A healthy pregnancy with diabetes is a challenge, but consider this: Less than 100 years ago, before the discovery of insulin, many young women with Type 1 diabetes didn’t even live to reach childbearing age. And less than 30 years ago, physicians routinely told young women with Type 1 diabetes that pregnancy was far too dangerous for both mother and child. Today, thanks to advances in diabetes treatment, plus improvements in medical care for infants, there has never been a better time for you to have a healthy baby. Insulin pump therapy is one of the options available to women today for managing diabetes during pregnancy.
Challenges of pregnancy
Pregnancy with diabetes presents a variety of challenges for you and your diabetes management team far beyond the routine morning sickness, fatigue, and strange food cravings experienced by many women who are expecting. The length of time you’ve had diabetes as well as the course of your disease influences the seriousness of medical risks during your pregnancy. For example, if you have mild retinopathy, it may progress during pregnancy. Your kidney status could worsen. Women with diabetes are at higher risk for frequent and severe hypoglycemia (low blood glucose) during pregnancy because glucose crosses the placenta to provide nutrition for the growing baby. The pregnancy state also tends to allow diabetic ketoacidosis—a dangerous condition usually accompanied by very high blood glucose—to develop quickly. Having a thorough medical evaluation prior to pregnancy is extremely important for determining your individual situation and management solutions. Good blood glucose control before and during pregnancy will minimize all risks to the mother.
Risks to the baby are also a consideration when a woman has diabetes. Most birth defects in infants born to mothers with diabetes are directly related to the mother’s degree of high blood glucose at the time of conception. Infants of mothers with poorly controlled diabetes have an increased rate of congenital malformations of the heart, skeleton, and nervous system. Spontaneous abortion, or miscarriage, is also known to occur more often in women with high blood glucose. Additional potential problems include macrosomia, which means the baby is larger than normal for its developmental age, low blood glucose in the baby at birth, and respiratory distress syndrome.
Because the fetal organs are largely developed within the first eight weeks of pregnancy, which may be before you even realize you are pregnant, optimal blood glucose control before conception should be your primary goal. The good news is that if you can maintain normal blood glucose levels before conception and during your pregnancy, you can reduce the risks to yourself and your baby to those of women who don’t have diabetes.
When you have diabetes, it’s critically important to plan for pregnancy before conception. For women with no immediate desire to start or expand their family, that includes finding a reliable method of birth control to prevent an unplanned pregnancy.
If you would like to become pregnant within the next year, you should meet with your obstetrician to determine your overall health, stamina, and ability to conceive and carry a pregnancy to term. Genetic counseling may also be beneficial. A diabetes educator can provide intensive education to help you understand the effects of pregnancy on diabetes, as well as work toward optimal blood glucose control for diabetes and pregnancy. Ideally, you should strive for near-normal blood glucose levels for at least three months prior to pregnancy. During this time, be sure to use a reliable method of birth control, and use this time to make sure you have the personal commitment, along with family support, to sustain you through frequent medical and obstetrical visits during the nine months of pregnancy.
Blood glucose control during pregnancy
Regardless of the type of diabetes you have, a goal of optimal blood glucose control is essential for a healthy pregnancy. The blood glucose control goals suggested by the American Diabetes Association are lower for pregnant women than for the general population with diabetes. (See “Blood Glucose Goals for Pregnancy” for specifics.) Since your blood glucose goals also depend on the type of meter you use for self-monitoring, be sure you know whether your meter gives whole blood or plasma glucose values. Most health-care professionals prefer the use of a meter that gives plasma-correlated glucose values during pregnancy, if possible.
The following are some strategies for maintaining optimal blood glucose control before and during pregnancy:
Management by a diabetes team. Working with a health-care team that specializes in pregnancy and diabetes is vital to your well-being. Diabetes management team members include a physician to manage your diabetes (such as an endocrinologist); your obstetrician; certified diabetes educators, including a registered nurse and registered dietitian; as well as a pediatrician/neonatologist and perhaps a social worker. Support specialists such as an ophthalmologist and perinatologist may also be members of your health-care team. A reliable health-care team can provide care and support through the process of planning a pregnancy so that when pregnancy occurs, you have help managing both your diabetes and your pregnancy.
