Gestational diabetes (GDM) is a common pregnancy complication. In fact, depending upon ethnicity, as many as 5-10% of women will have some form of diabetes in pregnancy. What are signs of gestational diabetes? What are gestational diabetes symptoms? What is an ideal diet for gestational diabetes? What are the complications of GDM? These are common questions to the Ob/Gyn.
There are several types of diabetes that can affect pregnancy. Some women will have diabetes develop as a direct result of the pregnancy, this is called "gestational diabetes". This is because the placenta secretes hormones that drive sugars upward, to guarantee a stable sugar supply to the developing fetus. If women have some degree of decreased insulin sensitization, they body cannot keep these signals in check, a woman's sugars become too high, and she develops GDM. There are relatively few signs of gestational diabetes or gestational diabetes symptoms. Increased thirst and urination, yeast infections, fatigue are the most common gestational diabetes symptoms. Therefore, testing only when there are signs of gestational diabetes symptoms simply isn't helpful, all women should be screened for gestational diabetes. Even those without signs of this disease. Women with a history of gestational diabetes, a large baby, a strong family history of diabetes, obesity, and advanced maternal age are at higher risk for gestational diabetes. Usually we screen these women for gestational diabetes early when they present for prenatal care, and then at 26-28 weeks, a high risk time for the development of gestational diabetes.
Some women have underlying diabetes when they get pregnant. In general, this is divided into two categories: Type I diabetes and Type II diabetes. Type I diabetes results from a failure of the pancreas to make insulin. These patients must be treated with insulin to prevent becoming acidotic, which can be life-threatening. Type II diabetic patients have high sugar because their body becomes insensitive to the effects of insulin. This is strongly associated with obesity, and therefore the incidence of Type II diabetes is increasing substantially in the Western World. Eventually, if uncontrolled, these forms of diabetes can cause kidney disease, high blood pressure, retinal disease and blindness, heart disease, vascular disease, etc.. Often times a pregnant woman may be diagnosed for the first time in pregnancy, because she has not been tested before the pregnancy. Usually, if diabetes is diagnosed before 22 weeks it is felt it likely represents underlying disease that will remain after the pregnancy ends.
There are multiple effects of GDM in pregnancy. The placenta will drive sugars upwards, and therefore as the pregnancy progresses women are more likely to have higher sugars and need more medication and a stricter gestational diabetes diet to keep their sugars in the normal range. This increase occurs until about 36-37 weeks, when a plateau usually occurs.
In addition, in women with underlying diabetes, complications for their diabetes can worsen in the pregnancy. Blood pressure disorders often worsen, and can become quite severe, placing both the mom and fetus at risk. Retinal disease can worsen, although this usually is temporary. Similarly, renal disease can worsen, but again it seems to correct after the pregnancy. If a patient has heart disease from the diabetes this can become very dangerous because of the added stress the pregnancy puts on the heart, especially near the time of delivery. Therefore any woman who is pregnant and has had diabetes for over 10 years, or has underlying known heart disease, or is over 40 years old should have baseline heart studies (such as an EKG and echocardiogram) done during the pregnancy.
Women with underlying diabetes are also at increased risk for pregnancy specific complications. They are at increased risk for preeclampsia or toxemia of pregnancy (see link below for more information). For this reason we recommend a full baseline work-up including a 24 hour urine collection be done early in the pregnancy. They are also at increased risk for both large fetuses and traumatic delivery, as well as growth restricted fetuses (see link below for more information). Large fetuses result from high levels of insulin, and high sugar levels during the pregnancy. Growth restriction of the fetus can occur because of underlying disease in the blood vessels that supply the placenta and therefore the baby. Fetal growth restriction is usually a complication of Type I and longstanding Type II diabetes. In addition, women with underlying diabetes are at increased risk for stillbirth, and therefore the fetal growth should be followed closely, and we typically recommend close fetal surveillance with testing the last 4-6 weeks of pregnancy. In addition, going beyond your due date adds an additional risk for stillbirth and therefore induction by the due date should be considered.
In addition, fetuses born to women with underlying diabetes are at increased risk for birth defects. Defects of the heart and spine, and truly every organ system are higher in patients with poorly controlled diabetes prior to conception. This effect is directly related to sugar control, and the better sugar control is prior to conception, the lower the rate of birth defects in the fetus. Conversely, women with very poor control have greatly increased rates of anomalies, which can skyrocket to 20-25% of fetuses. Therefore, any diabetic woman considering pregnancy should optimize her sugars for several weeks prior to attempting conception to decrease the rate of having a baby with a birth defect.
The major complication of GDM is macrosomia, or a large fetus. When sugars are poorly controlled fetuses can grow abnormally large. This is why following a diet for gestational diabetes and even medications to control high sugars are so important. This presents many problems. Commonly this can make delivery very difficult, and even very dangerous for the baby and the mom. The baby can "get stuck" after the delivery of the head, a situation we call "shoulder dystocia". This more commonly happens in women with gestational diabetes because their fetal chest and abdomen sizes are larger than the head. Ideally, the hardest thing to deliver should be the head, and usually it is. If you have poorly controlled gestational diabetes, then the belly of the baby can be the hardest thing to deliver which can quickly become very dangerous. When this occurs, injury to the fetus can result from the maneuvers necessary to facilitate delivery. If these maneuvers fail, the baby's life can become threatened by lack of oxygen, and rarely fetal death can occur. In addition, the difficult delivery can be quite traumatic to mom, and a substantial repair is common. We have tried for decades to figure out ways to predict when this will occur, and there simply are no good predictors known at this time. Typical recommendations are to consider elective Cesarean delivery if fetal weight is believed to be greater than 4500 gm in women with gestational diabetes.
The most important management of gestational diabetes is following a gestational diabetes diet and exercise. If these fail, we have made considerable advances on therapies for diabetes in pregnancy. Improved medical therapies, including insulin, glyburide and currently being studied- metformin, have improved sugar control in pregnancy (see www.AskAnOB.com/gestationaldiabetestreatment for more information). Improved sugar control, increased use of ultrasound and testing, and better overall care of diabetic patients have substantially improved outcomes. If you have been diagnosed with gestational diabetes take care of yourself and your baby!
GESTATIONAL DIABETES DIET:
-- Eat several small meals instead of large meals.
-- Reduce the amount of simple sugars (sweets) and complex carbohydrates (pasta, bread) in your diet.
-- Add foods high in fiber (multigrain bread, brown rice) in place of other carbs.
-- Increase the amount of vegetables in your diet.
-- If you eat a "culprit food" for instance, milk, drink smaller amounts than you usually would and be consistent! Your doctor can adjust your medications, but there must be a PATTERN. So if you like to have milk with your breakfast, just make sure you do less than you normally would, and do it everyday.
-- Avoid fast food at all costs. If it comes in a wrapper, it isn't for you! It may be easy, but the price you pay in the long run simply isn't worth it.
-- Try to be consistent in the timing of your meals. The hardest thing to do is chase inconsistency.
-- Track your diet and your sugars carefully. This really becomes a full-time job in pregnancy, but is key to your success. This will enable your doctor to optimize your treatment.
-- EXERCISE, EXERCISE, EXERCISE. You can do alot with a gestatioanal diabetes diet alone, but you will be amazed at how a little walking helps your sugars. Find ways to do exercise in your everyday life: park further away, take the stairs up a flight or two, walk to the local store/park/friends instead of driving.
Look at this complication of pregnancy as a window of opportunity to make healthy lifestyle changes. Watch your diet, exercise regularly, and be compliant with sugar checks and medications to give you and your baby the best chance for a good outcome!
|
