Pregnancy can be a special and exciting time in a woman's life. The anticipation begins as soon as you hear the words: “You're expecting a baby.” Once you've gotten used to the amazing news, you may wonder about such things as whether the baby will be a boy or a girl, when the baby is due, and, perhaps most important, what you need to do in the meantime to make sure the baby stays healthy and develops normally.
All women feel a certain amount of anxiety and sometimes even fear about how pregnancy will affect them, and whether their baby will be healthy and normal. Women with diabetes are no different, but they do have one more thing to be concerned about: maintaining control of blood glucose levels. This is true whether a woman has type 1 or type 2 diabetes before becoming pregnant, or whether she is diagnosed with a condition called gestational diabetes during pregnancy. The good news is that if a woman who has diabetes (of any type) learns as much as she can about managing her blood glucose, and puts that knowledge into practice, she can have a healthy pregnancy and a healthy baby.
Optimal blood glucose control is important throughout pregnancy, both for the mother's health and the baby's. Glucose in a mother's blood crosses the placenta to her baby, affecting the baby's blood glucose level. (The placenta, a flat circular organ, links the unborn baby to the mother's uterus, to provide oxygen, nutrients, and the elimination of wastes.) The baby begins making its own insulin around 13 weeks gestation. If the baby is constantly exposed to high levels of glucose, it is as if the baby were overeating: The baby produces more insulin to absorb the excess glucose, resulting in weight gain and an increase in size. Under these conditions, the baby can become too large, a condition known as macrosomia. Macrosomia is associated with difficult vaginal delivery, which can lead to birth injury and/or asphyxia, a condition in which the baby doesn't get enough oxygen.
Another reason that blood glucose control is important right up to the day of delivery is that if an unborn baby has high levels of insulin on a consistent basis, or if the mother's blood glucose level is high during labor, the baby may experience hypoglycemia (low blood sugar) or other complications when the umbilical cord (and the maternal blood supply) is cut.
The details of managing blood glucose levels during pregnancy may be different for women who already have either type 1 or type 2 diabetes before pregnancy and for those who are diagnosed with diabetes during pregnancy, or gestational diabetes. (These differences are covered later in this article.) The recommended blood glucose goals, however, are the same.
It is important to note that the blood glucose goals suggested by the American Diabetes Association (ADA) for pregnant women are lower than those for the general population with diabetes. (See sidebar: “Blood Glucose Goals During Pregnancy.”) In addition, the ADA suggests that pregnant women check their blood glucose levels up to eight times per day: once before each meal, again one hour after each meal, at bedtime, and once in the middle of the night. (Any woman who is taking insulin or certain kinds of blood glucose-lowering pills would need to do additional checks before driving, and if she experienced any symptoms of low blood sugar.) Your health-care team may recommend a somewhat different monitoring schedule depending on the type of diabetes you have and how you treat it. However, frequent self-monitoring is needed to ensure that blood glucose levels remain within the recommended range.
In addition to blood glucose monitoring, daily urine ketone testing is often
advised for pregnant women with diabetes. Ketones are acid substances that collect
in the bloodstream if the body is unable to break down glucose for energy. This
can occur if there is not enough insulin to break down glucose in the bloodstream
or if there is not enough glucose available to meet energy needs. In either
case, the body begins to use stored fat for energy, a process that yields the
acidic byproducts called ketones. If the body is unable to get rid of the ketones
fast enough (via the lungs and urine), they build up, and can cause a potentially
deadly condition called ketoacidosis.
Ketones in the blood during pregnancy are associated with decreased intelligence in the baby, and an episode of ketoacidosis during pregnancy greatly increases the risk of the fetus dying in the uterus. Diabetic ketoacidosis may develop rapidly, and at lower blood glucose levels in women who are pregnant than in those who are not. The best approach for preventing this outcome is to closely monitor blood glucose levels outside the recommended range for pregnancy, and to promptly treat elevated blood glucose levels, as directed by your diabetes management team. Notify your diabetes health-care team immediately if you detect ketones in your urine and have a high blood glucose level.
