Gestational Diabetes

Posted in Pregnancy

Diabetes is a serious disease that impairs the body’s use of glucose, taxes the pancreas, and causes long-term damage to tiny capillaries in the body. Diabetes begins when too much glucose, the energy molecule that comes from food, is present in circulation. The pancreas is required to produce insulin, the hormone that lowers blood sugar, in great quantities and in irregular spurts. Basically, this wears the pancreas out and makes the body’s cells less responsive to insulin over time. Additionally, the extra circulating glucose causes capillaries to burst, impeding blood flow and tissue repair. There are three main types of diabetes:

TYPE I DIABETES is a chronic irreversible condition in which the pancreas produces little or no insulin. It used to be known as juvenile diabetes or insulin-dependent diabetes.

TYPE II DIABETES is the most common form of diabetes and occurs when the body becomes resistant to insulin or doesn’t make enough insulin. It is largely caused by diet and lifestyle, and affects adults and children alike.

GESTATIONAL DIABETES is a term used for diabetes that is first diagnosed during pregnancy. Gestational diabetes starts when the body is not able to make and use all the insulin it needs for pregnancy. Without enough insulin, glucose cannot leave the blood and be changed to energy. Glucose builds up in the blood to high levels. This is called hyperglycemia.


Gestational diabetes affects pregnant people in late pregnancy, after the baby’s body has been formed. Because of this, gestational diabetes does not cause the kinds of birth defects sometimes seen in babies whose parents had diabetes before pregnancy. However, untreated or poorly controlled gestational diabetes can hurt babies. When a person has gestational diabetes, the pancreas must work overtime to produce insulin, but the insulin does not lower blood glucose levels. Extra blood glucose goes through the placenta, giving the baby high blood glucose levels. It is important to keep blood sugar at normal levels during pregnancy for the following reasons:

  • The baby might grow too big and experience shoulder dystocia during birth (occurs when the shoulders are too large and get stuck behind the pubic bone)
  • High blood sugar levels during pregnancy can lead to the baby’s blood sugar level dropping rapidly and significantly after birth, leading to life-threatening low blood sugar (hypoglycemia)
  • Higher chance of needing an induction or cesarean birth
  • Higher chance of baby needing to stay in the NICU
  • Your child will face a 6-fold higher risk for diabetes and pre-diabetes in adolescence and beyond
  • You have a higher risk of developing Type II Diabetes after pregnancy


GDM is associated with certain lifestyle and genetic factors:

  • Overweight, obesity and/or high body mass index
  • Older than 25-years-old, and especially older than 45-years-old
  • Family members with diabetes, especially parents or siblings
  • GDM or a large baby in previous pregnancies
  • Member of a high-risk ethnic group, including Native American, Asian, Hispanic, and Pacific Islander

According to the American College of Obstetricians and Gynecologists (ACOG), if you do not have any of these risk factors you may not need to be screened. While you cannot change your ethnic group or family members, you can positively impact your glucose metabolism with education and changes in diet and lifestyle.


The most common method of screening for GDM in the U.S. is the 50-gram, 1-hour glucola test, also called the glucose challenge test. This test was first introduced in 1973. To take the glucola test, you eat a normal diet beforehand and then drink a 50-gram glucose polymer solution. One hour later, your blood is drawn to measure the glucose level. If your blood glucose is 140 mg/dL or higher, then you have screened positive for GDM, and you qualify for a follow-up 3-hour oral glucose tolerance test (OGTT) with a 100-gram glucose solution to officially diagnose the condition. There are alternatives to the standard 1-hour GDM screen. These include alternatives such as a 50-gram glucose meal, apple juice or jellybeans, and using a fasting glucose screen.


The potential adverse effects of the glucola test are nausea (30%), vomiting, bloating, diarrhea, dizziness (11%), headache (9%), and fatigue. Another very important aspect of the glucola test to consider is the ingredients in the drink. Most contain brominated vegetable oil (BVO), high fructose corn syrup, artificial flavors and colors, and the glucose itself is derived from GMO corn. These are all ingredients not to consume during pregnancy (if ever)!


The key to overall health and to dealing with problems in glucose metabolism is, not so surprisingly, daily intake of fresh, unprocessed whole foods and daily aerobic and weight-bearing exercise. Of course, the longer you have done these prior to pregnancy the better your general health will be. During pregnancy, your care provider will discuss how a healthy, balanced diet and exercise plan, prenatal vitamins, customized herbal or nutritional supplements, and lifestyle changes can be incorporated into your pregnancy and family life. Some pregnant people will develop GDM regardless of risk factors or lifestyle choices, however. If you are diagnosed with GDM, you and your care provider will work together to come up with a personalized nutrition and exercise plan. You may be referred to dieticians and/or an OBGYN (if working with a midwife) as necessary.


American Diabetes Association: Gestational Diabetes Mellitus
Centers for Disease Control (CDC): Diabetes and Pregnancy
Evidence Based Birth: Gestational Diabetes and the Glucola Test
American College of Nurse Midwives (ACNM) Gestational Diabetes Information Sheet
Aviva Romm MD: Gestational Diabetes: Please Don’t Drink the “Glucola” Without Reading the Label


  • Decline GDM screening at 27-29 weeks of pregnancy
  • Accept GDM screening at 27-29 weeks of pregnancy using the standard 1-hour glucola test
  • Accept GDM screening at 27-29 weeks of pregnancy using alternatives to the 50-gram glucose drink, such as a 50-gram glucose meal or juice/jelly beans
  • Accept GDM screening at 27-29 weeks of pregnancy using a fasting blood glucose screen

If you choose not to screen for GDM, even in the presence of risk factors, that is your right but you would not be following the standard recommendations for achieving a healthy pregnancy outcome. Make sure you talk to your healthcare provider about GDM screening and treatment before you reach 28 weeks gestation.