Introduction:
The adoption of altered GDM diagnostic criteria, along with concomitant rising rates of advanced maternal age and obesity, have changed the demography of women with gestational diabetes mellitus (GDM) in the antenatal clinic. Furthermore, the use of metformin has become routine and at the discretion of the attending clinicians. As part of a large retrospective audit of women managed at RNSH between 2010 to the present, we reviewed the therapeutic choices for glycaemic management in the first 91 patients included.
Results:
Ninety one patients, age 32.5±4 years, parity 1.7±0.9, BMI 25.5±5.0kg/m2 and HbA1c 5.2±0.6% form the basis of the current report. Forty-one patients (45%) were managed with diet and lifestyle measures alone, 9 (9.8%) with metformin alone, 33 (36.3 %) with insulin and 8 (7.2%) with combination metformin/insulin. Women who were taking insulin (p<0.005) had higher HbA1c at the diagnosis (p<0.005) and were older (p<0.005); however, after adjusting for BMI these relationships was no longer significant. Analysis of the metformin versus metformin in combination with insulin groups found that metformin/insulin women were older than those on metformin alone (35.3 vs.31.1years, p<0.005) and women with higher HbA1c at diagnosis were more likely to require combination metformin/insulin as compared to those on metformin alone (p<0.001). There was a greater rate of caesarean sections in women taking metformin/insulin versus those on metformin alone (p<0.005).
Implications:
Preliminary data suggests that women who were prescribed metformin in combination with insulin were older and had a higher BMI and HbA1c at GDM diagnosis. This audit provides valuable insight into the characteristics of the current GDM population in a large tertiary referral hospital and the use of metformin in this population.