Glucose metabolism is profoundly affected during pregnancy because: a. pancreatic function in the islets of langerhans is affected by pregnancy. b. a pregnant woman uses glucose at a more rapid rate than a nonpregnant woman. c. a pregnant woman increases her dietary intake significantly. d. placental hormones are antagonistic to insulin, resulting in insulin resistance.

d. Placental hormones are antagonistic to insulin, resulting in insulin resistance.

Explanation:

The placenta secretes many hormones out of which estrogen, progesterone, and human placental lactogen have an antagonistic effect on insulin. Insulin from the pancreas triggers the uptake of glucose by cells and lowers down the blood glucose level. Increased secretion of estrogen, progesterone, and human placental lactogen during late pregnancy by the placenta makes the cells non-responsive or reduces their sensitivity to the presence of insulin. This is called insulin resistance.

When cells do not respond to the presence of insulin by taking up the glucose, the blood glucose levels are increased. This effect increases the availability of glucose to the fetus as the circulating glucose is transported to the fetus.