Which maternal endocrine change often leads to insulin resistance during pregnancy?

During pregnancy, the body undergoes various hormonal changes that support fetal development and prepare the mother for the metabolic demands placed upon her. One significant change is the increased production of human placental lactogen (hPL), which is produced by the placenta.

hPL plays a crucial role in the modulation of maternal metabolism. It promotes insulin resistance by altering maternal glucose metabolism, ensuring that sufficient glucose is available for the fetus while simultaneously encouraging the mother to utilize fat stores for her energy needs. This insulin resistance is a normal adaptation during pregnancy; it allows for greater nutrient availability to the growing fetus while ensuring that the mother can meet her own metabolic requirements.

This increase in insulin resistance can lead to higher levels of maternal blood glucose, and in some cases, it can contribute to the development of gestational diabetes. Thus, the elevation of hPL is a key factor in the hormonal changes that lead to insulin resistance during pregnancy.

In contrast, the other options do not have the same direct impact on insulin sensitivity. Decreased levels of progesterone do not typically contribute to insulin resistance; instead, progesterone has various roles in maintaining pregnancy. Elevated estrogen levels also play important roles during pregnancy, but they do not specifically induce insulin resistance the way hPL does.