Ketones that occur when there isn't enough glucose in the bloodstream are called “starvation ketones.” They may occur in women with gestational diabetes, as well as in those with type 1 or type 2 diabetes. A woman with starvation ketones would typically have a blood glucose reading in the normal range or lower than normal. If you are getting starvation ketones, your medical team may advise you to increase the amount of calories and carbohydrate in your meals and snacks.
During your pregnancy, if you are not already seeing an endocrinologist, your obstetrician may refer you to one. Most likely, you would see the endocrinologist at least once a month during the first and second trimesters (approximately the first six months of pregnancy) and every two weeks in the third trimester (the last three months). In addition to your scheduled appointments, you should discuss specific guidelines for prompt follow-up if blood glucose levels are not staying within recommended ranges. Your obstetrician will likely evaluate the growth and condition of your baby throughout your pregnancy with tests such as ultrasound to monitor your baby's size and the non-stress test, which measures a baby's heart rate in response to his or her own movements. Additional testing to monitor your baby's health, or yours, may be recommended by your obstetrician or by members of your diabetes health-care team.
During any pregnancy, a woman's insulin needs change, because the normal hormone production and weight gain that occur during pregnancy increase insulin resistance. (See sidebar: “Insulin Requirements During Pregnancy.”) In women who do not have or develop diabetes, blood glucose levels remain stable because the pancreas is able to produce more insulin to accommodate the increased demand. In women with preexisting diabetes, or who develop gestational diabetes, the pancreas cannot keep up with the increased demand, so blood glucose levels rise unless steps are taken to lower them.
In women with preexisting diabetes, insulin needs during the first several weeks of pregnancy are not usually that different from those before conception. However, in the latter part of the first trimester, women with preexisting diabetes 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 needs gradually increase, due to increasing levels of hormones, including human placental lactogen (hPL), a form of “growth hormone” for the baby.
All women with type 1 diabetes, and most with type 2 either inject or infuse insulin during pregnancy. Women with gestational diabetes also have to take steps to control their blood insulin level, but not all will have to inject insulin. Some women with gestational diabetes can keep their blood glucose at recommended levels with changes in diet and moderate exercise. Many, however, must eventually use insulin.
In women with type 1 or type 2 diabetes, optimal blood glucose control is essential prior to conception, because it is hard to be absolutely certain of when conception takes place. The incidence of fetal malformations is reduced significantly in women who have near-normal glycosylated hemoglobin (HbA1c) levels before they become pregnant. The rate of miscarriage in women with preexisting diabetes is also reduced by keeping blood glucose as close to normal as possible in the first trimester.
Ideally, you should strive for a near-normal HbA1c test result at least three
months prior to pregnancy. It is important to discuss any plans to become pregnant
with your diabetes health-care team, particularly if you have vascular complications
related to your diabetes, such as eye or kidney disease. In this situation,
pregnancy is a potential risk to your health. For women with no vascular complications,
a thorough physical exam, good nutrition (including a folic acid supplement),
and excellent blood glucose control before you become pregnant will help minimize
any health risks to you and your baby. Be sure you are using a reliable method
of birth control, as you work toward optimal blood glucose levels.
Gestational diabetes is a form of glucose intolerance (difficulty metabolizing blood glucose) that is first recognized during pregnancy. It affects almost 7% of all pregnancies. Factors that may contribute to a high risk of gestational diabetes include overweight, a history of gestational diabetes with a prior pregnancy, GLYCOSURIA (glucose in the urine, which would be found in a routine urine test) and a strong family history of diabetes. In addition, women who are African-American, Hispanic, or from certain Native American groups, as well as women with polycistic ovary syndrome (PCOS) have shown a higher risk for gestational diabetes.
Screening tests should be recommended between 24 and 28 weeks gestation for any woman considered at risk of gestational diabetes by her obstetrician. These tests usually involve drinking a pre-measured glucose solution, and then having blood samples drawn and checked for glucose level, to determine if the body tolerates the glucose load normally. Test levels that are out of the normal range may indicate that the mother's blood glucose levels are likely to rise as the pregnancy progresses.
