Gestational diabetes is a type of diabetes that happens during pregnancy. Unlike type 1 diabetes, gestational diabetes is not caused by having too little insulin. Instead a hormone made by your placenta keeps your body from using the insulin as it should. This is called insulin resistance. Blood sugar (glucose) then builds up in your blood instead of being absorbed by the cells in your body.
The symptoms of gestational diabetes usually go away after delivery. But sometimes they do not, or you may have a greater risk of developing type 2 diabetes later.
Healthcare providers do not know what causes gestational diabetes, but they do know what happens.
The placenta gives your growing baby nutrients and water. The placenta also makes several hormones to keep the pregnancy healthy. These hormones include:
These hormones can affect how your body uses insulin (contra-insulin effect). This usually begins about 20 to 24 weeks into your pregnancy and could lead to gestational diabetes.
During pregnancy, more fat is stored in your body, you take in more calories, and you may get less exercise. All of these things can make your blood sugar (glucose) levels higher than normal and possibly lead to gestational diabetes.
As the placenta grows, it makes more of the hormones. The risk for insulin resistance becomes greater. Normally your pancreas is able to make more insulin to overcome insulin resistance. But if it cannot make enough to overcome the effects of the placenta’s hormones, you can develop gestational diabetes.
Any woman can develop gestational diabetes during pregnancy. But you may be more likely to get it if you:
Gestational diabetes does not cause any symptoms. That’s why it’s important to get tested for it if you are at high risk.
If your blood sugar levels are very high, you may have these symptoms:
You should be tested for gestational diabetes in your 24th to 28th week of pregnancy.
The American Diabetes Association also recommends that you be tested for type 2 diabetes if you have risk factors for this condition. This testing should be done at your first prenatal visit.
Screening is done by these tests:
If you are diagnosed with gestational diabetes, you should get tested for diabetes 4 to 12 weeks after your baby is born. You should also get this screening at least every three years for the rest of your life.
Your healthcare provider will figure out the best treatment for you based on:
Treatment for gestational diabetes focuses on keeping your blood sugar levels in the normal range. Treatment may include:
Gestational diabetes usually does not cause birth defects. But it can affect your baby in other ways if your blood sugar levels are not under control.
Below are the two major health problems that can develop.
Macrosomia means a baby who is much larger than normal. This happens if the mother’s blood has too much blood sugar in it. The fetus’ pancreas senses this high level of blood sugar and makes more insulin. The fetus then changes the extra blood sugar into fat. This extra fat means a larger baby.
A larger than normal baby can be difficult to deliver. The baby may have trauma or nerve damage, or need to be delivered by cesarean section.
Hypoglycemia is low blood sugar. This can happen to the baby just after he or she is born if the mother’s blood sugar levels are too high. The high levels in the mother cause the fetus to make more insulin. Once the baby is born, he or she no longer has the high blood sugar levels from the mother. This causes the baby’s blood sugar levels to fall very low.
Your blood sugar levels will be watched very closely during labor. Your healthcare provider may give you insulin to keep your blood sugar in a normal range. This will prevent your baby's blood sugar from dropping greatly after delivery.
Babies born to mothers with gestational diabetes may also have low levels of calcium or magnesium in their blood.
These complications can be prevented. The key to prevention is careful control of your blood sugar levels just as soon as the diagnosis of diabetes is made.