Universal Diabetes Screening Recommended During Pregnancy

New US federal recommendations suggest that all women should be screened for gestational diabetes at 24 weeks of pregnancy, even if they have no symptoms.

The B-level recommendation from the US Preventive Services Task Force (USPSTF; Rockville, MD, USA) aligns with that of several other organizations, including the American Association of Clinical Endocrinologists, the American Diabetes Association (ADA, Alexandria, VA, USA), and the American College of Obstetricians and Gynecologists (ACOG).

The USPSTF recommends testing with a 2-hour, 50 gram oral glucose challenge test (OGCT) between 24–28 weeks of gestation. If patients hit or exceed a threshold of 130 mg/dL, they should follow-up with the 2-hour, 100 gram oral glucose tolerance test (OGTT). Other options for screening include a fasting plasma glucose or screening based on other risk factors, but the task force claims there is limited evidence on these alternative screening approaches. The task force concluded that there is insufficient evidence to assess risk and benefits of screening before 24 weeks' gestation.

The Task Force stated that screening and treatment lower the risk of preeclampsia, a condition in pregnant women characterized by high blood pressure and high levels of protein in the urine, which can result in life-threatening seizures. Treating diabetes during pregnancy can also prevent babies from growing larger than normal (macrosomia), a condition that can lead to birth injuries. The USPSTF recommendations were published on January 14, 2014, in the Annals of Internal Medicine.

“Diabetes that begins during pregnancy can cause serious health problems for expectant mothers and their babies,” said USPSTF chair Virginia Moyer, MD, MPH. “The good news is that screening all women after 24 weeks of pregnancy is simple, and can result in better health outcomes for both the mother and the baby.”

“All women should talk to their doctors or nurses about actions they can take before becoming pregnant to improve their health,” added Dr. Moyer, “including maintaining a healthy weight, quitting smoking, and managing any chronic conditions.”

In the OGTT, a standard dose of glucose is ingested orally and blood levels are checked two hours later. Fasting plasma glucose (measured before the OGTT begins) should be below 110 mg/dL. Fasting levels of 110–125 mg/dL are indicative of impaired fasting glycemia, while fasting levels repeatedly at or above 126 mg/dL are diagnostic of diabetes. A 2-hour OGTT glucose level below 140 mg/dL is normal, whereas higher glucose levels indicate hyperglycemia. Blood plasma glucose of 140–200 mg/dL indicate impaired glucose tolerance, and levels above 200 mg/dL at 2 hours confirms a diagnosis of diabetes.

Related Links:
US Preventive Services Task Force
American Diabetes Association