Gestational Diabetes and Glucose Tolerance Testing Options
What is Gestational Diabetes?
Gestational Diabetes Mellitus (GDM) is a type of diabetes that occurs specifically in pregnancy, affecting up to 10% of pregnancies in the United States.
During pregnancy, the placenta supports the baby as it grows and produces a variety of hormones to maintain the pregnancy.
The problem is, these hormones also have a habit of blocking insulin which usually begins about 20-24 weeks of pregnancy. As the placenta grows, these hormones increase and the risks of insulin resistance become greater.
Normally the pancreas is able to keep up production to overcome insulin resistance. However when the production of insulin is not enough to overcome the effect of the insulin blocking hormones, gestational diabetes results.
This causes baby’s pancreas to also produce excessive insulin in an attempt to get rid of the blood glucose. Since the baby is getting more energy than it needs to grow, the extra energy is stored as fat. This process can cause your baby to grow excessively large, also called macrosomia. Babies with macrosomia face health challenges of their own, including shoulder dystocia at birth. The extra insulin made by the baby may also cause them to have very low blood sugar at birth called hypoglycemia. Premature birth, Respiratory Distress and Stillbirth are also linked to uncontrolled GDM.
Children who are born to mothers who had uncontrolled gestational diabetes face a six-fold higher risk of developing type 2 diabetes by the time they turn 13.
How do you test for Gestational Diabetes?
Because of the insulin resistance-like effect of pregnancy hormones, it is recommended that pregnant woman are screened for Gestational Diabetes between 24-28 weeks. If you have a history of gestational diabetes, family history of diabetes, your BMI is above 30 or you had an elevated A1c with your intake labs we will recommend your test between 24-26 weeks.
There are a few different testing options. We want you to review your options below and decide which you would like to do.
1 hour GTT screening. This screens for GDM but is not diagnostic. You will take a 50g of glucola home with you and drink it (within 5 minutes) before coming to your appointment. We will draw blood from you 1 hour after drinking it. There is no need for an overnight fast with this screening but we do recommend drinking the glucola 2 hours after eating, so your glucose levels are not elevated from eating. About 15-25% of people do not pass this screening. If you do not pass this screening the recommendation is a 3 hour glucose tolerance test. This involves a fasting glucose blood draw in the morning, drink 100g glucola in 5 minutes and another blood glucose draw after an hour. Followed by 2 more draws each hour after, for a total of 4 blood draws.
2 hour diagnostic GTT. This means if you do not pass this test you have gestational diabetes. You’ll come in the morning and do a fasting glucose blood draw (no eating after midnight the night before - water only) and drink 75g of glucola in 5 minutes. We will do a glucose blood draw 1 hour after you have finished your glucola drink and 1 additional glucose draw 2 hours after you finished your glucola drink.
At home testing. You will need a glucometer with lancets and test strips which can be found easily online or aver the counter at pharmacy/drug stores. You will use this log to track your blood sugars and send to us in your portal once completed. For 7 days you will check your blood sugar in the morning when you wake up, then 1 hour after each meal. You will repeat this again at 32 weeks for another 7 days. 80% of blood sugars must be in range to pass. This is a great way to see how your body reacts to certain foods.
For those interested in another option besides glucola you can use The Fresh Test which can also be found on Amazon.
How is Gestational Diabetes Treated?
If you are diagnosed with Gestational Diabetes, the first step for management involves keeping a diet log and tracking your blood glucose levels at home. Working with your midwives and/or a nutritionist, you will begin adjusting your diet to keep your glucose levels within a specific range of normal.
You will continue at home blood glucose monitoring throughout your pregnancy. There is a possibility you may require medication to help manage your glucose levels and minimize risks to you and your baby. Most recent studies show that an estimated 15% of all Gestational Diabetic women will require medication to manage levels. In addition to dietary and lifestyle changes, you may also have co-care visits with a OB or Maternal Fetal Medicine specialist who will preform sonograms throughout the third trimester to ensure that baby is doing well.
Does Gestational Diabetes risk me out of Midwifery Care?
The good news about the above statistic is that 85% of women will be able to manage their GDM diagnosis through dietary and lifestyle changes!
In the state of Texas, as long as your glucose levels can be controlled without the use of insulin - you can continue with your out of hospital birth plans. If your status changes, or a new risk factor is discovered during your follow up scans, a hospital birth may be necessary, your midwives will work with you to transition to this new plan of care.
Am I still at risk if I test negative on my glucose screen?
While testing negative is a good sign, it is important to remember that insulin resistance is still a player throughout pregnancy for every woman.
In our practice, if you barely pass your glucose test we recommend completing a 7 day diet log and at home blood glucose monitoring in addition to beginning the supplement called Myo-Inositol. This can help you discover how your body is reacting to certain foods and alert you to any potential triggers while Myo-Inositol helps improve your insulin resistance.
Common Misconceptions
We occasionally have clients who would like to opt out of this test because they do not have any risk factors and report they eat well.
While limiting your risk factors does improve your chances of testing negative, it is important to remember that 100% of pregnant women are dealing with some form of insulin resistance because of the hormones produced by the placenta.
