What does progesterone do during pregnancy?
Because it thickens the uterine lining, progesterone is essential for pregnancy support. A thick uterine lining aids the development of a fertilized egg into an embryo, and subsequently into a fetus.
During pregnancy, progesterone levels continue to climb. While pregnant, high progesterone levels hinder your body from ovulating. It also prevents preterm labour by suppressing uterine contractions. Finally, progesterone helps your breasts prepare for breastfeeding (chestfeeding).
Because progesterone is so critical in the early stages of pregnancy, low progesterone levels may make it difficult to conceive and increase your chance of miscarriage.