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Guideline 6

Guideline 6: Perinatal Gestational Diabetes Mellitus Assessment 

Purpose 

Gestational diabetes mellitus (GDM), which the American Diabetic Association (ADA) defines as diabetes diagnosed in the second or third trimester that was not clearly overt diabetes prior to conception, is a common disorder of pregnancy. It occurs when the body becomes relatively more resistant to insulin, resulting in high blood sugar. It is estimated that 10% of pregnancies in North America are impacted by GDM. Long-term risks of GDM for the birthing parent include cardiovascular disease and type 2 diabetes; an estimated 50-60 percent of people with GDM will develop type 2 diabetes later in life.  
It is the severity of the hyperglycemia during pregnancy that is important to short- and long-term outcomes, and untreated or poorly controlled GDM can lead to many complications, including preeclampsia, preterm delivery and birth trauma. Complications for the baby may include stillbirth, macrosomia (large for gestational age at birth), neonatal hypoglycemia, and risks for future development of obesity and diabetes. For the birthing parent, GDM is also associated with an increased risk of postpartum depression, and individuals with GDM may also be at risk for delayed secretory activation and low milk supply. Skilled intervention from an IBCLC after delivery may be needed to improve breast/chestfeeding duration and exclusivity. 
Screening for, and treatment of, GDM is an important component of prenatal care, and is associated with improved outcomes, including reductions in cesarean births, birth injuries, NICU admissions and stillbirth.

Process  

  • During the initial prenatal assessment, assess for a diagnosis of GDM during the current or with any previous pregnancies, as applicable. 
  • Clients with risk factors for type 2 Diabetes (see Table 1) should be screened for diabetes at their first prenatal visit using standard diagnostic criteria. Because only about 10 percent of individuals meet all criteria for a low risk of GDM, some providers will universally screen all clients at their first prenatal visit. A diagnosis of diabetes at this time is considered overt Type I or II diabetes, not GDM. 
  • Clients not previously known to have diabetes should be screened for GDM at 24-28 weeks of gestation. 
  • GDM Diagnosis at 24-28 weeks can be accomplished by two different strategies. There is currently no consensus on which of the following is the optimal approach:  
  • One-step test: consists of only a diagnostic test, typically a fasting 75 g oral glucose tolerance test (OGTT)  
  • Two-step test: consists of a non-fasting 50 g glucose screen followed by a diagnostic fasting 100 g OGTT for those who screen positive 
  • Provide education about screening to clients, as applicable. Connect clients to resource for GDM screening, if needed. 
  • Advise client of specific risk factors for development of GDM (see Table 1). 

Table 1. Risk Factors for Gestational Diabetes Mellitus 


  • Provide education about the risks associated with GDM (see Table 2).   

Table 2. Risks Associated with Gestational Diabetes Mellitus 


  • For clients with a diagnosis of GDM, review primary care provider plan with client and encourage them to adhere to the plan. This may include a healthy diet, physical activity, glucose monitoring, referrals to specialists (e.g. dietician, diabetes educator), and possibly medication (insulin or oral medication). Pregnant individuals with gestational diabetes may also require more frequent prenatal visits or additional fetal monitoring. 
  • Advise client with a GDM diagnosis that they will need to be tested for diabetes/prediabetes at 4-12 weeks postpartum using the 75-g oral glucose tolerance test and be screened at least every 3 years for life. 
  • Provide education on prevention or delay of type 2 diabetes later in life, including the importance of breast/chestfeeding. Longer breast/chestfeeding duration has been associated with a decreased risk of developing type 2 diabetes after GDM. 
  • Educate your clients on interventions that may help them meet their feeding goals, including frequent feedings (goal is 10-12 times per 24 hrs), skin-to-skin contact, avoidance of pacifiers until breastfeeding is well-established, and immediate and frequent support from a lactation consultant (for example, at birth and at 3, 7, and 10 days postpartum). 
  • Individuals with GDM are at higher risk for postpartum depression. Ensure screening is completed per Clinical Guideline 9: Mood Disorder Screening.  
References: 
  1. Durnwald, C. Gestational diabetes mellitus: Screening, diagnosis, and prevention. In: UpToDate, Connor RF (Ed), Wolters Kluwer. (Accessed on October 10, 2024). 
  2. American Diabetes Association. 2. Classification and diagnosis of diabetes: Standards of Medical Care in Diabetes-2020. Diabetes Care 2020;43(Suppl. 1): S14-S31 
  3. https://www.cdc.gov/diabetes/about/gestational-diabetes.html, accessed on 10/10/2024. 
  4. https://www.cdc.gov/diabetes/about/gestational-diabetes-postpartum-depression.html, accessed on 10/10/2024.  
  5. Durnwald, C. Patient education: Gestational diabetes (Beyond the Basics). UpToDate, Connor RF (Ed), Wolters Kluwer. (Accessed on October 10, 2024). 
  6. Durnwald, C. Gestational diabetes mellitus: Glucose management, maternal prognosis, and follow-up. UpToDate, Connor RF (Ed), Wolters Kluwer. (Accessed on October 10, 2024). 
  7. Caughey, AB. Gestational diabetes mellitus: Obstetric issues and management.  In: UpToDate, Connor RF (Ed), Wolters Kluwer. (Accessed on October 10, 2024). 
  8. https://www.niddk.nih.gov/health-information/diabetes/overview/what-is-diabetes/gestational/after-your-baby-is-born, accessed on 10/10/2024. 
  9. Wu, JL, Pang, SQ, Jiang, XM, Zheng, QX, Han, XQ, Zhang, XY & Pan, YQ. 2021. Gestational Diabetes Mellitus and Risk of Delayed Onset of Lactogenesis: A Systematic Review and Meta-Analysis. Breastfeeding medicine: the official journal of the Academy of Breastfeeding Medicine, 16(5), 385–392.   
  10. https://diabetes.org/living-with-diabetes/life-stages/gestational-diabetes/diabetes-breastfeeding, accessed on 10/10/2024. 
  11. https://laleche.org.uk/diabetes-and-breastfeeding/, accessed on 10/30/2024. 
  12. Sexton, S. and Natale, R. 2009. Risks and benefits of pacifiers. American Family Physician 79 (8): 681-685. 
  13. https://pmc.ncbi.nlm.nih.gov/articles/PMC6274679/