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.