Risk factors and outcomes for neonatal hypoglycaemia and neonatal hyperbilirubinaemia in pregnancies complicated by gestational diabetes mellitus: a single centre retrospective 3-year review.

AIM

To determine risk factors associated with neonatal hypoglycaemia and hyperbilirubinaemia, and assess their impact on neonatal outcomes in pregnancies complicated by gestational diabetes mellitus (GDM).

METHODS

Retrospective review investigating all pregnancies complicated by GDM at Campbelltown Hospital (Sydney, Australia) between 1 January 2013 and 31 December 2015. Main outcomes measured were neonatal hypoglycaemia (capillary glucose levels < 1.8 mmol/l) and hyperbilirubinaemia (total serum bilirubin levels greater than age-appropriate thresholds for phototherapy). Adjusted odds ratios [95% confidence interval (CI)] are shown, calculated by multivariable logistic regression.

RESULTS

Some 60 (7.8%) infants developed hypoglycaemia, 58 (7.5%) developed hyperbilirubinaemia and 13 (1.7%) developed both. Risk of developing hypoglycaemia increased 1.8-fold (95% CI 1.3-2.6, P < 0.001) per gestational week at GDM diagnosis, 1.1-fold (95% CI 1.0-1.3, P = 0.04) per mmol/l maternal fasting glucose, 6.2-fold (95% CI 2.6-16.2, P < 0.001) with maternal history of macrosomia, 10.8-fold (95% CI 4.1-27.6, P < 0.001) with multiple pregnancy and 1.1-fold (95% CI 1.0-1.3, P = 0.04) per gestational week at birth. Risk of hyperbilirubinaemia increased with multiple pregnancy (26.4; 95% CI 11.7-59.7, P < 0.001), and 1.5-fold (95% CI 1.1-2.1, P = 0.01) per gestational week at GDM diagnosis. Hypoglycaemia was associated with a 2.8-fold (95% CI 1.1-7.1, P = 0.03) increased risk of macrosomia, a 5.4-fold (95% CI 1.1-27.3, P = 0.04) excess risk of shoulder dystocia and a 6.4-fold increased risk of 5-min APGAR ≤ 7 (95% CI 1.2-1.7, P < 0.001). Hyperbilirubinaemia was associated with an excess risk of polycythaemia (packed cell volume > 0.6; 97.1, 95% CI 38.9-241.5, P < 0.001).

CONCLUSIONS

Neonatal hypoglycaemia and hyperbilirubinaemia largely occur in different pregnancies. Both are associated with earlier GDM diagnosis; however, hypoglycaemia is more associated with maternal glycaemia and its sequelae, and hyperbilirubinaemia is associated with polycythaemia.