Aim: To examine ongoing trends in the numbers of GDM referrals to Canberra Health Services Diabetes in Pregnancy Service, the numbers requiring insulin therapy, the subset needing hospital transfer as a result and the demographic and physical characteristics of this cohort.
Methods: Patient information including pre-pregnancy BMI, weight and OGTT result are recorded at the time of the GDM patient appointment. For the period 1 Jan 2017 to 31 March 2019 this data is analysed. One thousand (interim sample) patient files were also reviewed for additional information such as country of birth, ethnicity, need for and type of insulin and planned and actual hospital for delivery.
Results: On average, 232 women per quarter received GDM education in 2017, increasing to 250 in 2018. The first quarter of 2019 surged to 291. Group education for starting insulin was provided to 60 women in quarter 1 of 2017, 94 in Q2 then this ranged from 96-121 per quarter until the end of 2018, and 140 in Q1 of 2019. At least 20 patients per quarter needed to transfer from secondary to tertiary care for delivery due to having started insulin.
Forty-five percent had a family history of diabetes, 16% had GDM in a prior pregnancy and 41% started on insulin. Of those that started insulin 53 % were for basal, 31% basal bolus and 10% bolus. 53% of the cohort were born in Australia, with 47% from high risk ethnicity groups.
The average BMI in the whole cohort was 28 kg/m2, with 31% BMI>30. Diagnosis based on fasting BGL alone increased from 32% in 2017 to 36% in 2018. The number diagnosed solely on the 1 hour figure on OGTT is constant at about 12% in 2017-18.
Conclusions: The number of women referred for GDM and consequently the number requiring insulin therapy continues to grow. Risk factors identified for these women are consistent with other GDM populations.