograms followed by fetal echocardiography, which flags more than 80% of significant CHDs, according to the CDC. A recent study found that in Massachusetts, prenatal diagnosis of critical CHDs increased from 46% to 76% of cases from 2004 to 2018.

Advances in prenatal screening occurred in tandem with a national transition to mandatory newborn pulse oximetry-based screening that started in 2011, when the U.S. Department of Health and Human Services endorsed critical CHD for universal newborn screening.

Woo and colleagues suggested that Illinois' mandate for neonatal screening, which took effect in August 2013, was still less helpful than prenatal diagnosis.

"In our analysis, birth at a level III neonatal intensive care unit -- where echocardiography must be available -- was still associated with older average age at surgery than those born at a CHD surgical center," the researchers wrote. "This implies that even the technical ability to rapidly diagnose critical CHDs postnatally is not sufficient to overcome the benefits of prenatal diagnosis in our cohort."

The investigators noted that the single-center report may have limited generalizability, however, as Lurie Children's serves a Midwest population mainly covering Illinois, northwest Indiana, and southern Wisconsin. In addition, unmeasured confounders such as lesion severity or distance from Lurie Children's may account for some of the relationship between prenatal diagnosis and younger age at surgery.

"Prospective, region-specific analyses with even more detailed outcomes, as well as granular and high-quality parent- and patient-level data, will be essential to future studies that investigate causality," Woo's group urged.

The retrospective cohort study included 1,131 children up to age 9 (47% of whom were girls) who had their initial cardiac surgery at Woo's institution from 2015 through 2021. Data were pulled from institutional contributions to the Society of Thoracic Surgeons Congenital Heart Surgery Database.

A prenatal CHD diagnosis had been available for 47% of the cohort, of which 38% had a critical CHD requiring very early heart surgery.

Median age at first surgery was 7 days for the critical CHD group and 7 months for babies with a noncritical CHD.

Of note, among babies with critical CHDs, Asian patients on average received surgery 6 days later than Hispanic patients (P=0.04).

"More investigation into potential reasons for this consistent finding -- which may be due to worse access to diagnosis, more severe disease/clinical presentation, slower preoperative weight gain, cultural factors impacting parent decision-making, or provider bias in decision-making -- is necessary as part of efforts to achieve healthcare equity," Woo and colleagues wrote.

Comment