Poster Presentation Australasian Diabetes in Pregnancy Society Annual Scientific Meeting 2019

The usefulness (or uselessness) of HbA1c for women tested early in pregnancy for GDM. (#57)

Michele Martin 1 , Alison Webb 1 , Robert G Moses 1
  1. Illawarra Shoalhaven Diabetes Service, Wollongong, NSW, Australia

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ADIPS recommends that “women with risk factors for hyperglycaemia in pregnancy should be tested early in pregnancy”. Alternative testing with either a GTT or an HbA1c can be considered. For this reason, a fasting glucose could be carried out at the first available antenatal opportunity. While ideally this should be confined to women with risk factors, many women with no acknowledged risk factors are also being tested. For a variety of reasons, an HbA1c estimation has been suggested as an alternative test for diagnosis. While this may be useful in areas where there is a high rate of undiagnosed HIP, its usefulness and practicality for the general obstetric population has not been established.

 

Aim. The aim of this study was to test the HbA1c level in women diagnosed with a fasting glucose level before 20 weeks gestation in order to determine if this would have been a useful alternative.

 

Methods. Most women with GDM diagnosed in the Wollongong area are referred to the Diabetes Centre for education, dietary advice and ongoing supervision – approximately 700+ each year. Most of the nurse diabetes educators attached to the Centre rotate through the GDM clinics. The data herein reported is a personal series of one educator (MM). Fifty consecutive women with GDM, a singleton pregnancy and presenting after testing before 20 weeks gestation seen by MM between 1/2018 and 2/2019 had an HbA1c test carried out.

 

Results

Of the 50 women considered, a 2-hour GTT had only been conducted in 10. The results (mean ± 2SD) fasting glucose was 5.4 ± 0.6 mmol/L, age 31.6 ± 9.6 years and HbA1c 5.2 ± 0.5%.

 

Conclusion.

For all the women with GDM, the HbA1c was normal and cannot be considered as an alternative to glucose testing.