Prediabetes and pregnancy: Early pregnancy HbA1c identifies Australian Aboriginal women with high-risk of gestational diabetes mellitus and adverse perinatal outcomes

Emma L Jamieson; Erica P Spry; Andrew B Kirke; Emma Griffiths; Cynthia Porter; Carly Roxburgh; Sally Singleton; Kylie Sterry; David N Atkinson; Julia V Marley

doi:10.1016/j.diabres.2021.108868

Prediabetes and pregnancy: Early pregnancy HbA_1c identifies Australian Aboriginal women with high-risk of gestational diabetes mellitus and adverse perinatal outcomes

Diabetes Res Clin Pract. 2021 Jun:176:108868. doi: 10.1016/j.diabres.2021.108868. Epub 2021 May 21.

Authors

Affiliations

¹ The University of Western Australia, Medical School, The Rural Clinical School of Western Australia, Building 3 Edith Cowan University, Robertson Drive, PO Box 412, Bunbury, WA 6230, Australia.
² The University of Western Australia, Medical School, The Rural Clinical School of Western Australia, 12 Napier Terrace, PO Box 1377, Broome, WA 6725, Australia; Kimberley Aboriginal Medical Services, 12 Napier Terrace, Broome, WA 6725, Australia.
³ The University of Western Australia, Medical School, The Rural Clinical School of Western Australia, 12 Napier Terrace, PO Box 1377, Broome, WA 6725, Australia.
⁴ Geraldton Regional Aboriginal Medical Service, Rifle Range Road, Rangeway, WA 6530, Australia.
⁵ The University of Western Australia, Medical School, The Rural Clinical School of Western Australia, 31 Stirling Terrace, Albany, WA 6330, Australia.
⁶ The University of Western Australia, Medical School, The Rural Clinical School of Western Australia, St Alban's Road (rear Kalgoorlie Hospital), Kalgoorlie, WA 6433, Australia.
⁷ The University of Western Australia, Medical School, The Rural Clinical School of Western Australia, 12 Napier Terrace, PO Box 1377, Broome, WA 6725, Australia; Kimberley Aboriginal Medical Services, 12 Napier Terrace, Broome, WA 6725, Australia. Electronic address: julia.marley@rcswa.edu.au.

PMID: 34023341
DOI: 10.1016/j.diabres.2021.108868

Abstract

Aims: To assess whether early pregnancy HbA_1c can predict gestational diabetes mellitus (GDM) and adverse birth outcomes in Australian women.

Methods: Prospective study of 466 women without diabetes, aged ≥16-years at first antenatal presentation. Recruitment was from 27 primary healthcare sites in rural and remote Australia from 9-January 2015 to 31-May 2018. HbA_1c was measured with first antenatal investigations (<20-weeks gestation). Primary outcome measure was predictive value of HbA_1c for GDM, by routine 75 g oral glucose tolerance test (OGTT; ≥24-weeks gestation), and for large-for-gestational-age (LGA) newborn.

Results: Of 396 (129 Aboriginal) women with routine OGTT, 28.8% had GDM (24.0% Aboriginal). HbA_1c ≥5.6% (≥38 mmol/mol) was highly predictive (71.4%, 95% CI; 47.8-88.7%) for GDM in Aboriginal women, and in the total cohort increased risk for LGA newborn (RR 2.04, 95% CI; 1.03-4.01, P = 0.040). There were clear differences between Aboriginal and non-Aboriginal women: 16.3% v 5.2% (P < 0.001) had elevated HbA_1c whereas 12.4% v 29.6% (P < 0.001) developed hyperglycemia during pregnancy.

Conclusions: Early pregnancy HbA_1c ≥5.6% (≥38 mmol/mol) identifies Aboriginal women with apparent prediabetes and elevated risk of having an LGA newborn. Universal HbA_1c at first antenatal presentation could facilitate earlier management of hyperglycemia and improved perinatal outcome in this high-risk population.

Keywords: Gestational diabetes mellitus; Glycated hemoglobin; HbA(1c); Indigenous health; Prediabetes.

MeSH terms

Adolescent
Adult
Australia / ethnology
Cohort Studies
Diabetes, Gestational / blood
Diabetes, Gestational / diagnosis*
Diabetes, Gestational / ethnology
Diabetes, Gestational / etiology
Female
Gestational Age
Glucose Tolerance Test
Glycated Hemoglobin / analysis*
Glycated Hemoglobin / metabolism
Humans
Infant, Newborn
Male
Native Hawaiian or Other Pacific Islander* / ethnology
Prediabetic State / blood
Prediabetic State / complications
Prediabetic State / diagnosis*
Prediabetic State / ethnology
Pregnancy
Pregnancy Complications / blood
Pregnancy Complications / diagnosis
Pregnancy Complications / ethnology
Pregnancy Outcome* / ethnology
Pregnancy Trimester, First / blood
Prognosis
Prospective Studies
Risk Factors
Young Adult

Substances

Glycated Hemoglobin A