Blood Glucose Monitoring and Ketone Testing

We realize you may have many questions and concerns about gestational diabetes and we are here to help you in any way we can. The educators at our Center are here to answer your questions and offer suggestions that can make checking your blood sugar and urine easier.

What is gestational diabetes (GDM)?

GDM is a condition where you have high levels of sugar during your pregnancy. This condition is usually seen later in the pregnancy but can also occur earlier. GDM can affect how your baby develops.

How is gestational diabetes treated?

Treatment for GDM is specific for each woman. This includes checking your blood sugar and your urine every day. The results of these tests will help us guide your treatment plan.

How often should I check my blood sugar levels?

You will need to check your blood sugar at least four times a day.

  • Fasting blood sugar: This is the first blood sugar check of the day. You will need to check your blood sugar within ten minutes of waking up in the morning before you eat, drink or exercise.
  • Blood sugar after meals: You will need to check your blood sugar one hour after you start each meal: breakfast, lunch and dinner.

The best results for you and your baby are:

  • Fasting blood sugar: 90 mg/dl or less
  • Blood sugar after meals: 140 mg/dl or less

What are the steps for checking my blood sugar?

These are the steps you should take to check your blood sugar:

1 - Gather your supplies:

  • blood glucose meter
  • lancet
  • strips
  • tissues

2 - Wash your hands with warm water and antibacterial soap. Use warm water to help increase the blood flow to your fingers. Do not use alcohol on your fingers. Alcohol will dry your skin and you may not get correct blood sugar readings.

3 - Let your hands hang below your waist for several seconds. This will help increase the blood flow to your fingers.

4 - Draw an imaginary line down the center of your finger and place the lancet device to the right or left of the line, into the fleshy part of your fingertip. This area hurts less and has more blood supply.

5 - Set up your lancet device. Apply moderate pressure with the lancet and press the button. Put the lancet down and squeeze the tip of your finger with your other hand under the place where you pricked your finger.

6 - Bring the meter to the drop of blood and apply the blood to the strip according to the meter’s directions.

7 - Wait for the meter to give you the reading. Write down the reading. It is important that you write down all of your blood sugar levels.

8 - Remove the lancet and place it in a sharps container or a shatter proof, puncture-resistant plastic container with a screw on top. For example, a washed out bleach or laundry detergent bottle.

How do I throw out the lancet?

1- Before you discard the storage bottle, tape the top securely and label the bottle “Sharps”.

2- Drop off filled sharps container bottles to a drop off center such as:

North Shore University Hospital
300 Community Drive
Manhasset, NY 11030
Outside Emergency Department entrance, near security booth
Monday - Friday (not on holidays)
9:00 am - 4:00 pm

Long Island Jewish Medical Center
270-05 76th Avenue
New Hyde Park, NY 11040
Environmental Services Department (Housekeeping), Ground Floor
Monday – Sunday (not on holidays)
8:00am – 12: 00 am

What are ketones?

Ketones are acid substances in your urine that are created when your body needs to break down fat for nourishment. This occurs when food is not immediately available for you and your baby. This usually happens during pregnancy when a woman is not eating enough. These ketones are called starvation ketones. Starvation ketones can be prevented by not skipping meals or snacks and drinking enough fluids such as water and decaffeinated and unsweetened drinks.

When should I check for ketones?

You should check the ketones in your first morning urine.

How do I check for ketones?

You can check for ketones by following these steps:

  • You can either collect a small sample of urine in a cup and dip the test strip in the urine and remove it quickly, or place your urine ketone stix under your stream of urine.
  • Wait 15 seconds.
  • Compare the color on the ketone stix pad to the color chart on the back of the bottle.
     *If you have large ketones, the color of the ketone stix pad will turn dark purple. This could mean that you either need to drink more water or eat more food. This is not an emergency but you can either call the center to tell one of the educators or discuss this at your next visit.


Helpful Reminders:

  • Check your blood sugar before breakfast and one hour after the start of each meal.
  • Your fasting blood sugar goal should be 90 mg/dl or less. Your blood sugar after meals goal should be 140 mg/dl or less.
  • Check the ketones in your first morning urine.
  • Write down all your test results.
  • Keep in contact with your team. If your blood sugar is out of target range or your ketone stix pad turns dark purple, contact the North Shore Center for Diabetes in Pregnancy Program office at (516) 622-5123.


  • American Diabetes Association. Self-monitoring of blood glucose (consensus statement). Diabetes Care. 1994;18:81-86
  • American Diabetes Association. Standards of medical care for patients with diabetes mellitus Diabetes Care. 2001;24 (suppl 1): S33-S43.