Diabetes in Pregnancy

• The American Diabetes Association (ADA) "Standards of Medical Care in Diabetes" contains ADA's current clinical practice recommendations.
• It provides the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care.
• The ADA Professional Practice Committee updates the standards annually or more frequently if needed.

Diabetes in Pregnancy

• The prevalence of diabetes in pregnancy is increasing in the U.S., along with the worldwide obesity epidemic.
• Increasing rates of both type 1 and type 2 diabetes in women of reproductive age, as well as gestational diabetes mellitus (GDM) are being seen.
• Diabetes increases maternal and fetal risks.
• Degree of hyperglycemia, chronic complications, and co-morbidities all related to diabetes are key factors.
• Specific risks include spontaneous abortion, fetal anomalies, preeclampsia, fetal demise, macrosomia, neonatal hypoglycemia, hyperbilirubinemia, and neonatal respiratory distress syndrome.
• Diabetes in pregnancy may increase the risk of obesity, hypertension, and type 2 diabetes in offspring later in life.

Preconception Counseling

• Preconception counseling recommendations should start at puberty and continue in all women with diabetes and reproductive potential.
• Family planning should be discussed, and effective contraception should be prescribed until a woman's treatment regimen and A1C are optimized for pregnancy
• Preconception counseling should emphasize glucose levels as close to normal as safely possible, ideally A1C <6.5% (48 mmol/mol).
• This reduces risk of congenital anomalies, preeclampsia, macrosomia, preterm birth, and other complications.
• All women of childbearing age with diabetes should be informed about achieving and maintaining euglycemia prior to conception and throughout pregnancy.
• Observational studies reveal an increased risk of diabetic embryopathy.
• Especially anencephaly, microcephaly, congenital heart disease, renal anomalies, and caudal regression, directly proportional to elevations in A1C during the first 10 weeks is a factor.
• Lower A1C is associate with reduced risk of birth defects, preterm delivery, perinatal mortality, small-for-gestational-age births, and neonatal intensive care unit admission.
• Education is vital for all women and adolescents of reproductive age with diabetes regarding the risks of unplanned pregnancies and improved outcomes with pregnancy planning.
• Preconception counseling can significantly reduce health issues in offspring.
• Family planning should be discussed, including long-acting, reversible contraception.
• Effective contraception should be used until a woman is prepared to become pregnant.
• Education should focus on the risks of malformations associated with unplanned pregnancies and the importance of effective contraception at all times when preventing pregnancy.
• American Diabetes Association (ADA) provides preconception counseling resources tailored for adolescents at no cost (16).

Preconception Care Recommendations

• Women with preexisting diabetes who are planning a pregnancy should ideally be managed beginning in preconception in a multidisciplinary clinic.
• Including an endocrinologist, maternal-fetal medicine specialist, registered dietitian nutritionist, and diabetes care and education specialist, when available
• There should be focused attention on achieving glycemic targets.
• Standard preconception care should be augmented with extra focus on nutrition, diabetes education, and screening for diabetes comorbidities and complications.
• Women with preexisting type 1 or type 2 diabetes who are planning pregnancy or who have become pregnant should be counseled on the risk of development and/or progression of diabetic retinopathy.
• Dilated eye examinations should occur ideally before pregnancy or in the first trimester.
• Patients should be monitored every trimester and for 1 year postpartum as indicated by the degree of retinopathy and as recommended by the eye care provider.
• Key is presence of questions about a woman's plans for pregnancy into routine primary and gynecologic care.
• Preconception care should include standard screenings and care for all women planning pregnancy, including prenatal vitamins (with folic acid and potassium iodide).
• Review and counseling on nicotine products, alcohol, and recreational drugs includes marijuana, and is important.
• Standard care includes screening for sexually transmitted diseases and thyroid disease, vaccinations, routine genetic screening, medication reviews, and a review of travel history.
• Diabetes-specific counseling should include explanation of the risks to mother and fetus related to pregnancy and the ways to reduce risk, including glycemic goal setting, lifestyle and behavioral management, and medical nutrition therapy.
• Diabetes-specific testing should include A1C, creatinine, and urinary albumin-to-creatinine ratio.
• Special attention should be paid to reviewing medication list for ACE inhibitors, angiotensin receptor blockers and statins.
• A referral for a comprehensive eye exam is recommended.
• Women with preexisting diabetic retinopathy will need close monitoring during pregnancy to assess for progression of retinopathy and provide treatment if indicated (24).
• Several studies have shown improved diabetes and pregnancy outcomes when care has been delivered from preconception through pregnancy by a multidisciplinary group focused on improved glycemic control.

