Gestational diabetes: Continuous glucose monitoring reduces risk of excessive birth weight

An international research team led by the Medical University of Vienna has shown that continuous glucose monitoring (CGM) in women with gestational diabetes can reduce the risk of a newborn with above-average birth weight. The study, published in the leading journal The Lancet Diabetes & Endocrinology, is the first multicenter randomized controlled trial to demonstrate the advantages of the digital method over conventional self-monitoring of blood glucose using finger pricks and opens up new perspectives for the targeted care of women with gestational diabetes.

The study included 375 women with gestational diabetes at four university centres: University Hospital Vienna, Charité – Universitätsmedizin Berlin, Jena University Hospital and Basel University Hospital. The participants were randomly assigned to either the study group with continuous real-time glucose monitoring (rt-CGM) or the group with intermittent self-monitoring of blood glucose via finger pricks (SMBG) and were cared for according to guideline-compliant treatment standards until delivery. Gestational diabetes can lead to excessive growth of the child, which can contribute to birth problems, but also to an early childhood predisposition to obesity and metabolic diseases. Early diagnosis and consistent treatment can significantly reduce this risk.

The evaluation of birth data in the study shows a clear advantage of continuous glucose monitoring: only four percent of women in the rt-CGM group gave birth to an above-average weight child (LGA = Large for Gestational Age), compared to ten percent in the control group. In addition, the average birth weight percentiles were lower in the rt-CGM group, indicating that the children of these women were less likely to grow excessively.

Blood sugar levels available at any time

"Continuous glucose monitoring via a sensor placed under the skin allows patients to check their blood sugar levels at any time. This enables them to make specific adjustments to their lifestyle or insulin therapy, which can have a positive impact on the course of their pregnancy," explains study leader Christian Göbl (Department of Obstetrics and Gynecology, MedUni Vienna/University Hospital Vienna). However, it was noticeable that in both study groups there were more newborns with below-average birth weight (small for gestational age, SGA). This could indicate that very strict sugar management could also influence the risk of insufficient foetal growth – and requires further investigation, according to the researchers.

In any case, our results suggest that real-time glucose monitoring systems can improve pregnancy care – especially for women who benefit from more intensive therapy," emphasises first author Tina Linder (Department of Obstetrics and Gynecology, MedUni Vienna/University Hospital Vienna). "At the same time, the optimal blood glucose target values still need to be precisely defined in order to avoid both overgrowth and undergrowth of the foetus."

Reference:

Linder, TinaKotzaeridi, Grammata et al, Glycaemic control and pregnancy outcomes with real-time continuous glucose monitoring in gestational diabetes (GRACE): an open-label, multicentre, multinational, randomised controlled trial, The Lancet Diabetes & Endocrinology, DOI: 10.1016/S2213-8587(25)00288-8