The World Health Organization refers to maternal health as the health of persons during pregnancy, childbirth, and the postnatal period. Ensuring maternal health and well-being is important, and pregnancy is a time where most persons will be invested in their own self-care because of implicit benefits to the fetus. However, pregnancy is a significant life change, and coupled with a diagnosis of gestational or pregestational diabetes, a pregnant person may experience a rollercoaster of physical and emotional changes. Providing collaborative care, support, and understanding should be a focal point soon after gestational diabetes (GDM) is diagnosed or pregnancy is confirmed in a person with pregestational diabetes.
Diabetes self-care behaviors provide a strong framework to support a healthy pregnancy and should be used as tools by the diabetes care and education specialist (DCES) to assist with selfmanagement skills for persons with diabetes in pregnancy.
It is important to understand the differences between pregestational diabetes and GDM. As the name suggests, GDM is diabetes diagnosed during pregnancy and per the 2017 World Journal of Diabetes, defined as “any degree of hyperglycemia recognized for the first-time during pregnancy.” Typically, most persons without a significant history are screened between 24 and 28 weeks of gestation. Persons may be screened earlier depending on known risk factors, such as prior history of GDM, polycystic ovarian syndrome, or history of macrosomia (ie, large birth weight baby; ≥4000 g). Table 1 lists these risk factors. The American College of Obstetricians and Gynecologists (ACOG) suggests the 2-step approach for GDM screening. This involves a 50-g 1 hour glucose test administered in the nonfasting state followed by a 100-g 3-hour glucose tolerance test if positive. A diagnosis of GDM is based on 2 values equal to or more than the cutoff. See Table 2 for the 2-step approach and diagnostic criteria. Table 3 outlines the 75-g 2-hour glucose test diagnostic criteria that is administered in some situations, depending on the community the practice serves.
Pregestational diabetes is diabetes, either type 1 diabetes or type 2 diabetes, that is present prior to pregnancy. It is suggested that preconception counseling should be part of routine diabetes care starting at puberty for all persons with diabetes who have the potential for childbearing, especially given that 41% of pregnancies in the United States are unplanned. In the pregestational diabetes population and the prediabetes population, it is suggested that preconception counseling should aim for A1C levels of <6.5% if this can be safely achieved without the risk of hypoglycemia. Preconception education should include a comprehensive nutrition assessment, lifestyle recommendations, and diabetes self-management education.
As per the Centers for Disease Control and Prevention, in the United States, about 5% to 9% of people develop GDM, and 1% to 2% have pregestational diabetes.
During pregnancy, there is an ongoing supply of glucose to the fetus from the mother that is the fetus’s main source of nutrition. It is crucial to recognize that pregnancy is an insulin-resistant and ketogenic state. This is characterized by an increase in human placenta lactogen, progesterone, prolactin, placental growth hormone, and cortisol. As pregnancy progresses, insulin resistance increases typically around 16 weeks of gestation and continues until around 36 weeks of gestation.
In persons without diabetes, insulin production is sufficient to combat the increasing insulin resistance. However, in persons with pregestational diabetes and GDM, if not met, insulin requirements can result in hyperglycemia that has maternal and fetal implications. It is important to counsel this population on the implications of hyperglycemia and extremes in glucose variability. Suboptimal or poorly managed diabetes in pregnancy can result in birth defects, high blood pressure, and risk of preeclampsia, hydramnios, macrosomia, neonatal hypoglycemia, and stillbirth. It can also lead to an increased risk of developing obesity, hypertension, and type 2 diabetes for the offspring later in life. In pregestational diabetes, the risk of anomaly is related directly to the A1C value within the first 10 weeks of conception.
The DCES plays an important role in providing diabetes self-management education in this population. Counseling should include discussion on glycemic targets in pregnancy, lifestyle, and behavioral management with an emphasis on medical nutrition therapy. In both GDM and pregestational diabetes, insulin is the preferred medication for management.
In the late end of the first trimester, increased estrogen levels can increase insulin sensitivity and thereby maternal hypoglycemia. This contrasts with the increasing insulin resistance as pregnancy progresses. Hence, it highlights the need for ongoing glycemic management throughout pregnancy in a person with pregestational diabetes or GDM. Both ACOG and the ADA recommend that persons with GDM and pregestational diabetes self-monitor blood glucose at least 4 times a day. This includes a fasting glucose level and a 1-hour or 2-hour postprandial glucose check. Table 4 lists these targets for persons with GDM and pregestational diabetes. In some cases, where glycemic management is challenging and for those with pregestational diabetes, self-monitoring is useful if it can include premeal checks as well. A1C levels are not routinely monitored in pregnancy because the physiological increase in red blood cell turnover during this period can falsely lower A1C. As an average measure of glycemia, it can also miss the variability and postprandial hyperglycemia that may occur in pregnancy. Although fructosamine may offer some benefit, this is not routinely drawn in persons with pregestational diabetes or GDM and is not able to predict fasting or postprandial hyperglycemia, both of which are associated with maternal and fetal outcomes.
Continuous glucose monitoring (CGM) is a useful tool to track trends and provide insights in for Persons With Gestational and Pregestational Diabetes glycemic variability. The CONCEPTT (Continuous Glucose Monitoring in Women with Type 1 Diabetes in Pregnancy Trial) trial demonstrated that the use of real-time CGM in pregnancy for persons with type 1 diabetes had positive outcomes for decreased large for gestational age births, severe neonatal hypoglycemia, and length of infant hospital stays. It improved maternal time in range without an increase in hypoglycemia. CGM offers many benefits and is being used much more frequently in persons with GDM and type 2 diabetes. The use of CGM provides an overall view of glycemic trends and may be especially helpful when used to safely adjust insulin in this population. It is beneficial to individualize use of CGM based on factors such as treatment regimens, preferences, and circumstances. The ADA Standards of Care recommend that CGM should be used as an adjunct to self-monitoring blood glucose. The FDA has approved DEXCOM G7 and both Freestyle Libre 2 and Freestyle Libre 3 for use in pregnancy. Targets set by the International Consensus on Time in Range (TIR) has suggested target ranges for persons with type 1 diabetes in pregnancy. These are listed in Table 5, but they do not endorse a particular type of device or its accuracy or need for alerts and alarms. For the person with pregestational diabetes, who may be used to different glycemic targets when nonpregnant, counseling about these changes must be established, ideally in the preconception period if possible.
