Previous studies have shown that preterm birth, low birth weight, and maternal gestational weight gain influence surgical outcomes in infants with congenital heart disease (CHD). Rodent models of maternal diabetes (DM) and fetal hypoxia suggest these prenatal exposures are associated with increased risk of myocardial ischemic reperfusion injury (IRI). Whether maternal DM impacts surgical outcomes of infants with CHD, particularly those requiring cardiopulmonary bypass (CPB), and whether this relates to greater IRI, has not been explored.
Methods and Results
Infants of mothers with DM (IDMs) undergoing CPB at < 1 year were identified and matched with infants whose mothers did not have DM, for surgical intervention, age at surgery, sex, gestational age at birth, being small for gestational age (SGA), and having genetic syndromes (trisomy 21 and 22q11.2 deletion syndrome). Outcomes included postoperative intensive care unit (ICU) and hospital lengths of stay (LOS) and measures indicative of greater IRI (Table). DM subtypes were combined for the main analyses and then separated into gestational (GDM) and pregestational DM. Surgeries were coded using the Risk Adjustment for Congenital Heart Surgery (RACHS) scale and pooled into Groups 1-3 (A) and 4-6 (B). Eighty IDMs and 149 controls were included, 188 in RACHS A and 41 in RACHS B subgroups. IDM and control groups were statistically indistinguishable in most baseline characteristics except: DM mothers were older (33±6 vs 30±6 years, P< 0.001) and more likely to deliver via Caesarean section (49% vs 34%, P=0.03), and IDMs were born earlier (37±2 vs 38±2 weeks, P< 0.001). Within each RACHS group, there were no significant differences in outcomes between IDMs and controls (Table). IDMs exposed to GDM exhibited trends towards similar or even better outcomes after surgery (IDMs vs controls; Group A ICU LOS: 3±3 vs 4±3 days, P=0.02; Group B highest glucose: 13.4±2.0 vs 16.7±3.0 mmol/L, P=0.01), while IDMs of pregestational DM mothers exhibited signs of worse outcomes in Group A (hospital LOS: 20±29 vs 10±7 days, P=0.046; highest urea: 11.0±4.4 vs 8.4±4.2 mmol/L, P=0.04) with trends towards worse outcomes in Group B (PRISM score: 16±9 vs 10±5, P=0.11; highest glucose: 16.7±1.3 vs 14.3±2.7 mmol/L, P=0.06).