William Sansum Diabetes Center's Dr. Kristin Castorino was the only United States investigator on the study.
Previous studies have suggested CGM can reduce HbA1c levels and exposure time to hypoglycaemia but there is little evidence to prove how beneficial it can be in expectant mothers.
The work was carried out because one in two newborns of women with type 1 diabetes can sometimes face complications as a result of being exposed to maternal high blood sugar levels. There has been limited progress with birth outcomes not improving much in the past three or four decades.
The authors of the international trial say that, as a result of these findings, this type of monitoring should now be offered to all pregnant women with type 1 diabetes to help improve outcomes for newborns.
The Continuous Glucose Monitoring in Women with Type 1 Diabetes in Pregnancy Trial (CONCEPTT) involved 214 pregnant women with type 1 diabetes aged between 18 and 40 who had been relying on either insulin pumps or multiple daily injections to control their condition. They were then were randomly allocated to use the CGM device, and half to use the traditional monitoring method.
The continuous glucose monitoring device helped reduce blood sugar levels by a small amount [0.2% (-0.34 to -0.03)]. Compared to traditional monitoring, women who used the device spent more time in the normal range for blood sugar levels (68% vs 61% – equivalent to 100 minutes more per day) and spent less time with high blood sugar levels (27% vs 32%– equivalent to 1 hour less per day).
The number of severe hypoglycaemia episodes and the time spent hypoglycemic was comparable in the two groups (18 vs 21 and 3% vs 4% respectively).
Study author Dr Denice Feig, from the University of Toronto and the Sinai Health System, said: “For a long time there has been limited progress in improving birth outcomes for women with type 1 diabetes, so we’re pleased that our study offers a new option to help pregnant women with diabetes and their children.
“Keeping blood sugar levels within the normal range during pregnancy for women with type 1 diabetes is crucial to reduce risks for the mother and child. However, with traditional monitoring, this can be difficult as sensitivity to insulin fluctuates throughout pregnancy, meaning that accurately adjusting insulin doses is complex. As a result of our findings, we believe that this type of monitoring should be offered to all pregnant women with type 1 diabetes.”
Professor Helen Murphy, co-principal investigator of CONCEPTT who is from the University of East Anglia, said: “Women using insulin pumps and insulin injections benefitted equally, meaning our results are applicable to all pregnant women with type 1 diabetes. Although continuous monitoring is more expensive than standard glucose testing, there is potential for substantial healthcare savings.
“An admission to the neonatal intensive care unit is far more expensive than continuous glucose monitoring during pregnancy. These results should influence clinical practice so that all women with type 1 diabetes have the best possible chance of having a healthy baby.”
The results were published in the Lancet journal and were also presented at the European Association for the Study of Diabetes (EASD) 2016 Annual Meeting.
To read the study, click here.