Pregnancy & Breastfeeding

Gestational Diabetes

November 20, 2010

If you managed to get through the first three months (or in my case, the first five) of mood swings, nausea, vomiting, forgetfulness, vivid dreams and everything else you had to endure; you may think you may think you can sit back, relax, indulge in all your food cravings and enjoy the rest of your pregnancy.

Until…

At 24-28 weeks your doctor may ask you to take this (trust me when I say this) HORRIBLE test. Ok, it’s not really all that bad. It is called a “Glucose Tolerance” test.

What does a Glucose Tolerance test entail?

For various reasons, your doctor may decide that you need to take a Glucose Tolerance test. In my case, there was ‘sugar’ in my urine and there is diabetes in my family. If your doctor determines that you should take the complete 3­hour glucose tolerance test, you will be asked to follow some special instructions in preparation for the test. The test will take the following format:

  • For 10 to 14 hours before the test you should not eat and not drink anything but water.
  • First, a blood sample will be drawn to measure your ‘fasting’ blood sugar level.
  • Then you will be asked to drink a full bottle of a glucose drink (100 grams). This glucose drink is extremely sweet and occasionally makes some people feel nauseated. I was ‘lucky’ enough to have them add lemon juice to my drink in order to make it ‘taste better’.
  • Finally, blood samples will be drawn every hour for 3 hours after the glucose drink has been consumed.

If two or more of your blood sugar levels are higher than the diagnostic criteria, you have Gestational Diabetes. This testing is usually performed at the end of the second or the beginning of the third trimester (between the 24th and 28th weeks of pregnancy) when insulin resistance usually begins.

What is Gestational Diabetes?

Diabetes of any kind is a disorder that prevents the body from using food properly. Normally, the body gets its major source of energy from glucose – a simple sugar that comes from foods high in simple carbohydrates (e.g., table sugar or other sweeteners such as honey, molasses, jams, soft drinks and cookies) or from the breakdown of complex carbohydrates such as starches (e.g., bread, potatoes and pasta).

After sugars and starches are digested in the stomach, they enter the blood stream in the form of glucose. The glucose in the blood stream becomes a potential source of energy for the entire body, similar to the way in which petrol in a service station pump is a potential source of energy for your car.

But, just as someone must pump the petrol into the car, the body requires some assistance to get glucose from the blood stream to the muscles and other tissues of the body. In the body, that assistance comes from a hormone called insulin.

Insulin is manufactured by the pancreas, a gland that lies behind the stomach. Without insulin, glucose cannot get into the cells of the body where it is used as fuel. Instead, glucose accumulates in the blood to high levels and is excreted into the urine through the kidneys.

Unlike women with Type I diabetes, women with gestational diabetes have plenty of insulin. In fact, they usually have more insulin in their blood than women who are not pregnant. However, the effect of their insulin is partially blocked by a variety of other hormones made in the placenta, a condition often called Insulin Resistance.

The placenta performs the task of supplying the growing foetus with nutrients and water from the mother’s circulation. It also produces a variety of hormones vital to the preservation of the pregnancy.

Ironically, several of these hormones such as oestrogen, cortisol, and human placental lactogen (HPL) have a blocking effect on insulin, a ‘contra insulin’ effect.

This contra insulin effect usually begins about midway (20 to 24 weeks) through pregnancy. The larger the placenta grows, the more these hormones are produced, and the greater the insulin resistance becomes. In most women the pancreas is able to make additional insulin to overcome the insulin resistance.

When the pancreas makes all the insulin it can and there still isn’t enough to overcome the effect of the placenta’s hormones, gestational diabetes results. If we could somehow remove all the placenta’s hormones from the mother’s blood, the condition would be remedied. This, in fact, usually happens following delivery.

How does gestational diabetes differ from other types of diabetes?

Gestational diabetes develops only during pregnancy. Though it usually disappears after delivery, the mother is at increased risk of getting type II diabetes later in life.

Who is at risk for developing gestational diabetes?

Any woman might develop gestational diabetes during pregnancy. Some of the factors associated with women who have an increased risk are obesity, a family history of diabetes, having given birth previously to a very large infant, a stillbirth, or a child with a birth defect or having too much amniotic fluid

Also, women who are older than 25 are at greater risk than younger individuals. Although a history of sugar in the urine is often included in the list of risk factors, this is not a reliable indicator of who will develop diabetes during pregnancy. Some pregnant women with perfectly normal blood sugar levels will occasionally have sugar detected in their urine.