Nutrition. If you are planning a pregnancy, meeting with a registered dietitian who specializes in diabetes is recommended. Nutrition assessment generally focuses on calorie and carbohydrate needs for ideal body weight and optimal blood glucose control. A folate supplement to reduce the risk of neural tube defects is recommended for all women of childbearing age.
Physical activity. A good exercise plan that enhances physical fitness assists you with meeting goals for optimal blood glucose control. Physical activity can also be helpful in relieving stress.
Blood glucose self-monitoring. The American Diabetes Association suggests frequent blood glucose monitoring during pregnancy, on a schedule of once before each meal, one hour after each meal, at bedtime, and once in the middle of the night, for a total of at least eight checks per day. Your diabetes management team may individualize your monitoring schedule to meet your specific needs.
Medication. The medicine most commonly used for blood glucose control during pregnancy is insulin. Women with Type 1 diabetes always require insulin as part of their treatment plan. Women with Type 2 diabetes who take oral medicines as part of their diabetes treatment plan will usually find that insulin, rather than pills, is recommended during pregnancy. With a physician’s guidance, a woman with Type 2 diabetes contemplating pregnancy may switch to insulin therapy prior to becoming pregnant. Using insulin may allow a woman to control her blood glucose levels as tightly as possible both prior to and during the early weeks of pregnancy.
The types of insulin used during pregnancy and the method of delivering the insulin should be decided on by a physician with the expertise to manage diabetes. Insulin can be delivered with a syringe, an insulin pen device, or an insulin pump. This article focuses on the use of insulin pump therapy in pregnancy.
Insulin pump therapy
Insulin pump therapy has become an increasingly popular option for diabetes management in the past couple of decades. In fact, the number of insulin pump users grew from 6,600 users in 1990 to 100,000 in 2000. The growing numbers of pump users include women with diabetes who choose to use pump therapy as a means to obtain and maintain the tight blood glucose control necessary for a healthy pregnancy.
An insulin pump is a computerized mechanical device about the size of a pager. It pumps rapid- or short-acting insulin through a length of tubing to a small catheter or needle that is inserted into the fat layer under the skin. Insulin is pumped continually at a preprogrammed basal rate, and the pump wearer programs in a bolus amount of insulin at meals and snacks based on the amount of carbohydrate in the food to be eaten. While pump therapy has been used safely and successfully in pregnant women with Type 2 and gestational diabetes, it is most commonly part of a pregnancy treatment plan for women with Type 1 diabetes.
Benefits. One advantage to using an insulin pump during pregnancy is the ability to make very small insulin dose adjustments; for example, some pumps allow adjustments in 1/10-unit increments. In addition, the basal rate of insulin infusion can be changed hourly (or even every half hour, if necessary), allowing the user to closely match insulin delivery with insulin need. These features may be particularly useful as pregnancy progresses, hormone levels change, and insulin needs change accordingly.
Risks. One of the risks of pump use is that if the infusion of insulin is disrupted for any reason, high blood glucose can occur quickly since only rapid- or short-acting insulins are used in pumps. High blood glucose is always a concern for people with diabetes, but it is especially so during pregnancy when the health of the baby is also at stake.
Low blood glucose, or hypoglycemia, is a risk with any type of insulin therapy, including pump therapy. However, it may be less of a risk with pump therapy. A study published in the journal Diabetes Care in 1996 involving 55 people with Type 1 diabetes showed that the incidence of severe hypoglycemia declined more than sixfold during the first year of insulin pump therapy as compared to previous management on multiple daily insulin injections.
Weight gain is another possible risk of insulin pump therapy. It is usually the result of at least one of the following:
- Improvement in blood glucose control. When blood glucose is high, calories are eliminated in the urine. When blood glucose is brought into the normal range, those calories are instead absorbed by the body.
- Delivery of too much insulin, leading to hypoglycemia, leading in turn to consuming carbohydrate to raise blood glucose.
- Managing high-calorie foods or large portions of food with larger or more frequent boluses of insulin.
Working closely with your diabetes management team can help you to minimize any risks associated with pump use.
Careful and constant attention to diabetes self-management tasks is essential for any pregnant woman with diabetes. Those who want to use a pump during pregnancy must also be familiar with how to operate a pump and how to troubleshoot if pump problems arise.
