Double Jeopardy: Prematurity and Congenital Heart Disease—What's Known and Why It's Important

Abstract

This article is based on a composite of talks presented during the Double Jeopardy: Prematurity and Congenital Heart Disease Plenary Session at NeoHeart 2020, a global virtual conference. Prematurity and low weight remain significant risk factors for mortality after neonatal cardiac surgery despite a steady increase in survival. Newer and lower weight thresholds for operability are constantly generated as surgeons gather proficiency, technical mastery, and experience in performing complex procedures on extremely small infants. The relationship between birth weight and survival after cardiac surgery is nonlinear with 2 kilograms (kg) being an inflection point below which marked decline in survival occurs. The prevalence of congenital heart disease (CHD) in premature infants is more than twice that in term born infants. Increased risk of preterm birth in infants with CHD is most commonly due to spontaneous preterm birth and remains poorly understood. Advances in Neonatal-Perinatal medicine have led to a marked improvement in survival of neonates born prematurely over the last several decades. However, the risk of severe morbidities including retinopathy of prematurity, intraventricular hemorrhage, bronchopulmonary dysplasia and necrotizing enterocolitis remains significant in extremely low birth weight infants. Premature infants with CHD are at a greater risk of prematurity related morbidities than premature infants without CHD. Interventions that have been successful in decreasing the risk of these morbidities are addressed.

Delivery room and early postnatal management of neonates with congenital heart disease

“…39 Therefore, in addition to prematurity, the underlying CHD also contributes to the morbidity and mortality of preterm infants. [40][41][42] Finally, the preterm delivery of certain CHD may limit options for immediate and future postnatal cardiac interventions, and decisions regarding resuscitation should take this into account.…”

“…Placental separation, surfactant deficiency, underdeveloped gas exchange units, and a noncompliant cardiovascular system are inadequate to maintain oxygenation and perfusion in preterm infants 39 . Therefore, in addition to prematurity, the underlying CHD also contributes to the morbidity and mortality of preterm infants 40–42 . Finally, the preterm delivery of certain CHD may limit options for immediate and future postnatal cardiac interventions, and decisions regarding resuscitation should take this into account.…”

Complex neonatal congenital heart surgery in Nevada

“…1 Surgical mortality may also be affected by low birth weight, syndromes, and associated noncardiac malformations. [2][3][4][5][6] This retrospective study investigated our center's experience with those undergoing STAT category 4 and 5 procedures and the possible influence on outcome by low birth weight and associated noncardiac malformations.…”

“…The Society of Thoracic Surgeons (STS)‐European Association for Cardio‐Thoracic Surgery (EACTS) The Society of Thoracic Surgeons‐European Association for Cardio‐Thoracic Surgery (STAT) 4 and 5 category procedures comprise about quarter of a congenital heart program's surgical cases; however, they account for most surgical mortalities 1 . Surgical mortality may also be affected by low birth weight, syndromes, and associated noncardiac malformations 2–6 …”

Invited Perspective: Air Pollution and Congenital Heart Defects (CHDs)—a Summary of Two Decades and Future Direction in Research

“…Infants with CHDs have a greater risk of being born preterm. 13 However, it is still unknown whether abnormal heart development causes preterm birth or if a common antecedent factor, such as air pollution exposure, causes CHDs as well as preterm birth. In future studies, conditioning on gestational age should be avoided or examined carefully by using directed acyclic graphs.…”