The importance of small for gestational age in the risk assessment of infants with critical congenital heart disease

Background: Infants with critical congenital heart disease who require cardiothoracic surgical intervention may have significant post-operative mortality and morbidity. Infants who are small for gestational age <10th percentile with foetal growth restriction may have end-organ dysfunction that may predispose them to increased morbidity or mortality. Methods: A single-institution retrospective review was performed in 230 infants with congenital heart disease who had cardiothoracic surgical intervention <60 days of age. Pre-, peri-, and post-operative morbidity and mortality markers were collected along with demographics and anthropometric measurements. Results: There were 230 infants, 57 (23.3%) small for gestational age and 173 (70.6%) appropriate for gestational age. No significant difference was noted in pre-operative markers - gestational age, age at surgery, corrected gestational age, Society for Thoracic Surgeons and European Association for Cardiothoracic Surgery mortality score; or post-operative factors - length of stay, ventilation days, arrhythmias, need for extracorporeal membrane oxygenation, vocal cord dysfunction, hearing loss; or end-organ dysfunction - gastro-intestinal, renal, central nervous system, or genetic. Small for gestational age infants were more likely to have failed vision tests (p = 0.006). Small for gestational age infants were more likely to have increased 30-day (p = 0.005) and discharge mortality (p = 0.035). Small for gestational age infants with normal birth weight (>2500 g) were also at increased risk of 30-day mortality compared with appropriate for gestational age infants (p = 0.045). Conclusions: Small for gestational age infants with congenital heart disease who undergo cardiothoracic surgery <60 days of age have increased risk of mortality and failed vision screening. Assessment of foetal growth restriction as part of routine pre-operative screening may be beneficial.