random plasma glucose level >200 mg/dL plus classic signs and symptoms such as polydipsia, polyuria, and unexplained weight loss, or those with a fasting glucose levelr> 125 mg/dL are considered by the ADA (2017 a) and the World Health Organization (2013) to have overt diabetes first detected in pregnancy. Women with only minimal metabolic derangement may be more diicult to identiY. To diagnose overt diabetes in pregnancy, he International Association of Diabetes and Pregnancy Study Groups (IADPSG) Consensus Panel (2010) recognizes the threshold values found in Table 57-4 for fasting or random plasma glucose and glycosylated hemoglobin (HbA1J levels at prenatal care initiation. The ADA (2017a) and the World Health Organization (2013) now also consider a plasma glucose level >200 mg/dL measured 2 hours after a 75 g oral glucose load to be diagnostic. No consensus has been reached as to whether such testing should be universal or limited to those women classiied as high risk. Regardless, the tentative diagnosis of overt diabetes during pregnancy based on these thresholds should be conirmed postpartum. isk factors for impaired carbohydrate metabolism in pregnant women include a strong familial history of diabetes, prior delivery of a large newborn, persistent glucosuria, or unexplained fetal losses.
With overt diabetes, the embryo, fetus, and mother frequently experience serious complications directly attributable to diabetes.
Peterson and colleagues (2015) estimate that thousands of these complications might be prevented each year by preconceptional care for improved glycemic control. The likelihood of successful outcomes with overt diabetes, however, is not simply related to glucose control. The degree of underlying cardiovascular or renal disease may be more important. Thus, advancing stages of the White classification, seen in Table 57-2, are inversely related to favorable pregnancy outcomes. Shown in Table 57-5 are data that chronicle the deleterious pregnancy outcomes with overt diabetes. hese maternal and fetal complications are described in the following sections.
Spontaneous Abortion. Several studies have shown that early miscarriage is associated with poor glycemic control (Chap. 18, p. 347). Up to 25 percent of diabetic gravidas have an early pregnancy loss (Galindo, 2006; Rosenn, 1994). hose whose HbA1c concentrations were > 12 percent or whose preprandial glucose concentrations were persistently > 120 mg/dL had an elevated risk. Bacon and associates (2015) reviewed 89 pregnancies in women with maturity-onset diabetes of the young (MODy), which is a monogenic form of diabetes. hese investigators found that only women with the causative glucose kinase gene (GCK) mutation were more likely to have a miscarriage. These women are characterized by hyperglycemic variability that is diicult to control.
TABLE 57-3. Proposed Classification System for Diabetes in Pregnancy
Gestational diabetes: diabetes d during pregnancy that is not clearly overt (type 1 or type 2) diabetes
Type 1 Diabetes: Type 2 Diabetes:
Diabetes resulting from �-cell destruction, usually leading to Diabetes from inadequate insulin secretion in the face of a.
Without vascular complications a. Without vascular complications b.
With vascular complications (speciy which) b. With vascular complications (speciy which)
Other types of diabetes: genetic in origin, associated with pancreatic disease, drug-induced, or chemically induced
Data from American Diabetes Association, 2017a.