EP08.40: Determining the hospital costs of macrosomia after diabetes in pregnancy

To determine the influence of macrosomia on neonatal and maternal hospital resource utilisation following diabetes in pregnancy. This was a retrospective cohort of singleton pregnancies complicated by pre-existing diabetes at a regional maternity hospital (2011 to 2020). Primary exposure was macrosomia (birthweight above the 90th percentile for gestational age). A validated electronic hospital database was used to collate patient demographics, pregnancy complications, birth events, and neonatal outcomes. The main outcome was peripartum hospital resource utilisation for neonates and mothers as measured by length of hospital stay, intensive care unit admission, and resource intensity weight (RIWTM) - a proxy of healthcare costs. Descriptive and inferential statistics were used to evaluate the relationship between macrosomia and hospital resource utilisation. 1241 pregnancies were included (87.5% with type 2 diabetes). Incidence of macrosomia was 48.5%, including one-third with birthweights above the 97th percentile. Younger maternal age, multiparity, and cigarette smoking were more common in the macrosomia group. Significantly more newborns with macrosomia required NICU admission than compared to appropriately grown controls (42% vs 29%, p < 0.0001), despite no difference in gestational age at birth, Caesarean section, or other neonatal complications. Hospital stays were longer for neonates with macrosomia (10.7 days (SD 20.7) vs 8.4 days (SD 16.8), p = 0.036) and their mothers (4.4 days (SD 3.6) vs 3.8 days (SD 3.0), p = 0.0003), but there was no difference in resource intensity weights for those with macrosomia compared to diabetes alone (p = 0.726). Macrosomia confers an additional burden on hospital resources beyond diabetes in pregnancy alone. Better understanding of the hospital care required after macrosomia will improve allocation of limited healthcare resources and counselling of families experiencing this common pregnancy complication.