Glucose tolerance test in pregnancy
Pregnant women can develop a
condition known as gestational diabetes (pregnancy-induced diabetes), which can
pose a risk to both mother and baby. A glucose tolerance test is a common type
of test for potential gestational diabetes.
There are several tests to
detect gestational diabetes in pregnant women. The first, called the glucose
screening, is a preliminary screening test done between 26 and 28 weeks. If a
woman tests positive for this screening test, a second test, called a glucose
tolerance test, may be done. This test diagnoses the presence of diabetes by
indicating whether the body is using glucose (a type of sugar) efficiently.
The screening glucose test is
now considered the standard test performed at the beginning of the third
trimester of pregnancy.
What is a glucose
challenge screening test?
No preparation before the test
is required. During the test, the mother is asked to drink a sugary liquid
(glucose) and then blood is taken one hour after drinking, as blood sugar levels
usually peak within an hour. Fasting is not required before this test.
The test assesses how your
body processes sugar. A high blood level may indicate that your body is not
processing sugar efficiently (a positive test). If the results of this screening
are positive, the woman may be tested for glucose tolerance. It is important to
note that not all women who test positive for glucose will have diabetes at a
subsequent diagnosis.
What is a glucose tolerance test?
Before you take a glucose
tolerance test, your doctor will ask you to make sure you eat at least 150 mg
of carbohydrates (about the amount you get from one or two slices of bread)
three days before your appointment. asked quickly. You won't be allowed to eat
or drink anything other than sips of water for 14 hours before the test, so
it's best to schedule the test in the morning.
Also, you should arrange for
someone to drive you to the exam, as your energy levels may be low and there is
a small chance that you will feel dizzy.
When you arrive, a technician
will draw blood to measure your baseline "fasting blood sugar". You
will be asked to drink a larger volume (or more concentrated solution) of the
glucose drink than was used in the original screening glucose test. Your blood
will be drawn and analyzed every hour for the next three hours.
Here are the values
considered abnormal during a glucose tolerance test:
- Abnormal reading interval
- Fasting 95 mg/dl or more
- One hour 180 mg/dL or more
- Two hours 155 mg/dL or more
- Three hours 140 mg/dl or more
What should I do if my glucose tolerance test results are abnormal?
If any of your readings are not normal, your doctor may suggest changing your diet and/or retesting you later in your pregnancy. If two or more of your readings are abnormal, you will be diagnosed with gestational diabetes and your doctor or obstetrician will discuss a treatment plan with you. Treating diabetes during pregnancy is extremely important to protect the health of both mother and baby.