Endocrine and Metabolic Disorders in Pregnancy
Endocrine and Metabolic Disorders in Pregnancy
Pre-gestational Diabetes is the label sometimes given to type 1 or type 2 diabetes that existed before pregnancy.
Gestational diabetes mellitus (GDM) is any degree of glucose intolerance with the onset or first recognition occurring during pregnancy. This definition is appropriate whether or not insulin is used for treatment or the diabetes persists after pregnancy. It does not exclude the possibility that the glucose intolerance preceded the pregnancy or that medication might be required for optimal glucose control. Women experiencing gestational diabetes should be reclassified 6 weeks or more after the pregnancy ends (ADA, 2008; Moore & Catalano, 2009).
1ST TRIM-INSULIN NEEDS ARE INCREASED
During the first trimester of pregnancy the pregnant woman's metabolic status is significantly influenced by the rising levels of estrogen and progesterone. These hormones stimulate the beta cells in the pancreas to increase insulin production, which promotes increased peripheral use of glucose and decreased blood glucose, with fasting levels being reduced by approximately 10% (Fig. 29-1, A). At the same time, an increase in tissue glycogen stores and a decrease in hepatic glucose production occur, which further encourage lower fasting glucose levels. As a result of these normal metabolic changes of pregnancy, women with insulin-dependent diabetes are prone to hypoglycemia during the first trimester.
Endocrine and Metabolic Disorders
Require careful management to promote maternal and fetal well-being
Diabetes mellitus is most common endocrine disorder associated with pregnancy
Pregestational Diabetes Mellitus
Gestational Diabetes Mellitus
During the second and third trimesters, pregnancy exerts a "diabetogenic" effect on the maternal metabolic status. Because of the major hormonal changes, decreased tolerance to glucose, increased insulin resistance, decreased hepatic glycogen stores, and increased hepatic production of glucose occur. Rising levels of human chorionic somatomammotropin, estrogen, progesterone, prolactin, cortisol, and insulinase increase insulin resistance through their actions as insulin antagonists. Insulin resistance is a glucose-sparing mechanism that ensures an abundant supply of glucose for the fetus. Maternal insulin requirements gradually increase from approximately 18 to 24 weeks of gestation to approximately 36 weeks of gestation. Maternal insulin requirements may double or quadruple by the end of the pregnancy (see Fig. 29-1, B and C).
Maternal Risk and complications
Hypoglycemia EARLY & LATE PREGNANCY
Poor glycemic control later in pregnancy, particularly in women without vascular disease, increases the rate of fetal macrosomia. Macrosomia has been defined in several different ways, including a birth weight more than 4000 to 4500 g, birth weight greater than the 90th percentile, and estimates of neonatal adipose tissue.
Despite the improvements in care of pregnant women with diabetes, sudden and unexplained stillbirth (birth of a dead fetus) is still a major concern. Typically, this is observed in pregnancies after 36 weeks of gestation in women with vascular disease or poor glycemic control. It may also be associated with DKA, preeclampsia, hydramnios, or macrosomia. Although the exact cause of stillbirth is unknown, it may be related to chronic intrauterine hypoxia
Respiratory distress syndrome
Despite the improvements in care of pregnant women with diabetes, IUFD (sometimes called stillbirth) remains a major concern. Approximately 2% to 5% of all fetal deaths occur in women whose pregnancies are complicated by preexisting diabetes. Hyperglycemia, ketoacidosis, congenital anomalies, infections, and maternal obesity are thought to be reasons for fetal death. In the third trimester, fetal acidosis is the most likely cause of fetal death (Paidas & Hossain, 2009).
