Gestational diabetes mellitus (GDM) review for maternity nursing students!
Gestational diabetes is a complication of pregnancy. It affects pregnant women in about the 2nd to 3rd month of pregnancy. In this review you will learn about:
- Gestational diabetes risk factors
- Pathophysiology of GDM
- Signs and Symptoms
- Nursing Care and Treatment
Lecture on Gestational Diabetes Mellitus
Gestational Diabetes Maternity Nursing Review
What is Gestational Diabetes Mellitus (GDM)? It’s a form of diabetes that develops during pregnancy, usually during the 2nd or 3rd trimester (hence why we call it gestational). It tends to disappear after the birth of the baby.
Why it happens? Let’s talk about:
Risk Factors for “Momma”
Maternal age over 25
Overweight or obese…BMI >25 or >30
Macrosomia (fetal) previous baby was large…example: >9 lbs
A history (previous gestational diabetes diagnosis or family history of diabetes mellitus)
Pathophysiology of Gestational Diabetes
3 Key players:
- Pregnancy: specifically the hormones that support the pregnancy and baby’s growth
- Human placental lactogen (hPL), estrogen, progesterone, and cortisol
- Mom’s metabolic system changes (specifically changes to her insulin sensitivity…mom’s insulin sensitivity lowers due to the influence of the pregnancy hormones listed above)
- Baby’s growth needs
What is diabetes? There are various types of diabetes. However, all types are due to some issue with insulin. The types includes:
Type 1 Diabetes: this is autoimmune and occurs because the cells that produce insulin (beta cells in the pancrea) are destroyed and produce little to no insulin. Therefore, there is no insulin to influence the cells to take in glucose, so it hangs out in the blood (hyperglycemia) and can leak into the urine.
Type 2 Diabetes: it’s an insulin resistance issue meaning the cells are not receptive to insulin’s influence. Therefore, insulin can’t influence cells to take in glucose, which will hang out in the blood (hyperglycemia) and can leak into the urine.
Gestational Diabetes: similar to Type 2 diabetes because of insulin resistance. It tends to occur during pregnancy (2nd to 3rd trimester) and goes away after birth. *However according to the CDC.gov: “About 50% of women with gestational diabetes go on to develop type 2 diabetes”.
So, now let’s talk more about insulin:
What is insulin? It’s a hormone secreted by the pancreas (specifically by the beta cells in the pancreas) that influence cells to take glucose from the blood into the cell so it can be used as energy.
Due to all the changes that occur during pregnancy, specifically metabolic changes, the role of insulin varies throughout pregnancy depending on how far mom is along in her pregnancy, and this is majorly due to the influence of pregnancy hormones.
To understand this let’s talk about how cells have a certain “sensitivity” to insulin and how that changes throughout the pregnancy because this is how we understand gestational diabetes.
High insulin sensitivity means the cells are really receptive to insulin so glucose easily transports into the cell. This is beneficial during early pregnancy because it helps support the growth of adipose tissue (which helps mom and baby throughout the pregnancy). However, because there is the shifting of more glucose into the cell, this can cause mom some blood glucose shifts (like hypoglycemia). She may notice she feels less nauseous or weak when she has food on her stomach. Note this tends to occur during the 1st trimester.
Low insulin sensitivity (insulin resistance) means cells are not receptive to insulin so glucose does NOT easily get transported into the cell but stays in the blood. This occurs during the 2nd or 3rd trimester and the extra glucose in mom’s blood will go to the growing baby who will use it for energy. Hormones listed above cause this low insulin sensitivity.
This is a normal metabolic change. HOWEVER, in some pregnant women the pancreas’ beta cells do NOT compensate for this change in insulin sensitivity and can NOT maintain normal blood glucose levels for the mom. Therefore, the woman has HYPERglycemia (high blood glucose levels) and this can lead to complications.
Recap: What is happening in a nutshell with the development of gestational diabetes?
During the second to third trimester, as the baby is really growing (needing energy), its demand for glucose start to increase. The baby receives it glucose from mom (glucose from mom’s blood travels to the placenta, which delivers glucose via the umbilical vessels to the baby).
The placenta is smart and knows during this time the baby will need this extra glucose (not too much but just enough). Fortunately, during this time the placenta is working very well releasing hormones that will support the pregnancy and baby.
One thing these hormones do is affect insulin sensitivity in mom. The hormones actually start to decrease her cell’s sensitivity to insulin. Therefore, mom’s cells are not as receptive to taking in glucose, so more glucose stays in her blood. This is actually helpful in helping the baby meet its energy needs because this extra glucose in mom’s blood will go to the growing baby who needs it for energy.
