Objective: To investigate the cost effectiveness of continuous glucose monitoring (CGM) when compared to self-monitoring of blood glucose (SMBG) in preventing perinatal complications in women with type 1 diabetes during pregnancy.
Methods: This retrospective matched cohort study included women with type 1 diabetes referred to a state-wide tertiary obstetric centre before and after the introduction of government funded CGM in March 2019. Women using CGM were matched in a 1:1 ratio various patient characteristics with a cohort of women with type 1 diabetes who exclusively used SMBG and delivered prior to March 2019. Data regarding glycaemic control during pregnancy and pregnancy outcomes was collected by auditing medical records and standardised cost data was used to quantify cost effectiveness.
Results: A total of 98 women were included in the study, 49 who self-monitored blood glucose and 49 who used CGM throughout pregnancy. We observed a significant reduction in pre-term (RR 0.600; 95% CI 0.39 – 0.922; p=0.026) and very pre-term birth rates (RR –inverse 1.089; 95% CI 1.002-1.184; p=0.041) in the CGM group. There was a significant reduction in length of maternal antenatal inpatient hospital stay (p<0.01) and Adult Special Care Unit stay (p=0.013) and NICU admission (p=0.0262) in the continuous glucose monitoring group when compared to the self-monitoring group. Continuous glucose monitors represented a net cost saving to the health care sector of $12 063 per pregnancy where the device was used. When only accounting for the cost of devices, we calculated an incremental cost effectiveness ratio of $2185 per pre-term birth prevented.
Conclusions: Continuous glucose monitor use in pregnancy is a cost effective intervention for reducing the risk of pre-term birth in women with type 1 diabetes. As well as improving pregnancy outcomes, continuous glucose monitoring results in a net cost benefit to the health sector when compared to self-monitoring of blood glucose