Women's Healthcare Topics

How to Test Your Blood Sugar Levels in Pregnancy

Reviewed by James Brann, M.D.

Test Frequently

In order to build a healthy plan for controlling gestational diabetes, the goal must be to keep your blood sugar levels in the normal range throughout the day. This must be priority #1.

When we eat foods that are healthy and normal for our body, sugar is released slowly and converted into blood glucose in a manner that maintains normal blood sugar levels. Eating unhealthy foods such as highly processed foods that are full of sugar, creates a rapid release of glucose and results in a higher than normal blood sugar level.

The first step in a healthy plan for controlling gestational diabetes is knowing what your blood sugar level is by testing at intervals throughout the day.

Women with gestational diabetes should measure their blood glucose levels at least four times a day. You should include a fasting blood sugar and a blood sugar one or two hours after each meal. Your results should be recorded in a glucose log, along with dietary information about what foods you ate. The glucose log will help your physician decided if you should begin an ant-hyperglycemic medication along with your diabetic diet. Conversely, your physician may decrease the frequency of glucose monitoring if you are in good control with diet alone.

Keeping blood glucose levels in a healthy range at all times requires eating a healthy meal every 3-4 hours, getting regular exercise and if necessary taking insulin or other glucose lowering (hypoglycemic) medications. Achieving a normal maternal blood glucose level decreases the chance of having pregnancy related complications such as preeclampsia, preterm labor, and delivery of a large baby.

Recommended Glucose Monitoring Levels

Learn about how and when to test your blood sugar levels.

The American College of Obstetricians and Gynecologists (ACOG) and the American Diabetes Association (ADA) both have similar recommendations for your target blood glucose levels in pregnancy. If the suggested blood glucose levels are met, this would mean that you have excellent control of your gestational diabetes and can avoid the complications associated with gestational diabetes.

The recommended glucose values are:

  • Fasting blood glucose of less than 95 mg/dl

  • A blood glucose of less than 100 mg/dl before each meal

  • One hour after eating your glucose level should be less than 140 mg/dl

  • Two hours after eating your glucose level should be less than 120 mg/dl

How Do You Test Your Blood Sugar Level?

Testing glucose levels is quick and simple. Most drug stores, medical supply stores and pharmacies carry testing supplies and many are covered under health insurance. Renting a glucose meter might be an option, as it may only be needed during pregnancy. Here are the basic steps in a nutshell:

  • Wash hands thoroughly with soap and water

  • Prick your finger with a lancet and squeeze a drop of blood.

  • Place the drop of blood on the paper strip that fits into the glucose meter

  • Wait a few seconds and the meter will give you a number for your blood sugar level, like 115 mg/dl

When to Test?

According to the American Diabetes Association (ADA) self-monitoring blood glucose or SMBG in pregnant women with a prior history of diabetes should test as follows:

  • Before each meal

  • One or two hour after each meal

  • At bed time

  • Occasional between 2 and 4 AM. (test when you have symptoms of low blood sugar at night)

Home glucose monitoring test kits

There are many different glucose monitoring test kits on the market. Some are more accurate than others. You should check the accuracy of your meter by bringing it with you to your prenatal visits and use your home meter to check your blood sugar level at the same time that your physician draws your blood sample. There should not be a larger than 15% difference in the two glucose results. If there is a large difference the problem may be with your meter, blood strips or your technique for drawing the sample. Most home glucose meters are accurate, however use common sense if your readings do not fit with your symptoms. Example low blood sugar (a value less than 63 mg/dl) without symptoms of irritability, confusion and feeling faint could mean an inaccurate reading.

Causes of early morning high blood glucose

There are two main reasons that when you test your blood sugar in the morning that it is higher than your bedtime glucose level. The dawn phenomenon is an elevated blood glucose level that is seen around 3 to 5 am. It is due to the normal overnight secretion of hormones that inhibit insulin function resulting in high blood glucose levels in the morning. The second phenomenon is the Somogyi Effect and it refers to the rebound high blood glucose level 6 to 12 hours after a low blood sugar level before going to bed.

High morning blood glucose levels may also be due to a high carbohydrate snack before bedtime. Do not worry with this booklet you will learn which snacks to avoid before bedtime and what specific foods you should have eating.


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