What is gestational diabetes?

Diabetes affects a great number of people in the general population. Combined, approximately 16 million people have type 1 or tpe 2 diabetes. Diabetes can also strike during pregnancy even if a woman has never had problems with her blood glucose levels before. The stress of the pregnancy can cause a woman's body to react differently as compared to when the woman is not pregnant. This can lead to gestational diabetes. It has been estimated that 3 to 5 percent of all pregnant women in the United States are diagnosed as having gestational diabetes. All types of diabetes deals with the fact that the body is unable to utilize the sugar from food appropriately. As a result individuals tend to have increased amounts of glucose in the blood. Under normal conditions glucose is utilized for energy but it can only be used efficiently with the help of insulin. This hormone delivers glucose from the blood to muscles and tissues to be used for energy. Without insulin to transport glucose into body cells to be used as fuel, glucose will accumulate in the body and some may even spill out into the urine through the kidneys. A confusing fact is that women with gestational diabetes have plenty of insulin and can actually have more insulin in their bodies than women who are not pregnant. So why do some pregnant women suffer from high blood glucose levels, or diabetes, if they have plenty of insulin? In women who develop gestational diabetes, the actions of insulin are impaired by an array of hormones produced by the placenta. This results in insulin resistance which usually begins about midway through the pregnancy at about 20 to 24 weeks. The larger the fetus gets, the more hormones are produced that have the potential to block the proper functions of insulin. In most women, the pancreas just produces more insulin to overcome the "canceling" effects of the placental hormones. This is not the case in women with gestational diabetes where the pancreas produces all the insulin it can and still this amount is not enough to regulate blood glucose levels.

Who is at risk for developing gestational diabetes?

Gestational diabetes can affect any woman during pregnancy. Factors which may increase a woman's risk for developing gestational diabetes are obesity; a family history of diabetes; previously giving birth to a large infant; a stillbirth; or a child with a birth defect; or having too much amniotic fluid. Women who are over 25 years of age are at an increased risk for developing gestational diabetes as compared to younger women. Because all women are at risk for gestational diabetes it is necessary that precautions be taken such as screening for the disease through various methods. Such precautions will help to ensure all expecting women the chance of having a healthy pregnancy even if it is discovered that gestational diabetes is present.

How is gestational diabetes detected?

A woman who is at risk for gestational diabetes will be screened for the disease with a glucose challenge. This screening usually takes place between the twenty-fourth and twenty-eighth weeks of pregnancy. The glucose challenge helps the doctor decide whether your body is able to overcome the insulin resistance on its own. The screening consists of having a glucose drink without food.

Gestational diabetes is diagnosed when any two of the following are noted: a fasting plasma glucose of more than 95 mg/dL, a 1 - hour (post glucose challenge) blood sugar level of more than 180 mg/dL, a 2 - hour (post glucose challenge) level of more than 155 mg/dL, or a 3 - hour (post glucose challenge) level of more than 140 mg/dL. Through general screening during pregnancy, gestational diabetes may be identified and can at least lead to appropriate testing.

Gestational diabetes and type 2 diabetes

What is the likelihood of my child or myself developing a long-term form of diabetes?

The risk for the child is low. However, the chances of having a long-term form of diabetes increases with birth size. Obesity is a factor that may contribute to glucose intolerance and diabetes. Therefore, larger babies have a higher chance of getting the disease because they have a higher chance of developing obesity.

The mother is at a high risk of developing diabetes. The risk for getting type 2 diabetes 5-15 years after having gestational diabetes is 40-60% for those who do not have obesity and 75% for those who have obesity, as compared to 15% of women who never had gestational diabetes. Since the risk of type 2 diabetes is so high, it is necessary to be screened for diabetes every year after having gestational diabetes.

How will a physician treat my gestational diabetes?

The physician may ask that lifestyle changes be made to maintain a healthy and safe pregnancy. Lifestyle changes, such as checking blood sugar, limiting the diet to appropriate foods, and exercising will likely be first steps in treating gestational diabetes. Sometimes, daily injections of insulin during pregnancy will be required to manage gestational diabetes. Your physician will determine the combination of treatments that will keep the mother and baby healthy.

Blood Sugar Monitoring

Monitoring blood sugar levels and how they are affected by daily activities is important during pregnancy when the diagnosis of gestational diabetes is made. Today, monitoring your blood sugar is easy and relatively painless. Home blood glucose monitors may be purchased from your local pharmacy. Many different types exist for easy adaptation to your lifestyle. The doctor or pharmacist can help determine the best monitor for a particular individual, and provide instruction on how to use it. The blood glucose monitors today require a small drop of blood to be placed on a strip, which is inserted into the monitor. The monitor will determine the amount of sugar in the blood and display the value on its screen. Normal fasting values for blood sugar are 60-110 mg/dL (3.3 mmol/L - 6.1 mmol/L). The physician will determine what the blood sugar range should be for each individual.

