by EBSCO Medical Review Board

Gestational diabetes mellitus (GDM) needs to be monitored. This can be done with glucose monitoring and ketone testing.

Glucose Monitoring

Things like eating and exercising cause changes in glucose levels. Also, the hormones released by the placenta cause levels to rise throughout pregnancy. Glucose levels are monitored using a glucose monitoring kit.

A drop of blood is needed for testing. To get the drop of blood, a woman may use:

  • A lancet—a disposable, sharp needle-like pricking device
  • A lancet device—a spring-loaded tool used for a finger prick

The drop of blood is put on a test strip. A woman may need to compare the strip to a color chart to find out the level. A glucose meter is more common. It is a device that reads the test strip and shows a digital result.

A woman will be told when and how often to test. Often times, this will be after a meal. The results will need to be saved or written down and shared with the healthcare provider. It will help guide treatment.

Ketone Testing

A woman's urine may need to be tested for ketones. These are made when the body breaks down fat instead of carbohydrates for energy. Large amounts of ketones can lead to a problem called ketoacidosis. It can harm the woman and the growing baby.

A ketone kit has individual-use strips. A woman passes the strip through the stream of urine or places it in a cup of urine. The strip is compared against a color chart to find out if ketones are in the urine.

The test is done in the morning before breakfast and when glucose test results are high. The results will need to be written down and shared with the healthcare provider. It will help guide treatment.


American College of Obstetricians and Gynecologists Committee on Practice Bulletins—Obstetrics. Practice Bulletin No. 190: Gestational Diabetes Mellitus. Obstet Gynecol. 2018 Feb;131(2):e49-e64.

Gestational diabetes. American Diabetes Association website. Available at: Accessed January 14, 2020.

Gestational diabetes mellitus (GDM). EBSCO DynaMed website. Available at: . Updated December 18, 2019. Accessed January 14, 2020.

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