If you are diagnosed with gestational diabetes, your obstetrician may refer you to a diabetes educator or to an endocrinologist (or both), for help managing your diabetes and your pregnancy. Because blood glucose control is essential during pregnancy, weekly follow-ups with the health professional managing your diabetes are usually recommended.
Most cases of gestational diabetes disappear after delivery because two of the primary factors that contribute to insulin resistance and high blood glucose levels are either diminished (the extra weight gained during pregnancy) or gone (the hormones produced by the placenta). If your blood glucose levels were normal prior to the pregnancy, they will most likely return to normal after delivery. However, once you have had gestational diabetes, you are likely to develop it again in another pregnancy. You also face a greater risk for developing type 2 diabetes later in life.
The tools used to maintain blood glucose control during pregnancy
are the same tools used to control any case of diabetes. They include a meal
plan, an exercise plan, and possibly an insulin plan.
Meal plan. Whether you have preexisting diabetes or gestational diabetes, you
should work with a registered dietitian to design an individualized meal plan
for your pregnancy. The plan should focus on foods that provide good nutrition
for you and your baby, and that help keep your blood glucose level in the desired
range. Because carbohydrate has the most immediate impact on blood glucose levels,
your meal plan should specify how much carbohydrate to eat and when to eat it.
Carbohydrate is found mainly in foods such as breads, cereals, pasta, starchy
vegetables, fruits, and sweets. Frequent blood glucose monitoring will help
you determine the appropriate amount and timing of carbohydrate.
Your dietitian can also suggest how many calories you need each day based on your recommended weight gain. The amount of weight you should gain during pregnancy depends on your weight before pregnancy. In general, a woman at a healthy weight before pregnancy should gain 25 to 35 pounds during her pregnancy. Your health-care team may advise you to gain more if you are underweight, or less, if you are overweight. Keep in mind, however, that pregnancy is definitely not a time to try to lose weight. Most mothers require about 100 extra calories per day during the first trimester and an additional 300 calories per day during the remainder of the pregnancy to ensure the ideal weight gain for the mother and birth weight for the baby. (See sidebar: “Weight Gain During Pregnancy,” which illustrates how pregnancy weight gain is distributed.)
In most cases, your dietitian will recommend that you eat three meals a day with two to four between-meal snacks. An evening snack is particularly important to prevent hypoglycemia during the night and urine ketones or nausea in the morning.
You may be concerned about the safety of consuming sugar substitutes during pregnancy. At this time, research shows that the four most commonly used sugar substitutes (acesulfame-K, aspartame, saccharin, and sucralose) are safe to use in moderation during pregnancy. Some of these sweeteners do cross the placenta, and can reach the baby, but there is no evidence they cause ill effects. If in doubt, follow the advice of your obstetrician.
For more specifics on the components of a well-balanced diet
during pregnancy, see sidebar: “Eating for Two.”
Regular physical activity is essential to diabetes control and to general health and well-being Your health-care team can help you determine a safe level of exercise for you during pregnancy. If you have always exercised in the past, you may be able to continue to exercise at a more moderate level while you are pregnant. If exercise was not part of your pre-pregnancy routine, check with both your obstetrician and endocrinologist before you start, and choose an activity such as brisk walking or swimming, to incorporate into your daily routine. Because exercise usually lowers blood glucose, be alert to the symptoms of hypoglycemia, and check your blood glucose level before and after you exercise.
Insulin management. Insulin is the most common medicine used for blood glucose control during pregnancy. Blood glucose-lowering pills are used much less often because of a lack of data on their safety. However, at least one recent study concluded that glyburide (brand names DiaBeta, Glynase PresTab or Micronase), when taken by women with gestational diabetes during the last six months of pregnancy, did not change fetal outcome.
Women with type 1 diabetes may prefer to stick with their usual insulin delivery method during pregnancy, or they may decide to try something new, such as insulin pump therapy. For some, using a pump during pregnancy allows them to fine-tune their insulin requirements.
