Poster Presentation Australasian Diabetes in Pregnancy Society Annual Scientific Meeting 2019

An insulin infusion designed for pregnancy provides comparable glycaemic control following betamethasone in women with gestational and pre-existing diabetes, although hypoglycaemia is more common in pre-existing diabetes  (#69)

Christopher W Rowe 1 2 , Matt Delbridge 3 , Karina Brown 3 , Brendan Watkins 3 , Jordan Addley 2 , Katie Wynne 1 2
  1. Department of Endocrinology and Diabetes, John Hunter Hospital, Newcastle, NSW, Australia
  2. School of Medicine and Public Health, University of Newcastle, Newcastle, NSW, Australia
  3. School of Rural Medicine, University of New England, Armidale, NSW, Australia

Background: Betamethasone-induced hyperglycaemia is common in women with diabetes in pregnancy and is associated with neonatal hypoglycaemia.  We have recently validated a pregnancy-specific intravenous insulin infusion protocol (P-IVI), demonstrating safe improvements in maternal glycaemic control in women with gestational diabetes and reduced incidence of neonatal hypoglycaemia [1].  However, the performance of the P-IVI in women with pre-existing diabetes is not known. 

Methods: Pilot data are presented of a prospective study of 17 pregnant women with pre-existing diabetes treated with P-IVI following betamethasone administration, compared to 65 similarly treated women with gestational diabetes at a tertiary hospital in Australia.  Glycaemic control and neonatal outcomes were compared. 

Results: Both groups of women were similar in terms of age, parity and gestational age at time of betamethasone administration.  There was no difference in the duration of on-infusion time with BGL at target (3.8–7mmol/L) between women with pre-existing diabetes (67 ± 17%) and gestational diabetes (68 ± 12%, p=0.87).  Mean on-infusion glucose was also similar (6.7±0.5 vs 6.6±0.4mmol/L, p=0.71).   However, 7/17 women with pre-existing diabetes had at least one episode of mild on-infusion hypoglycaemia (3-3.7mmol/L), compared to 1/65 women with gestational diabetes (p<0.0001).  Incidence of moderate on-infusion hypoglycaemia (<3mmol/L) was also higher in women with pre-existing diabetes compared to gestational diabetes (2/17 vs 0/65 p=0.005).   38/82 women gave birth to 40 offspring within 48 hours of betamethasone administration; the incidence of neonatal hypoglycaemia (neonatal BGL ≤2.5mmol/L within 48 hours of birth) was 9/31 for offspring of women with gestational diabetes, and 4/9 for women with pre-existing diabetes (p=0.40).    

Conclusions The P-IVI has similar glycaemic efficacy in women with pre-existing and gestational diabetes, although on-infusion hypoglycaemia was more common in women with pre-existing diabetes.  Comparable rates of neonatal hypoglycaemia were observed. The P-IVI is superior to our previous standard of care for women with gestational diabetes.  This preliminary data also supports the safety and efficacy of P-IVI in women with pre-existing diabetes, however individualized management may minimize maternal glucose variability in this higher-risk group.

  1. [1]. Rowe CW, Putt E, Brentnall O, Gebuehr A, Allabyrne J, Woods A, et al. An intravenous insulin protocol designed for pregnancy reduces neonatal hypoglycaemia following betamethasone administration in women with gestational diabetes. Diabet Med. 2018. Epub 2018/11/18. doi: 10.1111/dme.13864. PubMed PMID: 30443983.