Efficacy and safety of the pregnancy-IVI, an intravenous insulin protocol for pregnancy, following antenatal betamethasone in type 1 and type 2 diabetes

AIMS Hyperglycaemia following antenatal corticosteroids is common in women with diabetes in pregnancy, and validated algorithms to maintain pregnancy-specific glucose targets are lacking. The Pregnancy-IVI, an intravenous-insulin (IVI) algorithm, has been validated in gestational diabetes; however, its performance in pre-existing diabetes (Type 1 and Type 2 diabetes) is not known. We hypothesised that Pregnancy-IVI would be superior to a generic Adult-IVI protocol (prior standard of care) following betamethasone in women with pre-existing diabetes. METHODS A retrospective cohort study enrolled all women with pre-existing diabetes at a tertiary centre receiving betamethasone and treated with IVI according to one of two protocols: Adult-IVI (n = 73, 2014-2017) or Pregnancy-IVI (n = 62, 2017-2020). The primary outcome was on-IVI glycaemic time-in-range (capillary blood glucose (BGL) 3.8-7.0 mmol/L). Secondary outcomes included time with critical hyperglycaemia (BGL > 10 mmol/L); occurrence of maternal hypoglycaemia (BGL