Impact of Pregnancy on Complications of Insulin-Dependent Diabetes Mellitus

ABSTRACT

The effects of pregnancy on acute metabolic complications of diabetes may have important consequences for both mother and fetus. The consequences of pregnancy for chronic complications of diabetes, including retinopathy, nephropathy, neuropathy, and hypertension, are not clear. Recent data are reviewed so that health care providers will be able to provide reasonable advice to insulin-dependent diabetic women contemplating pregnancy both for problems that may potentially arise during gestation and those that may affect long-term health and survival. Diabetic ketoacidosis is an uncommon problem that arises during gestation. Acute alterations in pH and electrolyte concentrations as well as hyperglycemia, however, may have important consequences for mother and fetus, including perinatal asphyxia and reduced fetal oxygen delivery. Hypoglycemia, on the other hand, may result in maternal coma or seizures and, when frequent, has been associated with infant respiratory distress syndrome. Background retinopathy often worsens during gestation, with regression common postpartum. Data suggest that progression of background disease is related to both glycemic control and the acute institution of intensive insulin therapy with those patients with poor control requiring more aggressive therapeutic intervention most adversely affected. The course of proliferative retinopathy is more variable, with both progression and regression reported. Preconception photocoagulation may prevent progression. Preconceptional ophthalmologic evaluation with frequent assessments during pregnancy is advised. Increases in 24-hour protein excretion are common during gestation in patients with preexisting renal disease and resolve in many patients postpartum. Serum creatinine and creatinine clearance increase during the first trimester and generally do not change during the remainder of pregnancy. Patients with preexisting renal disease and hypertension are at risk for development of preeclampsia, whereas nephropathy appearing during gestation is significantly associated with perinatal asphyxia. Although pregnancy per se does not appear to affect progression of diabetic nephropathy, the long-term implications for maternal well-being and survival are serious and preconceptional counseling is warranted.