Keeping your blood sugar level well controlled is one of the most important things that you can do for your baby's health. For women with pre-existing diabetes, this may require that you take insulin instead of anti-diabetic pills or that you increase your dosage of insulin by up to three times your usual amount for the duration of pregnancy. For women with gestational diabetes (GDM), this may mean having to take insulin for the first time. Typically, women who require insulin therapy for gestational diabetes will not require insulin therapy after delivery.

Anyone who is taking insulin is at a risk for a hypoglycemic reaction
(low blood sugar). Low blood sugar is when your glucose level is 70mg/dl or less.

The following can cause low blood sugar:

  • taking an excessive amount of insulin
  • skipping scheduled meals and snacks
  • excessive unplanned exercise 


During pregnancy, the number of times that you check your blood sugar can increase to 6-10 times a day. The target blood sugar goals are 70- 90 mg/dl, fasting (before you eat or drink anything), 140mg/dl or less, one hour after meals, and 70-110mg/dl between 2-4 am. The best tool to help you to recognize low blood sugar is blood glucose monitoring .

Signs and symptoms of low blood sugar include:

  • sweating
  • shaking/trembling
  • tingling feeling in your mouth or tongue
  • confusion
  • slurred speech
  • hunger
  • headache
  • irritable mood
  • troubled sleep or nightmares
  • unexplained weakness 


If you think your blood sugar is low (70mg/dl or less) it is important to check your blood sugar first (if possible) before you treat it. Some of the hormones produced by the placenta can make you feel like your blood sugar is low even when this is not the case. Treating symptoms that are not caused by low blood sugar can result in high blood sugar instead.

The preferred treatment for low blood sugar is glucose tablets. Glucose tablets can be bought over the counter in any pharmacy. The reason we recommend using glucose tablets is because they have a predictable response. One gram of glucose should raise blood sugar approximately 3 points. Each tablet contains 4-5 grams of glucose, therefore each tablet should raise blood sugar level approximately 12-15 points.

Having low blood sugar can feel very scary. It is not uncommon to over-treat that feeling by eating until the symptoms stop, thereby raising blood sugar levels too high. It is important to learn to stay calm and in control of your behavior during periods of low blood sugar. It also is important to have a plan of action in place before you have a low blood sugar in order to prevent over-treating and help reduce the fear that one can feel.

Treating Hypoglycemia

1. Check your blood sugar. If it is 70mg/dl or less, go on to step two.
2. If you are due for a meal or snack, have one. If not , treat with 15 grams of carbohydrates ( 3-4 glucose tablets).
3. Stop eating and give your blood sugar levels about 15-20 minutes to rise.
4. After 15-20 minutes, recheck your blood sugar.
5. If your blood glucose level is 50mg/dl or less repeat steps two, three and four.

If your blood sugar is 30mg/dl or less use 30 grams of carbohydrates to treat your low blood sugar level.

Always carry fast-acting glucose with you. Avoid using a food that is very high in fat to treat low blood sugar because this could slow down the rise in your glucose level.

Other forms of fast-acting glucose:

  • LifeSavers (8-10 pieces)
  • Regular soda (non-diet) (4-6 oz)
  • Low/no-fat milk (8 oz)
  • Apple/orange juice (4 oz) 

Preventing Hypoglycemia 

After your blood sugar is within target range it is important to examine why you became hypoglycemic. Ask yourself the following questions:

1. Did I not eat enough or skip a meal or snack?
2. Did I give myself too much insulin to cover a meal or snack?
3. Was I very physically active today, i.e. cleaning, walking, doing laundry?
4. Am I having a low blood sugar reaction at the same time frequently?

If you are experiencing frequent low blood sugars (3 times a week or more) call the Center for Diabetes in Pregnancy to discuss a treatment plan.

It is important for women who are on multiple injections or the insulin pump to have unexpired glucagon in the house and to wear a medical alert bracelet.