Healthy eating. Eating for two doesn’t mean eating twice as many calories each day. The calorie needs for pregnancy range from 2400 to 2800 calories per day for most physically active pregnant women. This translates into approximately 300 extra calories a day—the amount found in a snack of cheese and crackers or yogurt with a piece of fruit.
Because your baby’s health is so closely tied to your food intake, you should strive to pack the most nutrition power you can into the foods you eat. It’s important to eat a healthy variety of foods from all the food groups. The table “Healthy Eating During Pregnancy” is a guide to the minimum number of daily servings from each food group to meet the needs of women following a 2400-calorie-per-day diet. It is based on the Diabetes Food Pyramid. The food groups marked with an asterisk (*) are sources of carbohydrate; your intake of these foods should be individualized based on your blood glucose levels.
Carbohydrate counting is an excellent method of meal planning during pregnancy. Carbohydrate is the primary nutrient that affects postprandial (after-meal) blood glucose level; fat and protein have less of an immediate effect. Consuming an adequate and consistent amount of carbohydrate helps to keep blood glucose levels in the recommended target range and is important in promoting a healthy pregnancy outcome. Food sources of carbohydrate include grains, vegetables, fruit, milk, and sweets. Work with your registered dietitian to plan a diet that has the correct amount of carbohydrate for your pregnancy. Generally, 40% to 45% of your total calories should come from carbohydrate, although that amount depends on your individual food needs, preferences, and blood glucose levels. A dietitian can determine the target amounts of carbohydrate you need at each meal and snack throughout the day.
Equally important to learning which foods are sources of carbohydrate is learning how to measure out proper portion sizes—to make sure you’re eating enough but not too much. You will also need to know how to make adjustments in your insulin doses based on the amount of carbohydrate you choose to eat. A typical insulin-to-carbohydrate ratio is 1 unit of fast-acting insulin for each 10–15 grams of carbohydrate consumed. However, this number is individual and can vary throughout your pregnancy. Self-monitoring of your blood glucose levels is key to using carbohydrate counting as a meal planning method while you are pregnant and pumping.
Changing insulin needs. The normal hormone production and weight gain that occur during pregnancy increase insulin resistance, causing a woman’s insulin needs to change during the pregnancy. As the graph “Insulin Requirements During Pregnancy” illustrates, insulin needs during the first several weeks of pregnancy are usually not different from those before conception. However, in the latter part of the first trimester, you may have a higher risk of hypoglycemia because of an increase in sensitivity to insulin, rapid fetal growth, and a reduction in eating associated with morning sickness. Around the 16th week of pregnancy, insulin requirements gradually climb because of increasing insulin resistance (due to weight gain) and increasing levels of hormones, including human placental lactogen (hPL), a form of “growth hormone” for the baby. During the last six months of pregnancy, basal and bolus insulin doses may need to be increased every 7–10 days.
Blood glucose monitoring. To keep tabs on increasing insulin requirements and facilitate adjustments, blood glucose self-monitoring should be done 7–10 times daily. Fasting, premeal, and bedtime blood glucose values can assist in evaluating basal insulin infusion requirements. Checking blood glucose values 1–2 hours after eating can determine the adequacy of your bolus amounts. Many women find that as pregnancy progresses they are up going to the bathroom at least once per night; some take advantage of that time to check their blood glucose. Too-high or too-low blood glucose levels in the middle of the night may signal a need for a basal rate adjustment.
Checking for ketones. In addition to blood glucose monitoring, pregnant women with diabetes are usually advised to do a urine ketone check every morning before eating and additionally if blood glucose is high (above 200 mg/dl) or if they are ill. Ketones are acid substances that collect in the bloodstream when the body is unable to break down glucose properly and begins using fat for energy. If the body cannot get rid of the ketones, they build up and can cause a condition called ketoacidosis. Ketones in the blood during pregnancy are associated with decreased intelligence in the baby. The best approach to preventing and treating ketones is to treat elevated blood glucose levels aggressively, to check for ketones when blood glucose is high, and to promptly use the treatment recommended by your diabetes management team if ketones are present.
Ketones may also occur when there isn’t enough glucose in the bloodstream. These so-called starvation ketones may happen to women with preexisting diabetes as well as to those with gestational diabetes. If there is not enough food (glucose) in your system to meet your needs and those of your baby, the body will resort to using fat for energy and consequently produce ketones. In this case, your medical team may advise you to increase the amount of calories and carbohydrate in your meals and snacks.