Diet & Exercise
Complications ( infections, hypertension)
Fetal surveillance (NST, BIO, ECHO)
Teaching (page 698)
Determination of DOB & Method of birth
In addition to routine prenatal laboratory tests, baseline renal function may be assessed with a 24-hour urine collection for total protein excretion and creatinine clearance. Urinalysis and culture are performed to assess for the presence of a urinary tract infection (UTI), which is common in diabetic pregnancy. Because of the risk of coexisting thyroid disease, thyroid function tests may also be performed (see later discussion of thyroid disorders). The glycosylated hemoglobin A1c level may be measured to assess recent glycemic control. With prolonged hyperglycemia, some of the hemoglobin remains saturated with glucose for the life of the red blood cell (RBC). Therefore, a test for glycosylated hemoglobin provides a measure of glycemic control over time, specifically over the previous 4 to 6 weeks. Hemoglobin A1c levels greater than 6 indicate elevated glucose during the previous 4 to 6 weeks (Gilbert, 2011). Fasting blood glucose or random (1 to 2 hours after eating) glucose levels may be assessed during antepartum visits (Fig. 29-2). Self-monitoring blood glucose records may also be reviewed.
For nonobese women, dietary counseling based on preconception body mass index (BMI) is 30 to 35 kcal/kg/day (Cunningham et al., 2010). In contrast, for obese women with a BMI greater than 30, experts recommend that the caloric intake total 25 kcal/kg/day (Moore & Catalano, 2009). The average diet includes 2200 calories (first trimester) to 2500 calories (second and third trimesters). Total calories may be distributed among three meals and one evening snack or, more commonly, three meals and two or three snacks. Meals should be eaten on time and never skipped. Going more than 4 hours without food intake increases the risk for episodes of hypoglycemia. Snacks must be carefully planned in accordance with insulin therapy to prevent fluctuations in blood glucose levels. A large bedtime snack of at least 25 g of carbohydrate with some protein or fat is recommended to help prevent hypoglycemia and starvation ketosis during the night (Moore & Catalano).
The ideal diet is composed of 55% carbohydrate, 20% protein, and 25% fat, with less than 10% as saturated fat (Cunningham et al., 2010) (see the Teaching for Self-Management box: Dietary Management of Diabetic Pregnancy). Simple carbohydrates are limited. Complex carbohydrates that are high in fiber content are recommended because the starch and protein in such foods help regulate the blood glucose level by more sustained glucose release (Gilbert, 2011; Moore & Catalano, 2009).
Insulin requirements in breastfeeding women may be one half of prepregnancy levels because of the carbohydrate used in human milk production. Because glucose levels are lower than normal, breastfeeding women are at increased risk for hypoglycemia, especially in the early postpartum period and after breastfeeding sessions, particularly after late-night nursing (Gilbert, 2011; Moore & Catalano, 2009). Breastfeeding mothers with diabetes may be at increased risk for mastitis and yeast infections of the breast. The insulin dose, which is decreased during lactation, must be recalculated at weaning (see Fig. 29-1, F).
GDM complicates approximately 3% to 9% of all pregnancies (Moore & Catalano, 2009) and accounts for more than 90% of all cases of diabetic pregnancy (Landon et al., 2007). According to White's classification system, these women fall into classes A1 and A2 (see Table 29-1). GDM is more likely to occur among Hispanic, Native American, Asian, and African-American women than in Caucasians and is likely to recur in future pregnancies; the risk for development of overt diabetes in later life is also increased (Moore & Catalano). This tendency is especially true of women whose GDM is diagnosed early in pregnancy or who are obese (Landon et al.).
The screening test (glucola screening) most often used consists of a 50-g oral glucose load followed by a plasma glucose measurement 1 hour later. The woman need not be fasting. A glucose value of 130 to 140 mg/dl is considered a positive screen and should be followed by a 3-hour (100-g) oral glucose tolerance test (OGTT). The OGTT is administered after an overnight fast and at least 3 days of unrestricted diet (at least 150 g of carbohydrate) and physical activity. The woman is instructed to avoid caffeine because it will increase glucose levels and to abstain from smoking for 12 hours before the test. The 3-hour OGTT requires a fasting blood glucose level, which is drawn before giving a 100-g glucose load. Blood glucose levels are then drawn 1, 2, and 3 hours later. The woman is diagnosed with gestational diabetes if two or more values are met or exceeded (Moore & Catalano, 2009) (Fig. 29-4).
Loss of 5% of prepregnancy weight
Electrolyte imbalance ntk