Closed-Loop Insulin Delivery During Pregnancy Improves Glucose Control Interview with:
Professor Helen Murphy
Dr Zoe Stewart
Institute of Metabolic Science
University of Cambridge What is the background for this study?

Response: Controlling blood glucose levels is a daily challenge for people with Type 1 diabetes and is particularly crucial during pregnancy. Previous research shows that women with type 1 diabetes spend only 12 hours per day within the recommended glucose target levels, leading to increased rates of complications including preterm delivery and large for gestational age infants. National surveys show that one in two babies suffer complications related to type 1 diabetes in the mother.

The hormonal changes that occur in pregnancy make it difficult for women to predict the best insulin doses for every meal and overnight. Too much insulin causes low glucose levels harmful for the mother and too little causes problems for the developing baby. The artificial pancreas automates the insulin delivery giving better glucose control than we can achieve with currently available treatments. Previous studies show that the closed-loop system also known as artificial pancreas can be used safely in children and adults and our study aimed to investigate whether or not it was helpful for women with type1 diabetes during pregnancy. What are the main findings?

Response: Our study found that the closed-loop artificial pancreas was associated with a 25% improvement in overnight glucose control compared with the current best available treatment – a sensor augmented pump which combines a continuous glucose monitor and an insulin pump. It did this safely without increasing hypoglycaemia suggesting that automated insulin delivery is safer and more effective than standard patient directed insulin delivery. In an extension study 14/16 women choose to continue closed-loop wearing it during hospital admission and before and after giving birth. This suggests that the system can cope well with a wide range of physiological challenges. What should readers take away from your report?

Response: Readers should be aware that new automated insulin delivery technologies may help more pregnant women with type 1 diabetes to safely achieve tighter glucose control than currently available treatments. In particular women with low numeracy/health literacy may struggle with the complex and changing insulin requirements of pregnancy – these women are currently least likely to achieve safe control and may benefit most from new automated systems. What recommendations do you have for future research as a result of this study?

Response: This research is still in its early stages and larger studies involving more women from different centres using the closed-loop system throughout pregnancy are now needed to understand whether the exciting preliminary results will translate into better health outcomes for mothers and their babies. Is there anything else you would like to add?

Response: We would like to thank all the study participants for their contribution to this research. Thank you for your contribution to the community.


Closed-Loop Insulin Delivery during Pregnancy in Women with Type 1 Diabetes

Zoe A. Stewart, M.D., Malgorzata E. Wilinska, Ph.D., Sara Hartnell, B.Sc., Rosemary C. Temple, M.D., Gerry Rayman, M.D., Katharine P. Stanley, M.D., David Simmons, M.D., Graham R. Law, Ph.D., Eleanor M. Scott, M.D., Roman Hovorka, Ph.D., and Helen R. Murphy, M.D.

N Engl J Med 2016; 375:644-654
August 18, 2016

DOI: 10.1056/NEJMoa1602494

Note: Content is Not intended as medical advice. Please consult your health care provider regarding your specific medical condition and questions.

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Last Updated on August 19, 2016 by Marie Benz MD FAAD