All pregnant women should be screened for gestational diabetes after 24 weeks of gestation, according to a final recommendation statement from the U.S. Preventive Services Task Force.
The updated statement, published online Jan. 13 in Annals of Internal Medicine, represents "a change in thinking about how the collective benefits of preventing complications during pregnancy and birth – such as birth injuries, preeclampsia, and babies growing too large in the womb – are important according to Dr. Virginia A. Moyer, task force chair.
Dr. Virginia A. Moyer
"The USPSTF determined that screening for and treatment of GDM [gestational diabetes] in women after 24 weeks of gestation are associated with moderate health improvements in the mother and infant through the collective reduction in preeclampsia, macrosomia, and shoulder dystocia. The harms of screening or treatment are considered no greater than small. Therefore, the USPSTF concludes with moderate certainty that the overall net benefit is moderate," Dr. Moyer wrote on behalf of the task force.
The recommendation to screen after 24 weeks is a "B recommendation," based on a systematic review of the literature.
The final recommendation updates the task force’s 2008 recommendation. At that time, USPSTF found insufficient evidence to recommend screening of asymptomatic women, and issued an "I recommendation."
GDM prevalence in the United States is between 1% and 25%, depending on patient demographics and diagnostic thresholds, according to the statement.
Women with GDM are at increased risk for developing type 2 diabetes mellitus, with 15%-60% developing type 2 diabetes within 5-15 years of delivery, Dr. Moyer said in an interview.
"Screening women after 24 weeks of pregnancy helps to identify the disease in women earlier so that they can work with their doctors to identify whether treatment is needed," she added, noting that evidence demonstrates that treatment for gestational diabetes reduces complications.
Evidence reviewed by USPSTF indicates that primary care providers can accurately detect GDM after 24 weeks’ gestation using the two-step 50-g oral glucose challenge test, followed by the oral glucose tolerance test if the screening threshold is met or exceeded (130 mg/dL, 135 mg/dL, or 140 mg/dL [7.21, 7.49, or 7.77 mmol/L]).
In 2013, the American Congress of Obstetricians and Gynecologists recommended use of the two-step approach using the 50-g oral glucose challenge test. Although the American Diabetes Association endorsed the one-step 75-g, 2-hour oral glucose tolerance test, an independent panel supported by the National Institute of Health Consensus Development Program released a draft statement that evidence is insufficient for adopting the one-step approach.
Recommendations of the American Academy of Family Physicians and the Endocrine Society are in line with the updated USPSTF recommendation.
"Clinicians now have good evidence to support continuing to screen pregnant women for diabetes after 24 weeks of pregnancy," Dr. Moyer said.
Although high-risk women can be screened earlier than 24 weeks, the evidence regarding earlier screening remains insufficient for assessing the balance of benefits and risks asymptomatic women, thus the task force issued an "I statement."
Dr. Moyer reported no relevant conflicts of interest.