What changes occur in a woman's metabolism during pregnancy?

During pregnancy, a woman's metabolism undergoes significant changes to support the growing fetus and prepare the body for childbirth. One of the most notable changes is increased insulin resistance. This phenomenon occurs primarily due to the hormonal changes that take place during pregnancy, particularly the increase in hormones such as human placental lactogen and progesterone. These hormones act to ensure that the fetus receives enough glucose and nutrients by causing the mother's body to become less responsive to insulin.

As insulin resistance increases, the mother’s blood sugar levels may rise, prompting the pancreas to produce more insulin to maintain normal glucose levels. This adaptation is crucial for providing adequate energy and nutrients to the developing fetus. However, if the mother's body cannot produce enough insulin to meet the increased demands, it can lead to gestational diabetes.

In contrast, decreased caloric needs, reduced fat storage, and stable glucose levels do not accurately reflect the metabolic changes during pregnancy. The body actually requires increased caloric intake to support fetal growth, fat storage is enhanced to prepare for energy needs during lactation, and glucose levels can fluctuate due to the changes in metabolism and insulin resistance. Thus, increased insulin resistance is the correct response to the question about metabolic changes during pregnancy.