Who: All pregnant women.

Why: To check for gestational diabetes (diabetes during pregnancy).

When: Between 24 and 28 weeks of pregnancy.

How: The health care provider takes a blood sample 1 hour after the woman consumes a drink containing glucose (a form of sugar).

If the screening test shows high blood sugar levels, the woman will need to take a diagnostic test to find out if she has gestational diabetes. The diagnostic test takes 3 hours.

Risks: Possible bruising or soreness at the needle site.

For more information, read the fact sheet Diabetes in Pregnancy.

November 2008