How does gestational diabetes affect pregnancy and will it hurt my baby?

The complications of gestational diabetes are manageable and preventable. The key to prevention is careful control of blood sugar levels just as soon as the diagnosis of gestational diabetes is made.

One of the major problems a woman with gestational diabetes faces is a condition the baby may develop called ‘macrosomia’. Macrosomia means ‘large body’ and refers to a baby that is considerably larger than normal. All of the nutrients the foetus receives come directly from the mother’s blood. If the maternal blood has too much glucose, the pancreas of the foetus senses the high glucose levels and produces more insulin in an attempt to use the glucose.

The foetus converts the extra glucose to fat. Even when the mother has gestational diabetes, the foetus is able to produce all the insulin it needs. The combination of high blood glucose levels from the mother and high insulin levels in the foetus results in large deposits of fat which causes the foetus to grow excessively large, a condition known as macrosomia.

Occasionally, the baby grows too large to be delivered through the vagina and a caesarean delivery becomes necessary. The obstetrician can often determine if the foetus is macrosomic by doing a physical examination. However, in many cases a special test called an ultrasound is used to measure the size of the foetus.

In addition to macrosomia, gestational diabetes increases the risk of hypoglycaemia (low blood sugar) in the baby immediately after delivery. This problem occurs if the mother’s blood sugar levels have been consistently high causing the foetus to have a high level of insulin in its circulation. After delivery the baby continues to have a high insulin level, but it no longer has the high level of sugar from its mother, resulting in the newborn’s blood sugar level becoming very low.

Your baby’s blood sugar level will be checked in the newborn nursery and if the level is too low, it may be necessary to give the baby glucose intravenously. Infants of mothers with gestational diabetes are also vulnerable to several other chemical imbalances such as low serum calcium and low serum magnesium levels.

All of these are manageable and preventable problems. The key to prevention is careful control of blood sugar levels in the mother just as soon as the diagnosis of gestational diabetes is made. By maintaining normal blood sugar levels, it is less likely that a foetus will develop macrosomia, hypoglycaemia, or other chemical abnormalities.

What can be done to reduce problems associated with gestational diabetes?

In addition to your obstetrician, there are other health professionals who specialize in the management of diabetes during pregnancy including internists or diabetologists, registered dieticians, qualified nutritionists, and diabetes educators. Your doctor may recommend that you see one or more of these specialists during your pregnancy. It was recommended that I visit a dietician who helped me gain control of my ‘sugar’ levels without making me feel starved. It was actually quite a blessing in disguise as I lost any unnecessary weight and learnt about eating healthily while not feeling deprived.

One of the essential components in the care of a woman with gestational diabetes is a diet specifically tailored to provide adequate nutrition to meet the needs of the mother and the growing foetus. At the same time the diet has to be planned in such a way as to keep blood glucose levels in the normal range (60 to 120 mg/dl).

You may be asked to test your blood sugar levels at home to make sure that you are keeping your blood sugar in the normal range. The dietician tested my sugar levels every time I went and I was not asked to do home tests (luckily, as I am not a friend of the needle)

Is it ever necessary to take insulin?

Yes, despite careful attention to diet some women’s blood sugars do not stay within an acceptable range. A pregnant woman free of gestational diabetes rarely has a blood glucose level that exceeds 100 mg/dl in the morning before breakfast (fasting) or 2 hours after a meal. The optimum goal for a gestational diabetic is blood sugar levels that are the same as those of a woman without diabetes.

There is no absolute blood sugar level that necessitates beginning insulin injections. However, many doctors begin insulin if the fasting sugar exceeds 105 mg/dl or if the level 2 hours after a meal exceeds 120 mg/dl on two separate occasions.

Does gestational diabetes affect labour and delivery?

Most women with gestational diabetes can complete pregnancy and begin labour naturally. Any pregnant woman has a slight chance (about 5 percent) of developing preclampsia (toxaemia), a sudden onset of high blood pressure associated with protein in the urine, occurring late in pregnancy. If preclampsia develops, your obstetrician may recommend an early delivery. When an early delivery is anticipated, an amniocentesis is usually performed to assess the maturity of the baby’s lungs.

Gestational diabetes, by itself, is not an indication to perform a caesarean delivery, but sometimes there are other reasons your doctor may elect to do a caesarean. For example, the baby may be too large (macrosomic) to deliver vaginally, or the baby may be in distress and unable to withstand vaginal delivery. You should discuss the various possibilities for delivery with your obstetrician so there are no surprises. I landed up having a caesarean due to my baby’s stomach and shoulder growth but that does not mean you will need to go the same route.

