Background: Gestational diabetes mellitus (GDM) is a common disorder associated with both maternal and fetal complications. Treatment for GDM requires lifestyle modification, as well as insulin and oral anti-diabetes medications to prevent unwarranted fetal and maternal outcomes. Objective: To determine the feto-maternal outcomes of GDM patients treated with either metformin-monotherapy, insulin- monotherapy, and with insulin plus metformin (combination) therapy in a private tertiary hospital in Metro Manila. Methods: This is a retrospective cohort study involving 209 GDM patients admitted from January 2017 to December 2019. Census and chart reviews were done for demographic and clinical data. These were divided into 3 groups: metformin-monotherapy, insulin-monotherapy, and combination treated groups. Analysis of Variance was used to compare the average capillary blood glucose (CBG) levels of patients. Chi-square and Fisher’s Exact tests were used for nonparametric data. Results: Birthweight was significant across all groups: metformin-monotherapy group highest with large-for-gestational- age (LGA) at 25%, small-for-gestational-age (SGA) highest on the insulin-monotherapy group (11.3%) and appropriate-for- gestational-age (AGA) highest in the combination therapy group (84.6%). Age of gestation (AOG) at delivery (p=0.005), maternal CBG during labor (p=0.007), and chronic hypertension (p=0.001) were statistically significant across all groups. Multiple comparisons showed the following statistically significant results as well: chronic hypertension between metformin and combination group (p <0.01), AOG during delivery between metformin vs insulin group (p=0.004), maternal CBGs during labor between metformin vs insulin group (p=0.022), and insulin vs combination treatment group (p=0.029). Average maternal CBG levels were also showed statistically significant difference between the metformin vs insulin group (p=0.029). Conclusion Metformin may be used in controlling CBG levels in GDM patients. Although metformin may be comparable to insulin, more long-term studies need to be done to determine its long-term effects on neonates.
Diabetes, Gestational