Hybrid Closed-Loop Pumps in Pregnancy: What a New Study Shows

Researchers compared pregnancy outcomes and blood sugar control in 154 women with Type 1 diabetes who started prenatal care between 2022 and 2025. About two-thirds of the women intended to use hybrid closed-loop (HCL) pumps—automated devices that adjust insulin delivery based on real-time glucose readings. The remaining women used sensor-augmented pump therapy (SAPT), a more manual approach where the person makes insulin adjustments based on sensor data.

The study was unique because it examined off-label use of hybrid closed-loop pumps during pregnancy. In the United States, most hybrid closed-loop systems don't have pregnancy-specific algorithms, so women who use them during pregnancy are doing so without official approval for that use.

Women using hybrid closed-loop pumps had babies that weighed, on average, about 272 grams (roughly 9.5 ounces) more than babies born to mothers using traditional sensor-augmented pumps. The HCL group's babies averaged 3,640 grams (about 8 pounds), while the SAPT group's babies averaged 3,430 grams (about 7.5 pounds).

In the week before delivery, women using hybrid closed-loop pumps had a mean glucose level of 150 mg/dL compared to 145 mg/dL in the sensor-augmented pump group. This 5 mg/dL difference was small, though it reached statistical significance in the analysis.

When researchers examined common pregnancy complications—including preeclampsia, cesarean delivery, preterm birth, and neonatal intensive care unit admission—they found no significant differences between the two groups. Rates of newborn complications like low blood sugar, jaundice, and respiratory distress syndrome were also similar.

This is an important finding because it suggests that using a hybrid closed-loop pump without a pregnancy-specific algorithm did not increase the risk of these serious outcomes, though it also doesn't prove that HCL use is completely equivalent to traditional methods.

The study provides some reassurance for pregnant women with Type 1 diabetes who choose to use hybrid closed-loop pumps despite the lack of pregnancy-specific approval. The similar complication rates between groups suggest these devices may be used safely during pregnancy, though blood sugar patterns were slightly different.

However, this was a single-center study of 154 women, so the findings need confirmation through larger, multi-center studies. The study also only looked at outcomes through the week before delivery, not long-term effects on infant health. Women considering hybrid closed-loop pumps during pregnancy should discuss the pros and cons with their diabetes care team, who can help weigh the potential benefits and uncertainties for their individual situation.

Source: Pregnancy (Hoboken, N.J.). Evidence type: PubMed indexed literature. 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.