There has been no consensus for screening methodology, diagnosis, and management of gestational diabetes mellitus (GDM). We aimed to evaluate routine practice for GDM management across the U.K., including postnatal care. Questionnaires were sent to all members of the Association of British Clinical Diabetologists. They were asked to describe how patients were screened for GDM, the diagnostic criteria, and subsequent management and clinical targets, as well as postnatal care. Centers that did not initially respond were followed up by personal communication. Regional variability trends were assessed by subdividing the U.K. into 10 regions and then analyzing the data with the StatXact χ2 test (version 4; Cytel Software, Cambridge, Massachusetts), which has the ability to evaluate associations in two-way tables where there are small frequencies. In addition to providing an indication whether there is a trend in the variability in practice across the U.K., comparing the responses from individual regions also provided an indirect validation surrogate.
The response rate averaged 46% nationally (35–67%). Most (85%) units had a joint clinic, regardless of the size. Most (82%) centers routinely screened for GDM, one-half doing so universally and one-half screening high-risk pregnancies only.
Screening tests, cut-off values, timings, and subsequent action varied widely. The first screening test to be used varied, with 40% using glycosuria, followed by random plasma glucose (28%), high-risk features (11%), and fasting plasma glucose (6%). Cut-off values for random and plasma glucose were variable. The 75-g oral glucose tolerance test was the most likely confirmatory test to be used if initial screening is positive; however, clinicians relied on different cut-off values and timing. Most (95%) centers routinely assessed fetal growth.
Postpartum screening was undertaken by 90% of centers, using a 75-g oral glucose tolerance test (93%). Most (90%) centers counsel patients about their high risk for further GDM and type 2 diabetes.
Despite the significant variability of antenatal screening and management, postnatal care of GDM was more consistent.
Regional variability trends could not be detected between different regions in the UK. One potential limitation of the survey is the small (2%) proportion of questionnaires completed by obstetricians. However, as proven from the survey, in the U.K. most (85%) centers run joint clinics with both obstetrics and diabetes teams in partnership, with jointly agreed guidelines.
Our report confirms the wide variability in practice across the U.K., in contrast with the U.S., where it has been reported (>10 years ago) that despite the controversies surrounding the optimal management of GDM, program directors of residency and maternal-fetal fellowship programs were in agreement with many aspects of the diagnosis and management (1). The recently reported Australian Carbohydrate Intolerance Study in Pregnant Women confirmed that active treatment of GDM reduces serious perinatal morbidity and may also improve the woman's health-related quality of life (2). Moreover, with the accumulating evidence for rising prevalence of GDM (3), a confirmed long-term impact of hyperglycemia on fetal risks (4), and the potential for prevention studies (including the Diabetes Prevention Program [5] and the Troglitazone in the Prevention of Diabetes Trial [6]), this survey confirms the urgent need for consensus guideline development, especially for antenatal screening and management.
