Counterpoint: Selective Screening for Gestational Diabetes Mellitus
- Howard Berger, MD1 and
- Mathew Sermer, MD2
- 1Department of Obstetrics and Gynecology, St. Michael's Hospital, University of Toronto, Toronto, Canada;
- 2Department of Obstetrics and Gynecology, Mount Sinai Hospital, University of Toronto, Toronto, Canada.
- Corresponding author: Mathew Sermer, msermer{at}mtsinai.on.ca.
Gestational diabetes mellitus (GDM), defined as carbohydrate intolerance first diagnosed during pregnancy (1), is a common medical complication of pregnancy, affecting 1.1–14.3% of pregnant women depending on the ethnic and clinical characteristics of the population and the diagnostic test employed (2). Ever since O'Sullivan and Mahan (3) published their criteria for diagnosis of GDM using a 100-g oral glucose tolerance test (GTT), clinicians worldwide have been struggling to determine whether screening for GDM should be offered routinely in pregnancy and, if so, the optimal method of screening. There have been no adequately designed randomized controlled trials to answer the question of whether screening for GDM is both beneficial and cost effective, leading to a wide variance in screening practices worldwide. The Australian Carbohydrate Intolerance Study in Pregnant Women (ACHOIS), a multicenter randomized controlled trial of GDM treatment versus routine prenatal care, found a reduction in a composite of severe perinatal outcomes in the treatment group compared with a control group receiving routine prenatal care (4). Although it was not a trial of screening, its results have convinced many practitioners to adopt some type of screening for GDM because logically, in order to treat GDM (an asymptomatic entity), one must first screen for it. Recently, the U.S. Preventive Services Task Force (USPSTF), in an update to its policy statement on screening for GDM, recognized that treatment of GDM after 24 weeks of gestation improves some maternal and neonatal outcomes but, conversely, also stated that there is still insufficient evidence to support screening of all pregnant women either before or after 24 weeks of gestation (5). Despite this, most clinicians use some method of screening for GDM.
Ideally, the chosen screening protocol should identify subjects at maximal risk of adverse pregnancy outcomes who would most benefit from intensified management and surveillance, while …
