A nurse is caring for a term macrosomic newborn whose mother has poorly controlled type 2 diabetes. The newborn has respiratory distress syndrome. The nurse should be aware that the most likely cause of the respiratory distress is which of the following?
A.
Increased risk of anemia
B.
Hyperinsulinemia
C.
Increased blood viscosity
D.
Brachial plexus injury
The Correct answer and Explanation is:
The correct answer is B. Hyperinsulinemia.
Explanation:
In a term macrosomic newborn, particularly one whose mother has poorly controlled type 2 diabetes, respiratory distress syndrome (RDS) can be linked to several factors. However, hyperinsulinemia is a significant contributing factor. Here’s why:
- Hyperinsulinemia: This condition arises because of the maternal diabetes, which leads to elevated blood glucose levels. In response, the fetus produces excess insulin, a condition known as hyperinsulinemia. High levels of insulin can have several adverse effects on the fetus, including affecting lung maturation. Insulin inhibits the synthesis of surfactant, a substance produced by the alveolar cells in the lungs that reduces surface tension and helps keep the alveoli open. When surfactant production is inadequate, it leads to respiratory distress syndrome (RDS) due to alveolar collapse.
- Respiratory Distress Syndrome (RDS): RDS is primarily a result of surfactant deficiency. The surfactant deficiency in newborns of diabetic mothers is compounded by hyperinsulinemia. This surfactant deficiency leads to difficulty in breathing, atelectasis (lung collapse), and the characteristic symptoms of respiratory distress.
- Other Factors:
- Increased Risk of Anemia (A): While anemia can be a concern in diabetic pregnancies, it is not directly responsible for RDS in this context.
- Increased Blood Viscosity (C): This can occur in newborns of diabetic mothers but does not directly cause RDS. It might lead to other complications such as impaired oxygen delivery, but RDS is more closely linked to surfactant issues.
- Brachial Plexus Injury (D): This injury results from shoulder dystocia and affects arm movement. While it is a possible complication in macrosomic newborns, it does not cause RDS.
In summary, the most likely cause of respiratory distress in this term macrosomic newborn is hyperinsulinemia, which leads to decreased surfactant production and subsequent respiratory distress syndrome.