The results indicated that metformin is comparable to insulin for glycemic control and pregnancy outcomes in women with gestational diabetes.
Previously, clinical guidelines did not recommend oral hypoglycemic agents during pregnancy. Now, with a growing body of evidence supporting their safety and efficacy in the management of gestational diabetes, guidelines have begun to recommend metformin as the primary drug choice for patients with gestational diabetes. Researchers aimed to assess the clinical impact of this shift to a metformin-based approach. The study included 264 participants with gestational diabetes who were seen at a single clinic prior to a Metformin First protocol (January to July 2015) and after its implementation (January to September 2016). With the Metformin First protocol, all patients requiring the management of gestational diabetes were offered metformin as a first option.
The researchers conducted a retrospective chart review and administered a prospective participant survey. They compared responses to a similar survey from 2013 as a historical control.
Of the patients, 90 were seen in the pre-Metformin First period and 174 were seen in the post-Metformin First period. The researchers did not find any significant differences in the rate of pregnancy complications between the two groups, including obstructed labor, infants born large for gestational age, neonatal intensive care unit admission, and infant hypoglycemia. In addition, blood glucose control was comparable and satisfactory in both groups.
Of 65 patients initially started on metformin, 18 (28%) were provided supplemental insulin therapy and 9 (14%) experienced gastrointestinal side effects from metformin use. Despite this, the overall percentage of patients started on insulin dropped significantly from 33% in 2015 to 17% in 2016 (P =.003).
Following implementation of the Metformin First protocol, the results indicated an increase in patient satisfaction scores, which rose from 4.3 out of 5 in 2013 to 4.68 out of 5 in 2016 (P =.014).
The researchers noted that the allocation of metformin was not blinded or randomly assigned, which may have introduced bias into the study results.
“The outlined [Metformin First] protocol may provide a framework for future adoption of metformin use into routine clinical practice for management of [gestational diabetes],” the researchers wrote.
Kumar R, Lowe J, Thompson-Hutchison F, et al. Implementation and evaluation of the Metformin First protocol for management of gestational diabetes [published online June 26, 2019]. Can J Diabetes. doi:10.1016/j.jcjd.2019.06.005