Nursing Care for Pre-existing Conditions Impacting Pregnancy

Pre-existing medical conditions are chronic medical problems that are present before pregnancy that can pose a risk to the patient and fetus during pregnancy. These can include diabetes mellitus and heart failure, both of which require special monitoring and treatments to support the health of the patient and developing fetus throughout pregnancy.

Diabetes mellitus is a condition where there's an excess amount of glucose in the blood, called hyperglycemia. Type 1 diabetes is caused by autoimmune destruction of beta cells in the pancreas that are responsible for producing insulin, a hormone that helps glucose to move into cells. On the other hand, type 2 diabetes is a result of genetic, environmental, and lifestyle factors, that primarily results in insulin resistance, where the body’s cells don’t respond normally to insulin, which impairs their ability to take up glucose from the blood.

Now, during pregnancy, all the nutrients the fetus receives come directly from the mother's blood through the placenta, and glucose is the primary source of energy needed for growth and development. To ensure there’s a steady supply of glucose for the fetus, hormones released by the placenta increase maternal resistance to insulin, resulting in higher levels of maternal glucose. In patients with pre-existing diabetes, this increases the risk for hyperglycemia.

Complications of hyperglycemia in the mother include an increased risk of an operative delivery, due to a large fetus; preeclampsia; and premature labor; as well as worsening of chronic complications of diabetes like retinopathy, kidney disease, and cardiac disease. In the fetus, excessively high levels of glucose can lead to macrosomia, or a birth weight more than 4000 grams; congenital anomalies; intrauterine growth restriction; delayed lung maturity; birth injuries; and even death. During pregnancy, treatment of diabetes begins with diet and exercise to control glucose levels, as well as close glucose monitoring and antepartum fetal assessment. Pre-pregnancy pharmacotherapy typically needs to be modified to meet the goal of glycemic control while ensuring sufficient glucose to meet the demands of the growing fetus. These modifications may include altering the dosage of hypoglycemics or discontinuing them in favor of insulin, which is the preferred medication during pregnancy. Insulin requirements will gradually increase as pregnancy progresses and anti-insulin hormones continue to rise. Then, after birth, insulin requirements decrease due to a sharp drop in anti-insulin hormones.

Heart Failure Heart failure occurs when the heart is unable to pump enough blood to support the body’s demands.