What is the effect of placental hormones on insulin resistance during pregnancy?

During pregnancy, placental hormones play a significant role in modulating insulin resistance, primarily to ensure a steady supply of glucose to the developing fetus. The secretion of hormones like human placental lactogen (hPL), cortisol, and progesterone increases during pregnancy. These hormones promote insulin resistance in the mother’s body, which helps to elevate blood glucose levels. This mechanism is crucial because it allows for adequate glucose availability for the fetus while effectively redirecting maternal glucose metabolism.

The increase in insulin resistance is a normal physiological adaptation during pregnancy, which also sets the stage for conditions like gestational diabetes if the mother's body cannot produce enough insulin to overcome the increased resistance. Therefore, the correct answer is that placental hormones increase insulin resistance, highlighting their vital role in maternal and fetal health during gestation.