Prompt troubleshooting. As mentioned earlier, if insulin delivery by an insulin pump is disrupted for any reason, high blood glucose can occur quickly. In this case, prompt action is needed. An injection of rapid- or short-acting insulin is usually needed to lower blood glucose until delivery of insulin with the pump is resumed. The insulin pump should never be disconnected for any significant length of time unless under specific direction from the physician. Frequent blood glucose monitoring is helpful to quickly detect any otherwise undetected interruption in insulin infusion.
Hypoglycemia also requires prompt treatment. Symptoms of hypoglycemia include weakness, shakiness, sweating, and dizziness. If these symptoms occur, ideally you should check your blood glucose level to verify that it is low. If hypoglycemia is not corrected promptly, the blood glucose level may continue to drop, preventing your brain from functioning efficiently and in some cases leading to seizures or unconsciousness.
Treatment for hypoglycemia is usually the consumption of 15 grams of carbohydrate, the amount in about three glucose tablets, one tube of glucose gel, or 4 ounces of fruit juice. A hormone called glucagon, which is given by injection, is available by prescription to treat severe hypoglycemia when a person is unable to eat or drink a carbohydrate source. Discuss proper indications and use of glucagon with your diabetes management team.
Infusion site considerations
Because the skin has a tendency toward dryness during pregnancy, you may be more likely to experience irritation at your infusion site, possibly as a result of the adhesive on the infusion set, the material the infusion set is made of, or simply leaving a set in too long. Because irritation can lead to infection, meticulous care of the infusion site is necessary. You should change your infusion set every 24–48 hours and use your set changes as an opportunity to observe your skin and infusion site. If skin irritation occurs in spite of frequent infusion set changes, work with your diabetes team to determine the cause and treatment. As your pregnancy progresses, you may want to try an insertion site other than your abdomen, or you may want to try an infusion set requiring a different angle of insertion from your usual set.
When the baby arrives
Ideally, you should discuss blood glucose control during labor and delivery—both target goals and method of insulin delivery—with your endocrinologist before you go into labor. Because blood glucose in excess of 120 mg/dl will stimulate the fetal pancreas to produce insulin, making hypoglycemia in the baby a possibility after he or she is born, it is important that your blood glucose level be kept in a lower range. To free you from the responsibility of managing your insulin pump during this time, your endocrinologist may recommend disconnecting your insulin pump and starting an intravenous insulin drip instead. Insulin delivery via an insulin drip can be modified based on blood glucose readings. Typically, insulin requirements decrease to 0 at the onset of active labor. An intravenous glucose infusion can be used to maintain caloric requirements.
Insulin requirements generally remain very low or decrease immediately after delivery. However, the amount of insulin needed immediately after delivery may depend on the type of delivery. Labor leading to a vaginal delivery is an intense, active process that can cause lowering of blood glucose level in the mother. A cesarean section, on the other hand, is a surgical procedure, which can be stressful to the body and may raise the blood glucose level. In either case, a substantial weight loss occurs at delivery, and the pregnancy hormones that have raised blood glucose levels are diminished, so insulin pump basal rates and bolus amounts must be recalculated at that time. Talk with your physician about this process so you know what to expect. Frequent blood glucose monitoring is recommended to assist with individualizing pump rates and to accommodate other factors such as breast-feeding following delivery.
Breast-feeding has numerous benefits for infants, so unless there is a compelling reason not to, it is recommended for new mothers. Insulin pump therapy can offer flexibility when juggling an infant’s feeding schedule with your own meal plan. For one thing, it allows you to safely delay your own meals (and boluses) if the baby needs feeding when you usually eat. It also allows you to use a temporary (usually lowered) basal rate during feedings to avoid hypoglycemia, if necessary.
Are you a candidate for pump therapy?
Day-to-day diabetes management is largely up to you. Having an insulin pump does not relieve you of your diabetes self-management responsibilities. Consider these criteria for trying insulin pump therapy. If you choose an insulin pump, it is ideal to begin the therapy prior to becoming pregnant. This allows for learning and mastering the use of the pump while working to achieve optimal glycemic control before you become pregnant. If you are interested in using an insulin pump for diabetes management, work with your health-care team to assure you have a full understanding if pump therapy is right for you.