PH Screening Can Be Given Only to Premature Babies with Risk Factors, Study Suggests

Researchers suggest that routine echocardiographic (ECG) screening for pulmonary hypertension (PH) in premature infants might only be needed if certain risk factors are evident. While the proposed approach would identify most children affected and be of help to hospitals, researchers acknowledge that lung hypertension might go undetected in some babies.

The change is estimated to ease a hospital’s load of required heart exams by more than 40 percent.

These findings, presented in the report, “Pulmonary hypertension in preterm infants: results of a prospective screening program,” illustrate the difficulties of allocating economic and human resources in a healthcare setting. The work was published in the Journal of Perinatology.

To study risk factors for PH among premature infants, researchers at Yale University School of Medicine examined data on 204 infants born before gestational week 32. All were still in a neonatal intensive care unit at 36 weeks corrected gestational age. Corrected gestational age is a term used for preterm infants, which represents their age, calculated from the actual birth date, minus the number of weeks a baby was premature.

Since bronchopulmonary dysplasia (BPD) — a lung condition affecting a large proportion of premature babies — is known to be linked to PH, researchers performed separate analyses on children with and without the condition.

Among the infants without BPD, 45 had a low birthweight, and 15 had symptoms that made physicians suspect PH.

In the group with BPD, 27.7 percent had evidence of increased lung blood pressure at the initial ECG screening. When researchers adjusted analyses for birthweight and gestational age, they noted that severe bleeding inside the heart, an atrial septal defect, and necrotizing enterocolitis (a severe gut condition) predicted the presence of PH in these children.

In babies with BPD but without necrotizing colitis, only a low birthweight was linked to lung hypertension.

Among those without BPD, necrotizing enterocolitis was the only factor that was linked to PH, which was suspected in only 11 percent of the infants during the initial screening.

Looking at all the children, it was apparent that necrotizing colitis was the main risk factor for PH — 57 percent of infants with the gut condition had lung hypertension. Among those with neither intestinal injury nor BPD, only 5 percent had lung hypertension.

Further analyses suggested that if physicians screened only infants with necrotizing colitis, as well as those with BPD with a birthweight of less than 840 grams (less than 2 pounds), they would detect 84 percent of the infants affected by lung hypertension. Such an approach would reduce the number of ECG tests by 43 percent — at a cost of missing to detect lung hypertension in eight of the infants in the study.