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Diabetes in pregnancy


Screening and diagnosis

Evaluation of the impact of universal testing for gestational diabetes mellitus on maternal and neonatal health outcomes: A retrospective analysis

This retrospective six-year analysis of birth data from Bradford Royal Infirmary, United Kingdom, shows that universally offering an oral glucose tolerance test was associated with increased identification of women with gestational diabetes mellitus.

Summary points
  • Treatment of gestational diabetes mellitus (GDM) seems to improve perinatal outcomes, although the relative effectiveness of different strategies for identifying women with GDM is less clear.
  • This paper describes a retrospective evaluation of the impact on maternal and neonatal outcomes of a change in policy from selective risk factor-based offering to universal offering of an oral glucose tolerance test (OGTT) to identify women with GDM.
  • The proportion of the whole obstetric population diagnosed with GDM increased almost fourfold following universal offering of an OGTT compared to selective offering of an OGTT.
  • The proportion identified as having severe hyperglycemia doubled following the change in policy.
  • However, the population case-detection rate (for both GDM and severe hyperglycemia in those with GDM) reduced by 50-60% following universal offering of a diagnostic OGTT, reflecting an increase in those offered the test who were not at risk.
  • Offering all women diagnostic testing was also associated with improved neonatal outcomes in women identified with GDM.

Farrar D et al. BMC Pregnancy Childbirth 2014; 14: 317. doi: 10.1186/1471-2393-14-317

Gestational diabetes testing: Making sense of the controversy

This review describes the current state of knowledge about the impact of hyperglycemia in pregnancy and discusses the various approaches to testing for gestational diabetes mellitus and the evidence to support them.

Summary points
  • There continues to be controversy over exactly who, when, and how to test for gestational diabetes mellitus (GDM), with various professional organizations and experts in the field suggesting different strategies.
  • Controversies in GDM testing include one-step versus two-step testing, Carpenter-Coustan criteria versus National Diabetes Data Group thresholds, universal versus risk-based screening, whether to screen early in pregnancy, management of a single abnormal value on a 3-hour glucose tolerance test, and the use of hemoglobin A1c for screening.
  • GDM testing controversies are centered on different providers’ preferences for sensitivity or specificity, which are likely to be influenced by provider experience, patient populations, and resources.
  • The approach to GDM testing should be the most sensitive testing strategy feasible for a given woman in a given practice.

Salmeen K. J Midwifery Women's Health 2016; 61: 203–209. doi: 10.1111/jmwh.12377

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