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10-03-2021 | Diabetes | News | Article

Two-step screening may be best for gestational diabetes

Author: Eleanor McDermid

medwireNews: Single-step screening for gestational diabetes makes twice the number of diagnoses of the two-step approach without resulting in better outcomes for women and infants, shows the randomized ScreenR2GDM trial.

The one-step approach, as recommended by the International Association of the Diabetes and Pregnancy Study Groups (IADPSG), was based on a single 2-hour fasting oral glucose tolerance test (OGTT). The two-step approach comprised a 1-hour nonfasting OGTT followed by a confirmatory 3-hour fasting OGTT for women with an intermediate glucose level of at least 130–140 mg/dL (7.2–7.8 mmol/L, depending on the study site) but below 200 mg/dL (11.1 mmol/L).

As reported in The New England Journal of Medicine, 23,792 pregnant women were randomly assigned to undergo one-step or two-step screening in a pragmatic, nonblinded trial.

Of these women, 66% and 92%, respectively, underwent the assigned approach; the researchers attribute this imbalance to providers’ “efforts to ensure screening by conducting the nonfasting two-step glucose challenge test at a prenatal visit.”

The one-step approach resulted in 16.5% of women receiving a gestational diabetes diagnosis, significantly more than the 8.5% who were diagnosed as such with the two-step approach, report Teresa Hillier (Kaiser Permanente Northwest, Portland, Oregon, USA) and study co-authors.

Despite this, there were no significant differences between the groups for the other primary outcomes. Specifically, 8.9% versus 9.2% of the one-step and two-step groups, respectively, had infants that were large for gestational age, and 3.1% and 3.0% had adverse perinatal outcomes such as stillbirth, neonatal death, and birth-related injuries.

A corresponding 13.6% and 13.5% had gestational hypertension or preeclampsia, while 24.0% and 24.6% of the one-step and two-step groups, respectively, required cesarean section.

The need for insulin or oral hypoglycemic treatment during pregnancy was similar in both groups, at 42.6% for women in the one-step group and 45.6% for those in the two-step group.

Writing in a linked editorial, Brian Casey (University of Alabama, Birmingham, USA) says the trial “provides robust evidence” that the single-step approach “resulted in the detection of gestational diabetes in almost one in five pregnant women, with no apparent maternal or perinatal benefit overall.”

He notes that “the potential long-term benefits of increased diagnoses of gestational diabetes – such as the identification of more women at high risk for subsequent diabetes who might benefit from risk-reduction strategies – were not addressed by the trial.”

Nevertheless, Casey concludes that “the perinatal benefits of the diagnosis of gestational diabetes with the use of the IADPSG single-step approach appear to be insufficient to justify the associated patient and health care costs of broadening the diagnosis.”

He adds: “Refocusing attention on interventions in women who are at risk for the development of diabetes is more likely to yield substantive benefits.”

medwireNews is an independent medical news service provided by Springer Healthcare Ltd. © 2021 Springer Healthcare Ltd, part of the Springer Nature Group

N Engl J Med 2021; 384: 895–904
N Engl J Med 2021; 384: 965–966

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