Continuous glucose monitors help pregnant women with gestational diabetes lower their hemoglobin A1c levels by an average of 0.17 percentage points compared to traditional finger-prick methods, according to a research review published by the National Evidence-based Healthcare Collaborating Agency (NECA) on Oct. 24, 2024. While the wearable devices provide real-time tracking, researchers found no significant reduction in major birth complications.
Gestational diabetes occurs when placental hormones block the body’s insulin, raising blood sugar levels during pregnancy. According to NECA data, the prevalence of gestational diabetes among all pregnancies in South Korea climbed sharply from 7.6% in 2013 to 12.4% in 2023.
Evaluating Continuous Glucose Monitoring in Pregnancy
Traditional blood glucose management relies on self-monitoring via finger-prick blood tests. While common, the method requires frequent manual punctures and cannot provide 24-hour monitoring. Continuous glucose monitors use a thin sensor attached to the skin to track blood sugar in real time, eliminating the need for routine manual tests.
According to the NECA analysis of clinical studies, patients using continuous glucose monitors achieved hemoglobin A1c levels averaging 0.17 percentage points lower than those using standard self-monitoring methods. Hemoglobin A1c measures the proportion of red blood cells with glucose-bound hemoglobin, reflecting average blood sugar over the preceding two to three months. The blood-sugar reduction appeared most pronounced in expectant mothers with a body mass index (BMI) of 25 kg/m² or higher.
Limitations Regarding Birth Complications
Despite improvements in average blood sugar markers, the review found no clear evidence that continuous glucose monitors significantly decrease adverse birth outcomes. Researchers evaluated rates of macrosomia—infants weighing over 4 kg—neonatal hypoglycemia, neonatal intensive care unit admissions, gestational hypertension, and premature birth.
The analysis showed no statistically significant differences in these complications between continuous glucose monitor users and traditional monitoring groups. Standard average metrics like fasting and post-prandial blood sugar levels also showed no notable divergence between the cohorts.
“While we confirmed that continuous glucose monitors help lower hemoglobin A1c levels in gestational diabetes patients, there is insufficient evidence to prove that this improvement directly reduces complications,” said Kim Ji-min, a research fellow and lead study investigator at NECA.
NECA advises that clinicians and patients should determine device usage based on individual clinical needs, blood sugar control status, and obesity factors, noting that larger-scale studies are required to confirm the full clinical impact.
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