New guidelines for the diagnosis and management of gestational diabetes from the directorate general of health: A critical review

Abstract

The new guidelines from the Portuguese Directorate General of Health (DGH) for gestational diabetes (GD) recommend changes in the screening, treatment and follow-up of GD. We discuss the scientific basis for these guidelines and their poten- tial implications for improvements in health, costs, the use of health service resources and their potential impact on the new- ly diagnosed population of pregnant women. No references cited by the DGH support the diagnosis of GD based on fasting plasma glucose levels above 92 mg/dL at the first prenatal appointment. Using the new cutoff point for the diagnosis of GD for an oral glucose tolerance test performed between 24 and 28 weeks pregnancy results in a tenfold increase in the prevalence of GD, leading to increased allocation of health services resources for management and follow up. A review of the literature reveals no benefit from universal prenatal screening as opposed to selective screening of pregnant women with known risk factors (grade of Recommendation B and level of evidence 3A). Cost-effectiveness studies also favour selective screening over universal screening. Treatment of women newly diagnosed with GD has not shown a reduction in perinatal morbidity, as predicted by the HAPO study. Potential adverse effects of this approach have not been assessed. It would probably be wise to keep the new guideline on hold and return to the previous protocol of GD screening until more robust evidence supports changes.