Women with type 2 diabetes who take pills as part of their diabetes treatment plan are usually advised to switch to insulin during pregnancy. In fact, many health care practitioners recommend that women with type 2 diabetes switch to insulin therapy before becoming pregnant. This may help them adjust to insulin therapy and possibly allow them to bring their blood glucose levels into the ranges recommended during pregnancy before they become pregnant.
As mentioned earlier, women with gestational diabetes usually start by seeing how well dietary changes control their blood glucose levels, and then add insulin if blood glucose levels do not stay within recommended ranges. Women who must learn to use insulin because of gestational diabetes may find that using an insulin pen is easier than using a syringe. Using premixed insulins, rather than mixing your own, may also simplify your diabetes management.
The most common side effect of insulin therapy is hypoglycemia. Once insulin enters the body and begins working, blood glucose levels may drop lower than recommended if you do not eat to balance the effects, or if you exercise too much. Women using insulin during pregnancy should make sure they receive information about the warning signs and treatment of hypoglycemia. In addition, they should be aware that hypoglycemia unawareness (the inability to detect early signs of low blood glucose) may be more common in pregnant women, especially those with type 1 diabetes.
Most physicians prefer that women with diabetes deliver as close to their due date as possible. Babies delivered after their due date tend to be larger and risk more complications. If natural labor is not timely, and a woman plans to deliver vaginally, a hormone called oxytocin can be given, usually intravenously, to induce labor. If a woman is scheduled for caesarian section, oxytocin is not necessary.
Many women with diabetes are able to deliver vaginally. A caesarian section may be needed if the baby is too large (macrosomic), if the woman's pelvis is too small, or if a woman has vascular complications or blood pressure problems. A caesarian delivery may also be required if a baby is in the breech position (when the baby's feet or buttocks enter the birth canal first).
Labor is an intense, active process, which can lower a woman's blood glucose level. A caesarian delivery, on the other hand, may raise a woman's blood glucose level, because the surgical procedure is a stress on the body. If you have type 1 or type 2 diabetes, your doctor may have you on insulin intravenously during labor and delivery. The IV apparatus continuously infuses quick-acting insulin, and may allow for smoother blood glucose control, since adjustments can be made as necessary. The goal is to keep blood glucose levels as normal as possible to prevent hypoglycemia in your newborn. Most women with gestational diabetes do not require any insulin during the labor and delivery process. After delivery, continuing to maintain blood sugar levels in a near-normal range facilitates the healing process.
If you have type 1 or type 2 diabetes, your insulin requirements may return to what they were before your pregnancy within a few weeks of delivery. Check your blood glucose levels frequently, and make adjustments to your insulin dosage as needed.
If you had gestational diabetes, it is likely that your blood glucose level will return to normal almost immediately after your baby is born. But since gestational diabetes puts you at increased risk for developing type 2 diabetes in the future, you should have your blood glucose level measured at your first postpartum checkup (usually four to six weeks after delivery) and yearly thereafter. To minimize your risk of developing type 2 diabetes, eat a balanced diet, exercise regularly, and keep your weight at a reasonable level.
If you decide to breast-feed, speak with a registered dietitian about the foods you need to ea , so you will get enough calcium, fluids, and protein. Breast-feeding increases a woman's caloric needs, and, because it takes energy, may increase her risk of hypoglycemia. Episodes of hypoglycemia are more likely to occur within an hour after breast-feeding, so this is an important time to check your blood glucose level. Napping after meals and snacks is also recommended to lower the risk of hypoglycemia. You may need to adjust your insulin dosage, particularly overnight, to prevent your blood glucose level from dropping during late-night feedings.
Women with type 2 diabetes who switched from oral pills to insulin during pregnancy are generally encouraged to stay on insulin for at least a month after delivery. For many of the newer diabetes drugs, little or no research has been done on their use in breast-feeding women.
Tough job, big rewards
Managing your diabetes during pregnancy means paying extra attention to your lifestyle during these important months. Though you may feel overwhelmed at times, your health-care team is available to answer your questions and help you attain excellent blood glucose control. The commitment you make now will pay off with the best results in the future: a healthy, happy baby, and a healthy you.
