Insulin is a hormone that moves glucose, or blood sugar, from the blood into the body’s cells, where it’s then stored or used for energy. During pregnancy, your body produces more insulin to help your baby grow. At the same time, pregnancy can also make you more resistant to insulin. This is why many women develop diabetes during pregnancy (gestational diabetes).

Though high blood sugar (hyperglycemia) is more common in pregnancy, the changes in your body during pregnancy and how you react to insulin can also make your blood sugar drop dangerously low. That causes a condition called hypoglycemia. A blood sugar reading of less than 60 milligrams per deciliter (mg/dL) is considered hypoglycemia. Hypoglycemia during pregnancy happens most often in women with diabetes.


Persistent hypoglycemia in pregnant women without diabetes is rare. Sugar levels can dip too low during pregnancy when any of the following occur:

  • You don’t eat frequently enough or the right kinds of foods to stabilize blood sugar levels. Regardless of how much or how often you eat, your baby will continue siphoning glucose from your body. Your body is usually good at compensating for this.
  • You exercise excessively, using up glucose. If there isn’t enough glucose in your body or you don’t replenish it with some carbs, you may become hypoglycemic.
  • Your diabetes medication doses are too effective at lowering blood sugar and need to be modified. This is the most common reason for hypoglycemia during pregnancy.

Hypoglycemia and diabetes

Hypoglycemia can occur in pregnant women without diabetes, but it’s much more likely to be seen in women taking insulin. Each of the following types of diabetes puts you at a higher risk for hypoglycemia episodes:


The symptoms of hypoglycemia are generally the same in pregnant women and in people who are not pregnant. They include:

  • nausea or vomiting
  • lightheadedness
  • shaking
  • heart palpitations
  • sweating
  • anxiety
  • tingling around the mouth
  • pale skin

Once blood sugar is raised, these symptoms disappear.


Hypoglycemia during pregnancy is fairly common. Women with diabetes are much more likely than women without diabetes to experience hypoglycemia. In one study, 23 percent of women with type 1 diabetes had a severe hypoglycemic attack at least once during pregnancy, and many had several. A severe hypoglycemic attack is when blood sugar dips so dangerously low that you risk losing consciousness.

In an older study, some 19 to 44 percent of pregnant women with diabetes of all kinds experienced hypoglycemia.

Risk factors

Hypoglycemia can occur at any time during your pregnancy. Certain things will increase the risk, though. These include:

  • Having diabetes. Both pregnancy and diabetes cause your insulin levels to fluctuate. To avoid having either too much or too little sugar, you will have to be carefully monitored and may need to have your diabetes medications adjusted.
  • Being in your first trimester. Hypoglycemia more often occurs during the first trimester when many moms may be experiencing nausea and vomiting. In one study, pregnant women with type 1 diabetes experienced severe hypoglycemia three times more frequently in the first trimester than the period before pregnancy. The most likely time for a severe hypoglycemic attack is between 8 and 16 weeks of pregnancy. The least likely time is in the second trimester.
  • Having had hypoglycemic attacks before pregnancy.
  • Being sick. Many illnesses cause a lack of appetite, and without adequate or regular food intake, you might develop hypoglycemic episodes.
  • Being malnourished. It’s important to take in enough calories during pregnancy. The foods you eat should also be nutritious.


Your doctor will make the diagnosis of hypoglycemia based on your symptoms and blood glucose readings. You may be asked to take several readings a day and record them. Your doctor can prescribe a blood sugar monitoring kit, or you can buy one over the counter in a drugstore. A single low blood sugar reading doesn’t mean you have ongoing hypoglycemia.

Treatment and prevention

If you start to feel any of the symptoms of hypoglycemia:

  • Find a safe place to sit or lie. If you’re driving, pull over.
  • Eat or drink about 15 grams of carbohydrates. Simple carbs generally have a high sugar content. Examples are 4 ounces of fruit juice (not diet or reduced sugar), half a can of regular soda, 4 glucose tablets, and one tablespoon of sugar or honey. Always keep supplies like these with you.
  • Make your doctor aware of any hypoglycemic episodes you have.

If you have diabetes, your doctor will have to adjust your medications to stabilize your blood sugar levels. Rarely, you may be given a prescription for what’s called a glucagon kit. This kit will contain a synthetic form of the hormone glucagon and a sterile syringe. When injected, the glucagon will stimulate the liver to release stores of glucose. That, in turn, raises blood sugar levels. It’s used as a rescue treatment for severe hypoglycemia.

The key, though, is reducing your risk of hypoglycemia in the first place.

  • Eat small, frequent, well-balanced meals to keep blood sugar levels steady.
  • You fast while you’re asleep, so make sure you keep a snack by your bed so you can eat if you wake during the night or first thing in the morning.
  • Exercise, unless your doctor has advised against it, but do not exceed your normal level. The effects of excessive exercise on your blood sugar can last for up to 24 hours.


An occasional hypoglycemic episode during pregnancy likely won’t cause any harm to you or your baby. When it’s frequent, there can be problems. The brain needs glucose to receive messages from the body and interpret them.

In severe cases in women with diabetes, hypoglycemia can lead to seizures, coma, and even death. Your baby may experience the same complications if they’re born with hypoglycemia or develop it soon after birth.


Hypoglycemia is uncommon during pregnancy if you don’t have diabetes. Infrequent or mild hypoglycemia usually doesn’t pose significant harm to a mom or her baby. There’s no fool-proof way to prevent hypoglycemia, but you can reduce your risk. Eat regularly, and, if you have diabetes, closely monitor your blood sugar levels. Recognize the signs of hypoglycemia and keep your doctor informed of any attacks you may have.