Poster Presentation Australian Diabetes in Pregnancy Society 2018

Ethnic inequities persist in screening for gestational diabetes in New Zealand despite implementation of national guidelines  (#118)

Elizabeth Lewis 1 , Manjula Ratnaweera 1 , Louise Wolmarans 1 , Jade A U Tamatea 1 , Ryan G Paul 1
  1. Waikato District Health Board, Hamilton

Background: Gestational diabetes mellitus (GDM) has important health implications for both the mother and child. Although Māori women are at greater risk of pre-existing diabetes or GDM during pregnancy than non-Māori women, screening rates for diabetes in pregnancy were lower in Māori women in 2013. To improve screening of GDM in all New Zealand women and to reduce this inequity, the Ministry of Health introduced national screening guidelines in 2014. Briefly, an HbA1c is recommended before 20-weeks gestation to detect undiagnosed diabetes (> 50 mmol/mol). If initial screening is negative, a 50 g oral polycose test (OPTT) or a 75 g oral glucose tolerance test (OGTT) is recommended at 24-28 weeks gestation.

Aims: To determine whether screening rates of GDM remain lower in Māori women than in non-Māori women in the Waikato region of New Zealand.

Method: Retrospective review of clinical records of all pregnant women with no known history of diabetes who delivered in the Waikato region from June - August 2017 (n = 807).

Results: Māori women (n = 259) were less likely than non-Māori women (n = 548) to have either an HbA1c performed before 20-weeks gestation (60.1% versus 68.0%; P < 0.05), or a screening OPTT or OGTT performed after 24-weeks gestation (64.8% versus 81.0%; P < 0.001). Screening at either time point was not affected by differences in age, social deprivation, or rural living. Only one woman (non-Māori) had pre-existing undiagnosed diabetes. The prevalence of GDM was unexpectedly lower in Māori women than in non-Māori women screened (3.9% versus 8.8%, P < 0.05).

Conclusion: Screening rates for GDM in both early and later pregnancy remain lower in Māori women than in non-Māori women, despite implementation of national guidelines. This inequity in screening likely explains, at least in part, why the prevalence of GDM in our study was lower in Māori women. Further work is required to achieve equity in screening for GDM in New Zealand.