Factors Associated with Predischarge Morbidity and Mortality in Small for Gestational Age Infants: A Single-Center Retrospective Cohort Study

Objective: To identify factors associated with predischarge morbidity and mortality among small for gestational age infants. Study Design: We conducted a retrospective single-center cohort study of small for gestational age infants admitted to a level IV neonatal intensive care unit. We determined the association of clinical characteristics, congenital anomalies, and genetic disorders with the primary outcome of predischarge morbidity or mortality and characterized morbidity and mortality across congenital anomaly subgroups. Results: Among 293 small for gestational age infants, 18 (6.1%) had a genetic disorder and 103 (35.2%) had a major congenital anomaly, with congenital heart disease (CHD) representing the largest subgroup. The primary outcome of morbidity or mortality occurred in 93 infants (31.7%); 74 infants (25.3%) experienced morbidity and 19 (6.5%) died. CHD (adjusted odds ratio [aOR]: 16.5, 95% CI 6.44-45.7) and multiple congenital anomalies (aOR: 17.8, 95% CI 4.64-71.1) were found to be strongly associated with morbidity or mortality, after accounting for sex, maternal race, and intubation > 7 days. Statistically significant associations were also found with the presence of musculoskeletal anomalies as well as genetic disorders in infants without congenital anomalies, though in limited sample sizes. CHD was the largest contributor to morbidity, whereas multiple congenital anomalies accounted for the greatest proportion of mortality. Infants with abdominal wall defects and central nervous system anomalies experienced no morbidity or mortality. Conclusion: Congenital heart disease and multiple congenital anomalies were strongly associated with morbidity and mortality among SGA infants, whereas the degree of SGA alone was not. These findings suggest that risk is not explained by the degree of SGA alone and may be more strongly associated with congenital disease and other underlying factors.