Laura Hieronymus and Patti Geil are Certified Diabetes Educators
in an ADA-recognized education service in Lexington, Kentucky. They counsel
in the area of diabetes and pregnancy management, with Kristina Humphries, MD.
Reprinted with permission from DIABETES SELF-MANAGEMENT. Copyright ©2001,
R.A. Rapaport Publishing, Inc. For subscription information, call: 1-800-234-0923.
Ever wonder why pregnancy usually involves gaining at least
25 pounds, when a baby usually weighs only 7 or 8? Here's a breakdown of what
accounts for the other 17 or more pounds
WHAT POUNDS
__________________________________________
Developing
unborn baby 7-8
__________________________________________
Placenta 1-2
__________________________________________
Amniotic fluid 2
__________________________________________
Uterus 2
__________________________________________
Increase in
blood volume 3
__________________________________________
Breasts 1
__________________________________________
Body fat 5 or more
__________________________________________
Increased muscle
tissue and fluid 4-7
__________________________________________
TOTAL: 25 or more
__________________________________________
The American Diabetes Association's recommended goals for blood glucose during pregnancy are even closer to the normal non-diabetic range than for the general population with diabetes. These goals have been set with the health of both mother and developing baby in mind.
WHEN WHOLE BLOOD PLASMA VALUE
Fasting 60-90 Mg/dl 69-104 Mg/dl
Before meals 60-105 Mg/dl 69-121 Mg/dl
1 hour after meals
100-120 Mg/dl 115-138 Mg/dl
2 AM-6 AM 60-120 Mg/dl 69-138 Mg/dl
For more information on diabetes and pregnancy, you may find the following resources helpful.
Books published by the American Diabetes Association can be purchased via the Internet (http://store.diabetes.org/adabooks) Or by calling, toll-free: 1-800-232-6733.
DIABETES AND PREGNANCY: WHAT TO EXPECT (2000) American Diabetes Association
GESTATIONAL DIABETES: WHAT TO EXPECT (2000) American Diabetes Association
These brochures can be read online, or ordered by phone, using the toll-free numbers listed below.
DIABETES AND PREGNANCY, Juvenile Diabetes Research Foundation, telephone: 1-800-533-2873; website: www.jdf.org/jdfliving/pages/pregnancy.html
UNDERSTANDING GESTATIONAL DIABETES: A Practical Guide to a Healthy Pregnancy, National Institute of Child Health and Human Development; telephone: 1-800-370-2943; website: www.nichd.nih.gov/publications/pubs/gesttoc.htm
Eating enough of the right foods is one of the most important things you can do to ensure your baby is healthy. Although nutrient needs increase during pregnancy, most women can meet these needs by eating a balanced diet that includes a variety of foods. However, for some women, prenatal vitamin and mineral supplements, particularly iron, may be necessary. When planning your meals during pregnancy, pay special attention to the following nutrients:
Pregnant women require an extra 10 grams of protein daily (or a total of 60
grams daily) for a healthy baby and placenta. A three-ounce serving of meat
provides approximately 20 grams of protein.
The requirements for B vitamins increase during pregnancy; B vitamins help to metabolize the energy from food and help protein to make new body cells. Getting adequate amounts of a B vitamin called folate, or folic acid, is particularly important in the first three months of pregnancy. Consuming enough folate before pregnancy and in the early stages may lower the risk of neural tube birth defects (birth defects that involve the spinal column) in the baby. Pregnant women require 600 micrograms of folate daily. A half-cup serving of boiled navy beans provides 125 micrograms of folate.
Calcium is critical for preserving a mother's bone mass while the baby's skeleton develops. Pregnant women need 1,000 milligrams of calcium daily. An eight-ounce glass of milk provides 300 milligrams of calcium.
Iron is essential in making hemoglobin, a blood component that
carries oxygen through the body to the placenta. It can be difficult to get
enough iron in the diet because it is not well absorbed from food, and many
women start pregnancy with low iron stores. Pregnant women require 27 milligrams
of iron daily. A three-ounce serving of lean beef has almost 3 milligrams of
iron.