Neonatal Birth Weight With Daily Compared With Every-Other-Day Glucose Monitoring in Gestational Diabetes Mellitus: A Randomized Controlled Trial.

Objective: To assess whether universal use of every-other-day glucose monitoring in patients with gestational diabetes mellitus (GDM) resulted in similar birth weights and medication use and was preferred by the patient compared with traditional daily glucose monitoring.

Methods: This was a noninferiority randomized controlled trial conducted at a single New York City hospital between April 2021 and May 2022. Patients with singleton pregnancies who were diagnosed with GDM after 20 weeks of gestation and had a minimum of 7 days of previous daily blood glucose testing were randomly assigned to test blood glucose values daily or every other day. The primary outcome was neonatal birth weight. We calculated a total sample size of 196 participants needed for noninferiority to be tested, assuming the mean birth weight in the every-other-day group, compared with the daily group, was no higher than the predefined noninferiority margin of 200 g (80% power and one-sided alpha of 0.05). Postrandomization characteristics, including blood glucose values and medication initiation and timing, were recorded. Satisfaction with treatment group was assessed using the validated Oxford Maternity Diabetes Treatment Satisfaction Questionnaire.

Results: A total of 197 patients were randomized: 98 in the daily group and 99 in the every-other-day group. Baseline characteristics were similar between groups. The mean neonatal birth weight was similar between groups (mean±SD 3,090±418 g among newborns in the daily group compared with 3,181±482 g among newborns in the every-other-day group). For the primary outcome, the every-other-day group was found to be noninferior to the daily group with an upper confidence limit for the mean difference in mean birth weight of 197 g, which was below the noninferiority margin of 200 g ( P =.046). Postrandomization, there were no significant differences in the number of patients who required medication, the gestational age at which medication was started, or the type of medication used. Average fasting and postprandial glucose values were similar between groups. There was an increase in adherence to treatment group in those randomized to every-other-day blood sugars, but no difference in patient satisfaction.

Conclusion: In patients with GDM, testing blood glucose values every other day was as effective as testing daily, without apparent effects on birth weight, medication initiation, or glucose control. Reduced frequency of blood glucose monitoring might help decrease the emotional, physical, and financial burden experienced by patients with GDM.

Clinical trial registration: ClinicalTrials.gov , NCT04857073.