Medical nutrition therapy should be the cornerstone of counseling in pregnancy. Many times, there is a tendency to decrease carbohydrates to achieve euglycemia. Urine ketone testing may be helpful to prevent extremes in meal planning and starvation ketosis. Diabetes-related ketoacidosis can pose a risk for persons with type 1 diabetes and for some persons with type 2 diabetes and GDM. This can present at lower glycemic values in pregnancy and have serious consequences for the mother and fetus. Counseling should be provided to promote appropriate weight gain and a nutrient-dense meal plan. Table 6 outlines weight recommendations per trimester as per the 2020-2025 Dietary Guidelines for Americans. The guidelines recommend energy requirements stay the same as for the nonpregnant person in the first trimester, with an additional 340 Kcals in the second trimester and 452 Kcals in the third trimester. The guidelines for weight gain and caloric recommendations have remained unchanged. An RDN well versed with diabetes in pregnancy can help the person aim for balanced meals with complex carbohydrate choices, a combination of polyunsaturated and monounsaturated fats, and protein. In pregnancy, the carbohydrate recommendation is 175 g per day, at least 71 g of protein and 28 g of fiber. Vitamin supplementation with at least 400 μg of folic acid is recommended preconception, and this is increased to 600 μg in pregnancy. The ADA offers sample meal plans and menu ideas that may be helpful as a guide to the DCES working with this population. See the resource section for a link.
Barring any medical restrictions, persons with diabetes in pregnancy should be encouraged to include daily physical activity. As per ACOG, pregnant persons should ideally aim for at least 150 minutes of moderate intensity physical activity per week. For persons with type 1 diabetes and type 2 diabetes or GDM on insulin, safety precautions to prevent and treat hypoglycemia should be discussed. It is important to recognize that hypoglycemia in pregnancy is blood glucose values of ≤60 mg/dL. Fast-acting glucose source and/or glucagon prescriptions should be discussed and provided to these persons.
As per ACOG, depression occurs in 1 of 10 persons in pregnancy, and anxiety is also common. For the person with diabetes, enjoying the pregnancy may sometimes be challenging, especially with the expectations regarding glycemic management. Referral to a mental health specialist should be considered if this affects activities of daily living. The DCES can play a role in promoting mental health by providing tools for healthy coping.
In many cases, despite lifestyle management, hyperglycemia may persist because of increasing insulin resistance as pregnancy progresses. If fasting or postprandial hyperglycemia persists, medication intervention must be considered because there are multiple maternal and fetal risks associated with hyperglycemia. Insulin is considered the “gold standard” for treatment of both GDM and pregestational diabetes. We know that persons with type 1 diabetes always need insulin; however, insulin is preferred for both GDM and type 2 diabetes as well. Insulin does not cross the placenta and is used to lower the mother’s blood glucose, which in turn prevents high blood glucose going across to the fetus. For persons with GDM, intermediate acting insulin is typically prescribed to help with fasting hyperglycemia, and bolus insulin may be needed as well. For persons with type 2 diabetes, basal bolus therapy may be the preferred course of therapy. Insulin does need frequent titration because of changing needs throughout pregnancy, and a frank discussion regarding these expectations should be had with the person to better prepare them for the change. In some cases, insulin pump therapy may be an option; however, as with any therapeutic intervention, there should be a person-centered discussion for best route of medication.
Both metformin and glyburide cross the placenta, and studies have linked glyburide in pregnancy with a higher risk of neonatal hypoglycemia and increased neonatal abdominal circumference. It is recommended that metformin be discontinued prior to the end of the first trimester if it was taken to treat polycystic ovarian syndrome. Oral medication with these classes of drugs should be considered only if there are barriers to insulin and only after discussing the risk profile of these medications with the pregnant person.
The first 12 weeks after delivery, also referred to as the fourth trimester, is a critical period for maternal health. During this time, there is a shift from the mother to the newborn and can often result in gaps in care for the mother. Diabetes in pregnancy for both GDM and pregestational diabetes can be markers for cardiometabolic risks. For the person with pregestational diabetes, it is important to ensure smooth transitions of care after delivery. For these persons, a postpartum plan must be in place, ideally in the third trimester, to adjust for the decreased insulin needs, which may be even lower than prepregnancy needs. For persons with GDM, a postpartum screen between 4 and 12 weeks is recommended to rule out prediabetes and diabetes.
Breastfeeding has many benefits, including decreasing the risk of type 2 diabetes for both the mother and the offspring, and should be encouraged with appropriate resources. Referral to a lactation consultation and collaboration with service providers to increase breastfeeding is recommended.
Diabetes in pregnancy can be daunting, with a seesaw of emotional and physical changes. The DCES can be a font of knowledge and support during this time. By participating in shared decision-making and providing positive reinforcement, the DCES can support the person during the pregnancy. Utilizing the ADCES7 Self- Care Behaviors as the framework, the DCES can empower the person to navigate the pregnancy journey with confidence and care.
Alefiya Faizullabhoy, MBA, MS, RD, CDCES, CDN, FAND works with Northwell Health, in New Hyde Park, NY.
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