Hypoglycemia or low blood sugar during pregnancy is a common problem in women with diabetes. This blood sugar complication can occur in pregnant women who have preexisting type 1 or type 2 diabetes or in women who have gestational diabetes -- which is usually diagnosed during the second trimester of pregnancy. Linked to the use of insulin or certain diabetes pills, hypoglycemia can cause symptoms such as shakiness, confusion and dizziness. Hypoglycemia rarely occurs in pregnant women without diabetes. Prevention and treatment are important as low blood sugar levels can have negative consequences for both the mom and baby.
Signs and Symptoms
Hypoglycemia is traditionally defined as having a blood sugar below 70 mg/dl. However, because blood sugar levels run lower during pregnancy, the consensus of a work group of the American Diabetes Association and the Endocrine Society, in a report published in the May 2013 issue of "Diabetes Care," is that hypoglycemia in pregnancy can be defined as a level below 60 mg/dl.
Low blood sugars have a sudden onset and can vary in intensity. Symptoms of mild hypoglycemia can resemble early pregnancy symptoms, including hunger, nausea, sleepiness, headache, weakness and dizziness. Other symptoms a woman may experience include shakiness, nervousness, sweating, chills, nightmares, fast heartbeat, blurry vision and numbness around the mouth. When blood sugars drop so low the woman is unable to treat it without assistance, this is termed severe hypoglycemia with symptoms of confusion, lack of coordination, seizures, loss of consciousness and even death. Some women with long-standing diabetes may no longer feel the early symptoms of low blood sugar levels and, as a result, are at greater risk of suffering these more serious side effects.
Women at Risk
Pregnant women at highest risk for hypoglycemia are those taking insulin or a type of diabetes pill such as glyburide -- a medication that increases the body's production of insulin. Insulin is required to move excess sugar from the blood into the body cells so that it can be used or stored as energy. As high blood sugar levels can be harmful to both the mom and fetus, these medications are essential for many women to achieve blood sugar control. However, hypoglycemia is linked to these medication therapies. For example, a study published in the October 2007 issue of "Diabetes Care" found that 45 percent of pregnant women with type 1 diabetes suffered from at least one severe hypoglycemia episode during their pregnancy, with 80 percent of these occurring prior to the 20-week mark. The increased risk of hypoglycemia during the first trimester is due to the improved action of insulin in the body.
Causes and Prevention
Low blood sugar is directly related to having too much of the hormone insulin in the blood along with not enough food to balance insulin's blood-sugar-lowering effect. Because it improves the action of insulin, physical activity can also cause low blood sugar levels. Eating a balanced diet and small, frequent meals throughout the day can help to prevent blood sugar drops. Also important to keep blood sugars stable is learning how to balance the amount of carbohydrate foods consumed with the medications and learning how to add food or decrease medications when active. In addition, exercising after a meal or snack can be an effective strategy to prevent hypoglycemia. Testing blood sugar often and carrying supplies for prompt treatment are also critical steps for preventing and treating low blood sugar.
Hypoglycemia needs to be treated promptly, so a woman at risk needs to be prepared. The American Diabetes Association recommends treatment with 15 grams of carbohydrate from an easily digested food item -- such as 4 ounces of fruit juice, 1 cup of nonfat milk, 1 tablespoon of sugar or 3 to 4 glucose tablets. After 15 minutes, the blood sugar often returns to normal, but if it's still low, another 15 grams of carbohydrate needs to be consumed. Most episodes of low blood sugar can be self-treated. However, in the case of severe hypoglycemia -- when a woman is unable to eat or drink something -- emergency medical attention is required. Alternatively, a woman's physician may prescribe a glucagon kit for home use, as the injection of this hormone can effectively raise the blood sugar level by stimulating the liver to produce and send sugar into the bloodstream.
Women experiencing hypoglycemic episodes during pregnancy are at an increased risk of losing consciousness. Severe hypoglycemia can cause accidents, injuries, coma or even death to the mother and, as a result, can also harm the baby. Frequent blood sugar monitoring is important to identify hypoglycemia and determine trends and patterns that indicate when a therapy adjustment is needed. Ongoing education and medical followup are important to safely achieve blood sugar control during pregnancy. The attention to blood sugars needs to continue after delivery, as insulin requirements drop immediately after birth and while breastfeeding, making hypoglycemia more likely during these times.
The National Institute of Diabetes and Digestive and Kidney Diseases warns that hypoglycemia may also be a sign of more severe conditions such as liver, heart or kidney disorders; a hormone deficiency; or a pancreatic tumor. Medical care is needed for anyone having frequent or severe hypoglycemia.
- American Diabetes Association: Hypoglycemia (Low Blood Glucose)
- Journal of Diabetes and Metabolic Disorders: The Importance of Hypoglycemia in Diabetic Patients
- Canadian Diabetes Association: Diabetes and Pregnancy
- National Institute of Diabetes and Digestive and Kidney Diseases: Hypoglycemia
- Diabetes Care: Hypoglycemia and Diabetes: A Report of a Workgroup of the American Diabetes Association and the Endocrine Society
- Diabetes Care: Hypoglycemia in Pregnant Women With Type 1 Diabetes: Predictors and Role of Metabolic Control