News & Research

Effectiveness of continuous glucose monitoring in pregnant women with diabetes: randomized clinical trial, by Helen R. Murphy and colleagues. British Medical Journal Published electronically ahead of print, 2008

What is the problem and what is known about it so far?

Improved care of pregnant women with diabetes has reduced the risks of unborn infant death (stillbirth) and death of the mother during delivery. However, pregnant diabetic women are still very likely to have overly large babies, which can cause problems for both the women and their infants. Although good pre-pregnancy care is key to controlling blood glucose during early pregnancy, the problem of overly large babies seems to be linked to high blood glucose levels in late pregnancy. New strategies are needed to improve glucose control during the final months of pregnancy.

Why did researchers do this particular study?

The researchers wanted to find out whether using a continuous glucose monitoring (CGM) device would help pregnant diabetic women reduce their risk of having overly large babies.

Who was studied?

The study included 71 pregnant women with either type 1 or type 2 diabetes in the United Kingdom.

How was the study done?

The women were divided into two groups: one receiving standard pregnancy care, and the other receiving standard care plus CGM every 4 to 6 weeks. CGM was used as an educational tool to help doctors and patients make decisions about diabetes management. The researchers measured A1C for all of the women every 4 weeks during the second and third trimesters of pregnancy. They also tracked babies' birth weights and the births of overly large babies

What did the researchers find?

Women whose care included CGM had lower A1C levels in late pregnancy, their babies had lower average birth weights, and their risk of delivering an overly large baby was lower than that of women whose care did not include CGM.

What were the limitations of the study?

The women in this study were mostly white Europeans, so the findings may not hold true for women of other cultures and ethnic backgrounds. Although steps were taken to ensure that all women received the same level of care except for CGM, it is possible that bias may have affected the quality of clinical care delivered to the two groups. It is also possible that differences in the characteristics of the women, such as their duration of diabetes, may have influenced the results. Finally, the study was small; larger studies will be needed to learn more about the costs and benefits of using CGM during pregnancy.

What are the implications of the study?

New technologies such as CGM may help pregnant women with diabetes improve their blood glucose control and avoid complications for themselves and their infants.

FOR MORE INFORMATION

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How to Treat Gestational Diabetes

Gestational Diabetes: What to Expect