Gestational diabetes develops during pregnancy (gestation). Like other types of diabetes, gestational diabetes affects how your cells use sugar (glucose). Gestational diabetes causes high blood sugar that can affect your pregnancy and your baby’s health. Between 2 and 10 percent of expectant mothers develop this condition, making it one of the most common health problems of pregnancy.
Diabetes is complicated, but in a nutshell it means you have abnormally high levels of sugar in your blood. Here’s what happens:
When you eat, your digestive system breaks most of your food down into a type of sugar called glucose. The glucose enters your bloodstream and then, with the help of insulin (a hormone made by your pancreas), your cells use the glucose as fuel. However, if your body doesn’t produce enough insulin – or your cells have a problem responding to the insulin – too much glucose remains in your blood instead of moving into the cells and getting converted to energy.
When you’re pregnant, hormonal changes can make your cells less responsive to insulin. For most moms-to-be, this isn’t a problem: When the body needs additional insulin, the pancreas dutifully secretes more of it. But if your pancreas can’t keep up with the increased insulin demand during pregnancy, your blood glucose levels rise too high, resulting in gestational diabetes.
Any pregnancy complication is concerning, but there’s good news. Expectant moms can help control gestational diabetes by eating healthy foods, exercising and, if necessary, taking medication. Controlling blood sugar can prevent a difficult birth and keep you and your baby healthy.
In gestational diabetes, blood sugar usually returns to normal soon after delivery. Once you’ve had gestational diabetes, though, you’re at higher risk for getting it again during a future pregnancy and for developing diabetes later in life.
Gestational diabetes usually has no symptoms and that’s why almost all pregnant women have a glucose-screening test between 24 and 28 weeks. However, if you’re at high risk for diabetes or are showing signs of it (such as having sugar in your urine), your caregiver will recommend this screening test at your first prenatal visit and then repeat the test again at 24 to 28 weeks if the initial result is negative.
By the way, if you get a positive result on a glucose-screening test, it doesn’t necessarily mean that you have gestational diabetes. It does mean that you’ll need to take a longer follow-up test (a glucose tolerance test, or GTT) to find out. You are may be at an increased risk of gestational diabetes if;
- You’re obese (your body mass index is over 30).
- You’ve had gestational diabetes in a previous pregnancy.
- You have sugar in your urine.
- You have a family history of diabetes.
Some practitioners will also screen you early if you have other risk factors, such as:
- You’ve previously given birth to a big baby. Some use 8 pounds, 13 ounces (4,000 grams, or 4 kilos) as the cutoff; others use 9 pounds, 14 ounces (4,500 grams, or 4.5 kilos).
- You’ve had an unexplained stillbirth.
- You’ve had a baby with a birth defect.
- You have high blood pressure.
- You’re over 35.
Most women who develop diabetes during pregnancy go on to have healthy babies. Dietary changes and exercise may be enough to keep your blood sugar levels under control, though sometimes medication is needed, too. It’s important to keep your blood sugar levels in check because poorly controlled diabetes can have serious short- and long-term consequences for you and your baby.
If your blood sugar levels are too high, too much glucose will end up in your baby’s blood. When that happens, your baby’s pancreas needs to produce more insulin to process the extra glucose. All this excess blood sugar and insulin can cause your baby to put on extra weight, particularly in the upper body. This can lead to what’s called macrosomia. A macrosomic baby may be too large to enter the birth canal. Or the baby’s head may enter the canal but then his shoulders may get stuck. In this situation, called shoulder dystocia, your practitioner will have to use special maneuvers to deliver your baby.
Delivery can sometimes result in a fractured bone or nerve damage, both of which heal without permanent problems in nearly 99 percent of babies, (In very rare cases, the baby may suffer brain damage from lack of oxygen during this process). What’s more, the maneuvers needed to deliver a broad-shouldered baby can lead to injuries to the vaginal area or require a large episiotomy for you.
Due to these risks, if your practitioner suspects that your baby may be overly large, she may recommend that you give birth by cesarean section. In addition, babies who have excessive fat stores as a result of high maternal sugar levels during pregnancy often continue to be overweight in childhood and adulthood.
Shortly after birth, your baby may have low blood sugar (hypoglycemia) because his body will still be producing extra insulin in response to your excess glucose. This is much more likely if your blood sugar levels were high during pregnancy and especially during labor. Your delivery team will test your baby’s blood sugar at birth and continue to check it as needed by taking a drop of blood from his heel.
Feeding your baby as soon as possible after birth, preferably by breastfeeding, can help prevent or correct hypoglycemia. In severe cases of hypoglycemia, though, he’ll be given an IV glucose solution. Testing your baby’s blood sugar and providing an IV if necessary can prevent serious problems such as seizures, coma, and brain damage that might result if the condition were to go unnoticed.
Your baby may also be at higher risk for breathing problems at birth, particularly if your blood sugar levels aren’t well controlled or you deliver early (the lungs of babies whose mothers have diabetes tend to mature a bit later). The risk of newborn jaundice is increased, too.
If your blood sugar control is especially poor, your baby is at risk for polycythemia (an increase in the number of red cells in the blood) and hypocalcemia (low calcium in the blood), and your baby’s heart function could be affected as well. Some studies have found a link between severe gestational diabetes and an increased risk of stillbirth in the last two months of pregnancy.
And, finally, women with gestational diabetes are at increased risk for developing pre-eclampsia, particularly those who are obese before pregnancy or whose blood sugar levels are not well controlled.
If possible, seek health care early — when you first think about trying to get pregnant — so your doctor can evaluate your risk of gestational diabetes as part of your overall childbearing wellness plan. Once you’re pregnant, your doctor will address gestational diabetes as part of your prenatal care. If you develop gestational diabetes, you may need more-frequent checkups. These are most likely to occur during the last three months of pregnancy, when your doctor will monitor your blood sugar level and your baby’s health.
It’s stressful to know you have a condition that can affect your unborn baby’s health. However the steps that will help control your blood sugar level — such as eating healthy foods and exercising regularly — can help relieve stress and nourish your baby and help prevent type2 diabetes in the future. That makes exercise and good nutrition powerful tools for a healthy pregnancy as well as a healthy life — for you and your baby.
You’ll probably feel better if you learn as much as you can about gestational diabetes. Talk to your health care team. Read books and articles about gestational diabetes. The more you know, the more in control you’ll feel.