BUT how about mom…how can she deal with all the extra glucose…we don’t want her having too much glucose, right?
Normally, the mom’s body (pancreas) can regulate and maintain normal glucose levels by altering how the pancreas’ beta cells work (their size and number increases). As a result, there is enough insulin in mom’s body to maintain a normal glucose level: proper term is euglycemia.
However, in moms who develop gestational diabetes this regulation by the mom’s body is NOT occurring correctly. This leads to more glucose hanging out in her blood and going to the baby. The insulin cells just aren’t into using the glucose because they really can’t due to the hormones affecting how insulin works.
Consequence: Mom’s experiences hyperglycemia and this leads to the complications listed below:
- cardiovascular affects to mom (her vessels can become damaged from the high glucose levels in the blood leading to: high blood pressure/preeclampsia)
- UTIs/yeast infections: remember bacteria and yeast thrive on glucose
- Type 2 diabetes after birth
- Preterm labor
- Increased risk of C-section due to a large baby for gestational age, which is hard to deliver vaginally
- Baby can have breathing difficulties (hyperglycemia can affect lung maturity…surfactant) and hypoglycemia at birth
Signs and Symptoms of Gestational Diabetes
Similar to those of hyperglycemia…remember the 3 Ps
- Polyphagia (constant hunger)
- Polydipsia (very thirsty)
- Polyuria (voiding all the time)
- Sugar in urine (why a pregnant woman’s urine is always checked at her OB visits along for protein)
(Misc: acetone breath “fruity”, dry/hot, UTIs and vaginal yeast infections)
Gestational Diabetes Nursing Interventions & Treatment
Screening: 1 hour oral glucose tolerance test at 24-28 weeks
- fasting not required for this test
- drink 50 grams of a glucose solution
- 1 hour later have blood drawn
- Glucose of >140 mg/dL abnormal result
- Will have to have the 3 hour oral glucose tolerance test to diagnose gestational diabetes
3 hour oral glucose tolerance test (administer if 1 hr ogtt abnormal)
- Patient comes back to the office on another day to have performed
- Fasting required
- Blood drawn at the following times: fasting (then will drink 100 gram glucose solution), 1, 2, and 3 hours
- Two or more abnormal results…diagnosed with gestational diabetes
- Fasting >95 mg/dL
- 1 hour >180 mg/dL
- 2 hour >155 mg/dL
- 3 hour >140 mg/dL
*Source- Perinatology.com “3 hour Oral Glucose Tolerance Test, OGTT, GTT (serum, plasma) Criteria for Gestational; Diabetes
Use diet and exercise to manage (some may need insulin or oral diabetic medications like Glyburide)
Glucose monitoring: pregnant mom will monitor her blood glucose on a daily basis
- <95 mg/dL fasting (greater than 70 mg/dL)
- <140 mg/dL 1 hour after meal
Assess urine for glucose during prenatal visits (glucose starts to leak into the urine) and assess for burning during urination (could indicate infection)
Risk Factors for Momma:
- Maternal age over 25
- Overweight or obese…BMI >25 or >30
- Macrosomia (fetal) previous baby was large… >9 lbs
- Multiple pregnancies
- A history (previous gestational diabetes diagnosis or family history of diabetes mellitus)
Blood glucose swings during and after labor: monitor blood glucose levels during and after labor
- Try to maintain euglycemia: this could help decrease the risk of baby experiencing hypoglycemia at birth
- During labor, IV regular insulin or glucose may be given to some patients to keep their glucose level within normal range
- After labor watch for hypoglycemia in both mom (sweating, cold, clammy, confused) and baby (may need glucose solution after birth)
Adverse effects of gestational diabetes: preeclampsia (htn and protein in urine), UTI, vaginal infections, risk for c-section due to large baby, respiratory distress in baby, preterm labor, hypoglycemia after birth
Blood glucose monitoring postpartum: 6-12 weeks postpartum with 2 hour oral glucose tolerance test
Educate about importance of regular testing for diabetes due to risk of type 2 diabetes
- Every 1-3 years…even if it goes away after birth because remember 50% will go on to develop Type 2 DM
Test your knowledge: Gestational Diabetes NCLEX Questions
Gestational Diabetes and Pregnancy | CDC. Retrieved 25 January 2020, from https://www.cdc.gov/pregnancy/diabetes-gestational.html
Plows, J., Stanley, J., & Vickers, M. (2018). The Pathophysiology of Gestational Diabetes Mellitus. Retrieved 1 February 2020, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6274679/
3 hour oral glucose tolerance test, ogtt, gtt (serum plasma) Criteria for Gestational Diabetes Retrieved 1 February 2020, from http://perinatology.com/Reference/Reference%20Ranges/3OGTT.htm