Glycemic Targets in Pregnancy

• Fasting and postprandial self-monitoring of blood glucose are recommended in both gestational diabetes mellitus and preexisting diabetes in pregnancy to achieve optimal glucose levels.
• Glucose targets are fasting plasma glucose <95 mg/dL (5.3 mmol/L) and either 1-h postprandial glucose <140 mg/dL (7.8 mmol/L) or 2-h postprandial glucose <120 mg/dL (6.7 mmol/L).
• Some women with preexisting diabetes should also test blood glucose pre-prandially.
• Due to increased red blood cell turnover, A1C is slightly lower in normal pregnancy than in normal nonpregnant women.
• Ideally, the A1C target in pregnancy is <6% (42 mmol/mol) if this can be achieved without significant hypoglycemia.
• The target may be relaxed to <7% (53 mmol/mol) if necessary to prevent hypoglycemia.
• Continuous glucose monitoring can help to achieve A1C targets in diabetes and pregnancy in addition to pre- and postprandial blood glucose monitoring
• Real-time continuous glucose monitoring can reduce macrosomia and neonatal hypoglycemia in pregnancy complicated by type 1 diabetes when used in addition to blood glucose monitoring targeting traditional pre- and postprandial targets.
• Continuous glucose monitoring metrics may be used in addition to but should not be used as a substitute for self-monitoring of blood glucose to achieve optimal pre- and postprandial glycemic targets
• Commonly used estimated A1C and glucose management indicator calculations should not be used in pregnancy as estimates of A1C.

Insulin Physiology

• Pregnancy in women with normal glucose metabolism is characterized by lower fasting blood glucose levels due to insulin-independent glucose uptake by the fetus and placenta.
• Mild postprandial hyperglycemia and carbohydrate intolerance is a result of diabetogenic placental hormones.
• In patients with preexisting diabetes, glycemic targets are achieved through insulin and medical nutrition therapy.
• Women with diabetes should eat consistent amounts of carbohydrates to match with insulin dosage because pregnancy glycemic targets are stricter.
• Referral to an RD/RDN is important to establish a food plan and insulin-to-carbohydrate ratio and to determine weight gain goals.
• Early pregnancy is a time of enhanced insulin sensitivity and lower glucose levels.
• Many women with type 1 diabetes will have lower insulin requirements and an increased risk for hypoglycemia
• Insulin resistance begins to increase around 16 weeks, and total daily insulin doses increase linearly ~5% per week through week 36.
• There will be a doubling of daily insulin dose compared with the pre-pregnancy requirement.
• The insulin requirement levels off toward the end of the third trimester with placental aging. A rapid reduction in insulin requirements can indicate the development of placental insufficiency
• Fasting and postprandial monitoring of blood glucose is recommended to achieve metabolic control in pregnant women with diabetes, reflecting this physiology.
• Preprandial testing is also recommended when using insulin pumps or basal-bolus therapy so that premeal rapid-acting insulin dosage can be adjusted.
• Postprandial monitoring is associated with better glycemic control and a lower risk of preeclampsia
• The ADA-recommended targets for women with type 1 or type 2 diabetes are fasting glucose 70-95 mg/dL (3.9-5.3 mmol/L) and either , One-hour postprandial glucose 110-140 mg/dL (6.1-7.8 mmol/L) or Two-hour postprandial glucose 100-120 mg/dL (5.6-6.7 mmol/L).
• Lower limits are based on the mean of normal blood glucose in pregnancy. Lower limits do not apply to diet-controlled type 2 diabetes. Hypoglycemia in pregnancy is as defined and treated in Recommendations 6.9-6.14
• Studies of women without preexisting diabetes, increasing A1C levels within the normal range are associated with adverse outcomes

Management of Gestational Diabetes Mellitus

• Lifestyle behavior change is an essential component of managing gestational diabetes mellitus and many women may only require that.
• Insulin should be added if needed to achieve glycemic targets.
• Insulin is the preferred medication for treating hyperglycemia in gestational diabetes mellitus.
• Metformin and glyburide should not be used as first-line agents, as both cross the placenta to the fetus.
• Metformin, when used to treat polycystic ovary syndrome and induce ovulation, should be discontinued by the end of the first trimester.
• GDM is characterized by increased risk of large-for-gestational-age birth weight and neonatal and pregnancy complications
• There is increased risk of maternal type 2 diabetes and offspring abnormal glucose metabolism in childhood.
• Short-term and long-term risks increase with progressive maternal hyperglycemia. Therefore, all women should be screened.
• Treatment starts with medical nutrition therapy, physical activity, and weight management.

Postpartum Care

• Insulin resistance decreases dramatically immediately postpartum, and insulin requirements need to be evaluated and adjusted as they are often roughly half the prepregnancy requirements for the initial few days postpartum.
• A contraceptive plan should be discussed and implemented with all women with diabetes of reproductive potential.
• Women with a recent history of gestational diabetes mellitus need tested at 4-12 weeks postpartum, using the 75-g oral glucose tolerance test.
• Women with a history of gestational diabetes mellitus found to have prediabetes should receive intensive lifestyle interventions and/or metformin to prevent diabetes.
• Women with a history of gestational diabetes mellitus should have lifelong screening for the development of type 2 diabetes or prediabetes every 1-3 years.
• Women with a history of gestational diabetes mellitus should seek preconception screening for diabetes and preconception care to identify and treat hyperglycemia and prevent congenital malformations.
• Postpartum care should include psychosocial assessment and support for self-care.