Blood Ketone Testing More Effective for Gestational Diabetes Monitoring: Study

Women with gestational diabetes mellitus (GDM) are frequently asked to check their ketone levels by measuring ketonuria before breakfast. However, ketosis could be present even before lunch and dinner. Furthermore, blood ketone measurement could be a more accurate test.

The aim was to evaluate the effect of a blood ketone intensive measurement in the detection of ketosis in women with gestational diabetes mellitus with a negative urinary ketone test. This was a single center, observational, prospective study involving consecutive women with gestational diabetes mellitus. Only women with negative fasting urinary ketone tests were included. During the same gestational weeks (weeks 30–32), all women were asked to perform a blood ketone test before their main meals. Ketosis was defined as the presence for at least 25% of the time of fasting blood ketone levels > 0.1 mmol/L and > 0.2 mmol/L before lunch and dinner.

Results: Overall, a total of 101 women (mean age 34.7 ± 4.8 years, prepregnancy BMI 28.2 ± 5.2 kg/m2) were studied. Blood ketones were present in 37.6% of the cases before breakfast, 13.9% before lunch, and 11.9% before dinner. Women with at least one daily presence of blood ketones composed 40.6% of the sample. Presence of fasting blood ketones was correlated with ketone presence before lunch (r = 0.63, p < 0.0001) and before dinner (r = 0.55, p < 0.0001) and with mean glucose levels (r = 0.23, p = 0.02) 1 h after breakfast.

Blood ketone testing in women with gestational diabetes mellitus can detect a larger number of ketosis episodes than a urinary ketone test. Intensive blood ketone measurement should be recommended to women with gestational diabetes mellitus.

Reference:

Pintaudi, B., Giunta, L., Di Vieste, G. et al. Evaluation of ketone intensive measurement in women with gestational diabetes (EVOKING) study. Hormones (2025). https://doi.org/10.1007/s42000-025-00663-1