Introduction: Neonatal hypoglycaemia (NH) is common in infants born soon after betamethasone administration, and may be reduced by at-target peri-partum glycaemic control. A Pregnancy-specific Intravenous Insulin-Glucose Infusion (PIIGI) protocol was introduced at a tertiary hospital in June 2017, replacing a generic Adult IntraVenous Insulin protocol (AIVI) not designed for pregnancy, without change in indication for IV insulin (initiated with any BGL>6.7 mmol/L following betamethasone, and continued for 24 hours after the final dose of betamethasone). Capillary glucose levels are measured every 3060 minutes whilst on infusion.
Patients and methods: A prospective audit June 2017-May 2018 captured all uses of PIIGI following betamethasone in women with gestational diabetes (n=65), and compared to a similar retrospective cohort treated with AIVI (n=86). Primary outcome was percentage of on-infusion time at target (BGL 3.87 mmol/L). Secondary outcomes were percentage time with critical hyperglycaemia (BGL>10 mmol/L) or hypoglycaemia (BGL<3.8 mmol/L), and incidence of NH (BGL<2.7 mmol/L in first 48 hours if betamethasone given within 2 days of birth). As this was a real-world analysis of practice, a waiver of consent was granted by the Human Research Ethics Committee.
Results: On-infusion time at target was 68% (95%CI 6471%) for PIIGI compared to 55% (95%CI 5060%) for AIVI (P=0.0002). Critical hyperglycaemia was lower with PIIGI compared to AIVI (2% vs 5%, P=0.006), with no change in rate of hypoglycaemia (0.1% vs 0.5%, P=0.09). NH occurred with 11/31 (35%) of births following PIIGI, compared to 29/48 (60%) births following AIVI (P=0.03). A multiple logistic regression model adjusting for potential confounders gave an odds ratio for NH with PIIGI of 0.30 (95%CI 0.110.82, P=0.02).
Conclusions: An infusion protocol designed for pregnancy effectively controlled maternal hyperglycaemia following betamethasone. This is the first protocol to show reduction in betamethasone-associated NH associated with optimum maternal glycaemic control.