145 Preterm infants with minor congenital anomalies: additional risk for neonatal complications

Abstract

Previous studies have shown that infants with major congenital anomalies were at higher risk of being born preterm. This relationship has not yet been fully investigated in infants with minor congenital anomalies. Furthermore, it is not known if presence of mCA is associated with higher risk of neonatal complications. To examine the relationship between minor congenital anomalies and gestational age (GA) at birth and to determine whether the presence of minor congenital anomalies is associated with higher rates of neonatal complications in preterm infants. Data from infants born at 29–36 weeks GA and admitted to NICUs in the Canadian Neonatal Network during 2010–16 were reviewed. Infants with major congenital anomalies or moribund on admission were excluded. Minor congenital anomalies were defined as birth defects not requiring specific medical management in the immediate post-natal period. Neonatal complications were compared between infants with versus without minor congenital anomalies adjusting for GA, small for GA, sex, smoking, drug use, gestational diabetes and hypertension using multivariable linear or logistic regression models with GEE approach. This protocol was approved by our institution’s research ethics board. In total, 5294 infants (11%) were born with ≥1 mCA. Figure 1 shows the U-shape relationship between minor congenital anomalies and GA with higher rates observed among those born at 29–31 weeks’ GA. Preterm infants with vs. without minor congenital anomalies were more likely to be boys (61% vs. 55%), of lower birth weight (2005 vs. 2064g), born by C-section (60% vs. 54%), have SNAPII score >20 (8% vs. 4%) and require intensive resuscitation at birth (15% vs. 8%). Duration of neonatal hospitalization was longer for infants with minor congenital anomalies with median of 18 (9–38) vs. 11 (6–22) days. After adjusting for confounders, mortality rate was higher among infants with mCA (3.6% vs 0.7%; OR 4.9, 95% CI 3.4–7.0). Moreover, infants with mCA were at higher risk of respiratory distress syndrome (OR 1.3, 95% ci 1.2–1.4), air leak (OR 1.7, 95% CI 1.4–2.1), late onset sepsis (OR 2.1, 95% CI 1.7–2.4), and NEC stage ≥2 (OR 2.0, 95% CI 1.6–2.5). Minor CA is associated with lower GA. Preterm infants with minor congenital anomalies are at higher risk of significant neonatal complications. These infants may warrant more careful monitoring during the postnatal period.