An artificial pancreas has for the first time shown it can keep even overnight blood glucose levels normal in a small group of pregnant women with Type 1 diabetes, raising hopes that the new development will significantly reduce stillbirths, abnormalities, and deaths associated with this type of diabetes.

You can read how the researchers of the Diabetes UK sponsored study, led by Dr Helen Murphy of Cambridge University, UK, tested the “closed-loop insulin delivery system” in the February print issue of Diabetes Care, also available online from early January.

Murphy and colleagues evaluated the performance of their artificial pancreas in ten pregnant women with Type 1 diabetes and found it was able automatically to give them the correct amount of insulin at the right time to keep their blood glucose within normal levels.

The trial also showed the device successfully prevented nocturnal hypoglycaemia (low blood glucose at night) in early and also in late pregnancy.

The researchers said this was the first time an artificial pancreas had been used in pregnancy.

The device has two parts: a continuous glucose monitor and an insulin pump, both of which are already used separately by many people with Type 1 diabetes.

Earlier studies involving children with Type 1 diabetes showed that an artificial pancreas made from bringing these two devices together was successful in controlling glucose levels but this is the first to show success in pregnant women with Type 1 diabetes.

Two thirds of pregnant women with pre-existing diabetes have Type 1 diabetes.

Diabetes is a particular problem in pregnancy because the hormone changes of the condition make it difficult to keep tight control of blood glucose, especially at night.

Babies born to mothers with diabetes are five times more likely to be stillborn, three times more likely to die within a few months of birth, and twice as likely to have a major abnormality than babies born to mothers who do not have the disease.

Murphy told the press that high blood glucose increases the risk of congenital abnormality, stillbirth, neonatal death, preterm delivery, macrosomia (oversized babies) and neonatal admission.

Low blood glucose (hypoglycemia) in pregnancy is also a major cause of death among pregnant women.

Murphy said:

“For women with Type 1 diabetes, self-management is particularly challenging during pregnancy due to physiological and hormonal changes.”

“Previous studies indicate that pregnant women with the condition spend an average of ten hours a day with glucose levels outside the recommended target,” she added, saying it was “very promising” to discover an artificial pancreas can help these women keep their glucose near-normal during pregnancy.

Dr Iain Frame, Director of Research at Diabetes UK, said the study was a “fantastic example” of how current technology like insulin pumps and continuous glucose monitors can be adapted to help even more people with diabetes.

“Although early days, this exciting area of research, funded by our donors, has huge potential to make pregnancy much safer for women with Type 1 diabetes, and their babies,” said Frame.

“We now need to see an extension of this study, one which tests larger numbers of women, and then take it out of the hospital and in to the home setting,” he added.

“Closed-Loop Insulin Delivery During Pregnancy Complicated by Type 1 Diabetes.”
Helen R. Murphy, Daniela Elleri, Janet M. Allen, Julie Harris, David Simmons, Gerry Rayman, Rosemary Temple, David B. Dunger, Ahmad Haidar, Marianna Nodale, Malgorzata E. Wilinska, and Roman Hovorka.
Diabetes Care, February 2011 34:406-411; published ahead of print 7 January 2011.
DOI:10.2337/dc10-1796

Additional source: Diabetes UK (News release 31 Jan 2011).

Written by: Catharine Paddock, PhD