Blood glucose monitoring is usually done at numerous times throughout the day. A common testing schedule is first thing in the morning before eating, which provides a fasting glucose level, and 2 hours after each meal. Because everyone is affected differently by gestational diabetes, the physician will explain how often to test for blood sugar. The date, time, and value of each blood sugar reading should be documented (see the RxLearn glucose monitoring tool). Writing a short note or comment related to a certain blood sugar value and throughout the day can help the individual and their doctor maintain better blood sugar control. A record of blood sugar test results should be provided to the dostor at each visit.

Other Self Testing

Based on certain blood sugar values and for other reasons, the doctor may have an individual check their "ketone body" (here we will use "ketones") levels periodically. Ketones may be found in the blood in increased amounts when blood sugar is not being used for energy. When this happens, the body begins to break down fat, and ketones will be found in the blood and urine. Basically, ketones are a signal that you don't have enough insulin in your body, or that your body is resistant to insulin. Large amounts of ketones can result in a condition called acidosis, which may be harmful to both you and your baby. To learn more about "ketone acidosis", click here. Testing for ketones involves holding a special chemical strip in the urine stream, and comparing the color change to a master color chart to determine the amount of ketones in your urine. Some blood glucose monitors also check for ketones along with the blood sugar. The doctor or pharmacist can provide more information.

Diet

As with normal pregnancies, diet plays an important part in keeping the baby healthy. If a person is diagnosed with gestational diabetes, diet is often the first lifestyle to be changed to help further control the blood sugar. The physician or dietician can provide more information on specific foods that should be included in the diet, as well as recommend multi-vitamins and other nutritional supplements. A dietician can provide information to assure that the mother and baby will be eating healthy.

Some general rules to follow when developing a diet are:

• Avoiding foods high in sugar - Most people think only of candy and sweets as high sugar foods. However, there are other foods that many of us consider "healthy" which contain a high sugar content. These include: soft drinks, fruit drinks, canned fruits packed in syrup, and even some fruit-containing yogurts. Because fruit juices have a high sugar content, they should be consumed in limited amounts.
• Eating foods containing complex carbohydrates and fiber - A diet including high fiber foods helps to maintain normal blood sugar levels. Some foods to include are: beans, vegetables, cereal, whole grain breads, fruits, rice, pasta, and potatoes.
• Eating foods that are low in fat - Foods that have a high saturated fat and total fat content should be avoided. Because both the mother's body and the baby need some fat in the diet to stay healthy, unsaturated fats can be used. Olive oil or canola oil when cooking are better choices than butter. Finally, make use of food labels to identify the type and amount of fat in the product.
• Eating a bedtime snack - Make sure this snack is high in protein and complex carbohydrates. This will help to maintain blood sugar levels throughout the night. Again, the doctor or dietician can provide information about an appropriate diet.

Exercise

Along with the proper diet, exercise plays an important role in keeping the blood sugar in the range that is appropriate during pregnancy. The physician will provide information and advice on exercises that will help to maintain a healthy pregnancy. Often, a person can continue an exercise programs they are participating in before pregnancy, but it is very important to make sure the doctor is aware of the type of exercise program. Some good choices of exercises during pregnancy include swimming or water aerobics, walking, and stationary bicycling. Individuals should exercise most days of the week, always including a warm up and cool down period. The pulse rate should be monitored during exercise, with the aim to keep it less than 140 beats per minute. Because exercising can affect blood sugar and even cause it to become too low, any activity should be stopped immediately if there are signs or symptoms of low blood sugar, such as lightheadedness, dizzyness, or feeling shaky. A source of sugar should be available to treat low blood sugar. The doctor should be notified if blood sugar goes too low. Finally, plenty of drinking water should be available before, during, and after your workout.

Insulin Therapy

Insulin therapy may be needed when it is determine that diet and exercise alone are not controlling the blood sugar during gestational diabetes. The physician will use the home blood glucose values to determine if adequate sugar control is being achieved, so monitoring the blood sugar is crucial. Doses of insulin differ for each person. It is typical that more insulin is required as pregnancy progresses. This does not mean that the condition is getting worse. Insulin must be administered with an injection and the needles available today are very small and relatively painless. The doctor and pharmacist will be able to demonstrate the proper filling of the syringes and self-injection techniques. Because activities may change from day to day, the signs of both high and low blood sugar must be understood. When the blood sugar is elevated, there may be an increase in appetite and thirst, and the individual may have to urinate more frequently. If the blood sugar is too low, the individual may have a more rapid heartbeat, become sweaty, develop blurred vision, and feel faint. This may be a sign that the insulin dose was too high. The doctor needs to be notified if there are symptoms of high or low blood sugar.

Vera M. Krainik
Email: v-krainik@onu.edu

Vera Krainik is a pharmacy student at Ohio Northern University's Raabe College of Pharmacy, and is actively involved in independent studies of chronic diseases and related complications.

Stacy M. Ramga
Email: c-dunbar@onu.edu

Stacy Ramga is a pharmacy student at Ohio Northern University's Raabe College of Pharmacy, and is actively involved in independent studies of chronic diseases and related complications.

Jessica Marie Roberts
Email: j-roberts@onu.edu

Jessica Roberts is a pharmacy student at Ohio Northern University's Raabe College of Pharmacy, and is actively involved in independent studies of diabetes and related complications.