What is Gestational Diabetes?
During pregnancy, hormonal changes may cause impaired glucose tolerance and higher insulin needs. If the pancreas in a pregnant woman cannot keep up with the insulin needs, the blood glucose levels will rise above desired levels. Higher than normal blood glucose levels are harmful to the woman and her fetus. About 1 in 15 women develop gestational diabetes when pregnant.
How is it Diagnosed?
Most women have an oral glucose tolerance test at week 24-28 in the pregnancy, the second trimester. A high blood glucose test earlier in the pregnancy would alert the doctor to investigate sooner. The glucose challenge screening test consists of consuming 50 of glucose and then testing blood sugars
at the beginning and at one hour. The one hour blood glucose should be less than 140 mg/dL. If higher, a glucose tolerance test may be ordered. A glucose tolerance diagnostic test for gestational diabetes consists of drinking 100g of glucose and testing blood glucose fasting and every hour for 3 hours. The trends in the rise of blood glucose define the diagnosis. If two or more of these values are exceeded in the oral glucose tolerance test
(OGTT), the diagnosis is positive. Fasting _> 95 mg/dl, 1 hour _>180 mg/dl, 2 hours _> 155 mg/dl, and 3 hours _> 140 mg/dl.
What is the Concern?
The developing baby is affected by the high blood sugars in utero. In early pregnancy, high blood sugars in the mother can cause birth defects and increased rate of miscarriages. During the second and third trimesters of the pregnancy, the mother can gain excessive weight, as well as the baby. A large baby is at increased risk during labor and delivery. The baby, which may have high blood glucose before birth, will have a severe drop in blood glucose at birth, and must be carefully managed. The baby is at increased risk of jaundice just after birth, which is treated with special lights to remove the bilirubin pigment that has collected in the blood and skin. With proper treatment, a woman with gestational diabetes can have a healthy baby. Her blood glucose levels will also return to normal after delivery. However, women with diabetes during pregnancy have a 40-60% chance of developing pre-diabetes and diabetes in the future.
Who is at Risk?
This is a list of factors that increase the risk of developing gestational diabetes for women during pregnancy:
- -Overweight prior to pregnancy (20% or more over ideal body weight)
- -High risk ethnic group: Hispanic, African American, Native American, Asian
- -Impaired glucose tolerance or traces of glucose in the urine
- -Family history of diabetes
- -Previously giving birth to a baby over 9 lbs. or stillborn
- -Previous pregnancy with gestational diabetes
How is Gestational Diabetes Treated?
The goal is to control blood glucose levels carefully, between 95 mg/dl (fasting) to 120 mg/dl two hours after a meal. To do this, the woman will need a blood glucose monitor and test her blood sugar often, a minimum of four times a day. The urine is also checked for ketones
, which means poor control if present. There are dietary changes that are designed to limit carbohydrates, but provide adequate carbohydrate, calories
and nutrients for acceptable weight gain. A registered dietitian can provide appropriate meals plans. The woman will have exercise recommendations, and her weight gain will be closely monitored. The only medication used during gestational diabetes is insulin. The pregnant woman most likely will need to control her blood glucose with insulin injections, as prescribed by her doctor.
More on the Diet
The diet will be planned as three small meals and two or three snacks. Meals and snacks should not be skipped. If on insulin, the woman is in danger of low blood sugars also, which could cause dizziness, confusion, weakness and passing out. Carbohydrates are planned to be lower than normal, 40-45 percent of total calories. These will be distributed evenly throughout the day. High fiber
foods, healthy fats
and lean proteins
are recommended. Drinking plenty of non-caloric fluids (64 oz.) a day and taking a prenatal vitamin are important habits.
Women of average weight are expected to gain 25-35 lbs during pregnancy. Your doctor might alter these recommendations depending on the beginning pregnancy weight. The rate of weight gain is very important. During the first three months, the weight gain is 2-4 lbs., then about one pound a week the rest of the pregnancy. After delivery, her blood sugar should return to normal, but will be rechecked 6-8 weeks postpartum. Maintaining an ideal body weight, healthy diet and exercise routine, the woman can reduce her risk of developing problems with blood glucose in the future. The child will also have an increase risk of diabetes
in his/her lifetime.
Reviewed by Sharon Howard, R.D., M.S., C.D.E, F.A.D.A - 02/13