Gestational diabetes is a type of diabetes that occurs in non-diabetic women during pregnancy. Diabetes is a disease in which the pancreas is unable to produce insulin or use the insulin it produces in the proper way. Gestational diabetes affects about 3 to 6 percent of all pregnant women. It usually begins in the fifth or sixth month of pregnancy (weeks 24 and 28) and usually disappears shortly after delivery.
After a meal, a portion of the food a person eats is broken down into sugar (glucose). The sugar then passes into the bloodstream and the cells via a hormone called insulin, produced by the pancreas.
Normally, the pancreas produces the right amount of insulin to accommodate the quantity of sugar. However, if the person has diabetes, either the pancreas produces little or no insulin, or the cells do not respond normally to the insulin.
In gestational diabetes, the woman is producing the right amount of insulin, however, the effect of insulin is partially blocked by a variety of other hormones (such as progesterone, prolactin, estrogen, cortisol and human placental lactogen) made in the placenta (the organ that provides nourishment to the baby while developing inside the mother). This process is called insulin resistance, and begins about 20 to 28 weeks into pregnancy. As the placenta grows, more of these hormones are produced and the greater the insulin resistance becomes. In most women, the pancreas is able to make additional insulin to overcome insulin resistance. When the pancreas makes all the insulin it can and there still is not enough to overcome the effect of these hormones, gestational diabetes results.
Any woman can develop gestational diabetes during pregnancy, however, there are certain factors that put a woman more "at risk" for developing gestational diabetes. These risk factors include:
- over the age of 30
- family history of diabetes
- having previously given birth to a very large child (over 9 pounds, 14 ounces), having previously given birth to a stillborn child or a child with a birth defect
- having too much amniotic fluid
- having gestational diabetes in a previous pregnancy
- having high blood pressure
Generally, gestational diabetes may not cause any symptoms, however, the woman may experience excessive weight gain, excessive hunger or thirst, excessive urination or recurrent vaginal infections.
Gestational diabetes is detected through a glucose tolerance test, taken from week 24 through week 28 of pregnancy. If the woman is considered at risk for developing gestational diabetes, the doctor may test the woman as early as 13 weeks into the pregnancy.
The glucose (blood sugar) tolerance test involves drinking a glucose (sugar) solution. After waiting one hour, blood is taken from a vein in the arm and the glucose level is checked. A woman with a glucose level of less than 140 mg/dl is presumed not to have gestational diabetes and no further testing is done.
If the glucose level is above 140 mg/dl, a three-hour glucose tolerance test will be performed. The three-hour glucose tolerance test involves eating a diet of at least 150 grams of carbohydrates each day, three (3) days prior to the test. Ten to 14 hours before the test, the woman should not eat or drink anything but water. The test is administered in the doctor's office in the morning and begins with the doctor taking a blood sample. This blood sample is used to determine the fasting glucose level. The woman will then drink a glucose solution and blood will be drawn every hour for three hours after the drink has been consumed. The results of the tests will be compared to the "normal" values. If two or more of the glucose levels are higher than the normal values, a diagnosis of gestational diabetes can be made.
Treatment for gestational diabetes includes eating a carefully planned diet, getting plenty of exercise, maintaining a healthy pregnancy weight, monitoring glucose levels and, if necessary, daily insulin injections.
To help the blood sugar level to stay within a normal range (60 to 120 mg/dl):
- Avoid sugar and foods high in sugar.
- Eat complex carbohydrates such as pasta, rice, grains, cereals, crackers, bread, potatoes, dried beans and peas.
- Eat fiber-rich foods such as whole grain cereals and breads, fruits and vegetables.
- Avoid saturated fats such as fatty meats, butter, bacon, cream and whole milk cheeses.
- Eat a snack before bedtime that is protein and carbohydrate based.
The doctor will help in determining a diet plan that fits the woman's needs.
Talk with the doctor about what exercise program is right for the woman. According to the American College of Obstetricians and Gynecologists, women are encouraged to exercise at least three or four days a week, with each session lasting 15 to 30 minutes. Women should avoid very strenuous activity and should not become overheated. If the woman has not exercised prior to pregnancy, a gradual introduction to exercise is recommended. Talk with your doctor regarding individual exercise needs and limitations.
Maintain a healthy pregnancy weight
Optimal weight gain depends on the pre-pregnancy weight of the woman. If the woman is at a desirable weight for her body size and height, a weight gain of 25 to 35 pounds is recommended. If the woman is 20 pounds or more above the desired weight, a weight gain of 20 to 24 pounds is recommended. If the woman is underweight, a weight gain of 28 to 36 pounds is recommended. This is dependent on how underweight the woman is pre-pregnancy. Talk with the doctor about his or her views on how much the woman should gain during the entire pregnancy.
Monitor glucose levels
Depending on the severity of the gestational diabetes, the doctor may want a daily or weekly glucose level test performed. There are self-blood glucose monitoring tests available that can be administered at home. These tests are done by using a special device to obtain a drop of blood and test for the blood sugar level.
Daily insulin injections
Insulin injections may be necessary if the dietary changes and exercising does not bring the blood sugar level within normal range. When two abnormal values occur in one week, the doctor may recommend insulin. A typical regimen begins with a small dose of intermediate-acting and/or regular insulin, taken once or twice daily, with adjustments to be made as insulin resistance increases. The doctor will explain the different kinds of insulin, the right amount of insulin to take and when to take it, and how to change the dosage.
- Ultrasound is used to determine the position and the size of the baby.
- Fetal movement records involve the woman recording the number of times a baby kicks or moves within a two-hour period.
- Fetal monitoring involves measuring the baby's heart rate, and the strength and frequency of contractions at the same time.
During fetal monitoring, the doctor can also do a non-stress test on the baby. By rubbing the mother's stomach or introducing loud noises, the baby's movements and heart rate are measured. If the heart rate goes up, the test is normal. If the heart rate does not accelerate when the baby is externally stimulated, the doctor will do a stress test.
During the stress test, the mother is given a hormone (called oxytocin) which stimulates internal uterine contractions. During a contraction, the baby is momentarily deprived of its blood supply and oxygen, which forces the baby to respond with a higher heart rate. If the baby's heart rate slows down rather than speeds up, the baby may be in jeopardy.
Complications of Gestational Diabetes
If untreated or poorly controlled, gestational diabetes can cause the baby to:
- have macrosomia (excessive weight at birth exceeding 9 pounds, 14 ounces)
- develop hypoglycemia (low blood sugar) at birth
- develop jaundice (yellow skin)
- develop respiratory distress syndrome (breathing difficulties)
- die after week 28 of pregnancy (called a stillbirth)
- die in infancy
Gestational diabetes usually goes away after pregnancy, but, once a woman has had gestational diabetes, the chances are 75 percent that it will return in future pregnancies. In a few women, however, pregnancy uncovers insulin-dependent (Type I) or non-insulin dependent (Type II) diabetes. In other women, gestational diabetes increases their chances of developing Type II diabetes within eight years.
What tests are used to diagnose gestational diabetes?
Can diet correct or prevent gestational diabetes?
What kind of diet plan should be followed and how rigid is it?
Will insulin injections be needed?
Will diabetes harm the development of the fetus?
Could the baby become a diabetic later on?
What are the chances of remaining a diabetic after delivery or becoming a diabetic later?