Closed-Loop Insulin Systems Show Promise for Pregnant Women With Type 1 Diabetes

A randomized clinical trial published in 2025 compared closed-loop insulin systems to standard care in 91 pregnant women with Type 1 diabetes across Canada and Australia. Closed-loop systems use a continuous glucose monitor, insulin pump, and computer algorithm to automatically adjust insulin delivery.

Women using closed-loop systems spent an average of 65.4% of the time between 16 and 34 weeks of pregnancy in the pregnancy-specific glucose target range (63–140 mg/dL). Women using standard insulin pumps or daily injections spent only 50.3% of the time in that range. This 15-percentage-point difference is substantial and statistically significant.

The trial included 88 women in the final analysis with an average age of 31.7 years. Both groups had similar starting hemoglobin A1c levels (a measure of long-term blood sugar control), averaging 7.4%.

Hyperglycemia—high blood sugar—during pregnancy occurs in about 50% of pregnant women with Type 1 diabetes and carries real risks. Poor glycemic control during pregnancy increases the chance of pregnancy complications, birth defects, and problems for the newborn.

This is why pregnancy-specific blood sugar targets are tighter than what many people with Type 1 diabetes aim for at other times. The goal range of 63–140 mg/dL is designed to protect fetal health while avoiding low blood sugar episodes that could harm the mother.

Medical experts emphasize that the best time to optimize blood sugar is before pregnancy. Preconception care—planning ahead and achieving strict glycemic goals—reduces the risk of birth defects and other adverse outcomes. Yet research shows that relatively few people with Type 1 diabetes receive this kind of early planning.

Joint guidelines from the Endocrine Society and European Society of Endocrinology, published in 2025, emphasize that reducing high blood sugar before and during pregnancy can lower risks for both mother and baby. The guidelines highlight that newer technologies like closed-loop systems show promise in helping reach these important goals.

Beyond blood sugar, the guidelines note that overall health matters too—including nutrition, weight management, and insulin-sensitizing medications. Pregnancy planning for people with Type 1 diabetes is not just about one number; it involves coordinated care across multiple areas.

Closed-loop systems are continuing to be studied in various real-world situations. Current research is exploring how these systems work during religious fasting and in different age groups, expanding our understanding of when and how they help most.

If you have Type 1 diabetes and are planning pregnancy, or are already pregnant, this research suggests that discussing closed-loop insulin systems with your care team may be worthwhile. These systems appear to help maintain steadier blood sugar during the critical pregnancy months.

The evidence supports the importance of starting the conversation about pregnancy well before it happens. Working with your healthcare provider to achieve good blood sugar control before conception gives you and your baby the best possible foundation.

Every pregnancy is unique, and the right approach depends on your individual circumstances. Talk with your doctor or diabetes care team about what tools and strategies make sense for your situation.

Origin: YouTube / Juicebox Podcast (Video report). Evidence: Video report, corroborated with 5 indexed studies. Type1Cure is an information and intelligence hub, not a medical advice service. This article summarizes published research and does not provide diagnosis, treatment, or personal medical guidance. Always talk to your own care team before changing anything about your Type 1 diabetes management.