Remember to:

  • Be open-minded
  • Not Stress

Careful control of blood sugar levels remains important even during labour. If a mother’s blood sugar level becomes elevated during labour, the baby’s blood sugar level will also become elevated. High blood sugars in the mother produce high insulin levels in the baby. Immediately after delivery high insulin levels in the baby can drive its blood sugar level very low since it will no longer have the high sugar concentration from its mother’s blood.

Women, whose gestational diabetes does not require that they take insulin during their pregnancy, will not need to take insulin during their labour or delivery. On the other hand, a woman who does require insulin during pregnancy may be given insulin by injection on the morning labour begins, or in some instances, it may be given intravenously throughout labour. For most women with gestational diabetes there is no need for insulin after the baby is born and blood sugar level returns to normal immediately. The reason for this sudden return to normal lies in the fact that when the placenta is removed the hormones it was producing (which caused the insulin resistance) are also removed. Thus, the mother’s insulin is permitted to work normally without resistance. Your doctor may want to check your blood sugar level the next morning, but it will most likely be normal.

Should I expect my baby to have any problems?

One of the most frequently asked questions is, ‘Will my baby have diabetes?’ Almost universally, the answer is no. However, the baby is at risk for developing Type II diabetes later in life and of having other problems related to gestational diabetes, such as hypoglycaemia (low blood sugar) mentioned earlier.

If your blood sugars were not elevated during the 24 hours before delivery, there is a good chance that hypoglycaemia will not be a problem for your baby. Nevertheless, a neonatologist (a doctor who specializes in the care of newborn infants) or other doctor should check your baby’s blood sugar level and give extra glucose if necessary.

Another problem that may develop in the infant of a mother with gestational diabetes is jaundice. Jaundice occurs when extra red blood cells in the baby’s circulation are destroyed, releasing a substance called bilirubin. Bilirubin is a pigment that causes a yellow discoloration of the skin (jaundice). A minor degree of jaundice is common in many newborns. However, the presence of large amounts of bilirubin in the baby’s system can be harmful and requires placing the baby under special lights which help get rid of the pigment. In extreme cases, blood transfusions may be necessary.

Will I develop diabetes in the future?

For most women gestational diabetes disappears immediately after delivery. However, you should have your blood sugars checked after your baby is born to make sure your levels have returned to normal. Women who had gestational diabetes during one pregnancy are at greater risk of developing it in a subsequent pregnancy. It is important that you have appropriate screening tests for gestational diabetes during future pregnancies as early as the first trimester.

Pregnancy is a kind of ‘stress test’ that often predicts future diabetic problems. In one large study more than one half of all women who had gestational diabetes developed overt Type II diabetes within 15 years of pregnancy. Because of the risk of developing Type II diabetes in the future, you should have your blood sugar level checked when you see your doctor for your routine check­ups. There is a good chance you will be able to reduce the risk of developing diabetes later in life by maintaining an ideal body weight and exercising regularly.

Gestational Diabetes and Exercise

A daily exercise program is an important part of a healthy pregnancy. Daily exercise helps you feel better and reduces stress. In addition; being physically fit protects against back pain and maintains muscle tone, strength and endurance. For women with gestational diabetes, exercise is especially important.

Regular exercise increases the efficiency or potency of your body’s own insulin. This may allow you to keep your blood sugar levels in the normal range while using less insulin.

Moderate exercise also helps reduce your appetite, helping you to keep your weight gain down to normal levels. Maintaining the correct weight gain is very important in preventing high blood sugar levels.

Don’t omit a warm-up period of 5 to 10 minutes and a cool-down period of 5 to 10 minutes. Always stop exercising if you feel pain, dizziness, shortness of breath, faintness, palpitations, back or pelvic pain or experience vaginal bleeding.

If you need to be on insulin during your pregnancy, take a few precautions. Because both insulin and exercise lower blood sugar levels, the combination can result in hypoglycaemia or low blood sugar. You need to be aware that this is a potential problem, and you should be familiar with the symptoms of hypoglycaemia (confusion, extreme hunger, blurry vision, shakiness, sweating).

When exercising, take along sugar in the form of hard, sugar-sweetened candies just in case your blood sugar becomes too low. When on insulin, you should always carry some form of sugar for potential episodes of hypoglycaemia.

I hope this information has been helpful. There are already so many concerns that arise when you find out your are pregnant, equipping yourself with information and a good doctor is the best thing that you can do.

Leave a Reply