Temporary changes to gestational diabetes mellitus (GDM) testing procedures in pregnancy have been introduced to support social distancing and minimise blood collection time during the COVID-19 pandemic.
The new antenatal and postnatal testing advice is provided by the Australasian Diabetes in Pregnancy Society (ADIPS), the Australian Diabetes Society (ADS), the Australian Diabetes Educators Association (ADEA), and Diabetes Australia (DA).
The new guidance recommends that all pregnant women be screened for risk factors such as BMI,> 30, maternal age ≥ 40 years and family history of diabetes mellitus. Women with risk factors should have first trimester HbA1c, whereas those without risk factors could fasting FBG checked at 24–28 weeks gestation or if there are clinical concerns after first trimester
OGTT is not required if FBG is ≤ 4.6 mmol/L or ≥ 5.1 mmol/L.
GDM diagnosis is based on either HbA1c in first trimester only ≥ 41 mmol/mol (or 5.9%) or OGTT with one or more of: fasting ≥ 5.1 mmol/L, 1 hour ≥ 10 mmol/L and 2 hour ≥ 8.5 mmol/L.
The advice for post-partum testing if gestational diabetes was diagnosed is that women should to delay the Glucose Tolerance Test (GTT) for 6-12 months.
Continued self-blood glucose monitoring after pregnancy may be appropriate in women at high risk of T2D (e.g. HbA1c ≥6% in pregnancy, total daily dose insulin >150 units). Performing an HbA1c at 4-6 months post-partum may also be appropriate.
“These changes are intended to limit the number of women attending pathology collection centres and the amount of time spent at pathology collection centres,” the advice states.
But it may be appropriate to continue the current procedures In some high-risk populations if appropriate social distancing can be ensured, they add.
“It is acknowledged that changes to the GDM testing procedure will likely miss some women who otherwise would have been diagnosed with gestational diabetes. This testing procedure still aims to identify the highest risk gestational diabetes,” they conclude.