North American Registry of Midwives (NARM) Practice Exam

What is the course of normal progesterone levels during pregnancy and labor?

1. They remain constant

2. They increase and then decrease before labor

3. They decrease after conception

4. They fluctuate widely

The correct answer is: They increase and then decrease before labor

During pregnancy, progesterone plays a crucial role in maintaining the uterine environment conducive to fetal development. After conception, progesterone levels rise steadily, as it is essential in preparing the endometrium for implantation and maintaining pregnancy. In the early stages of pregnancy, progesterone is produced primarily by the corpus luteum, and its levels continue to increase as the placenta takes over production around the end of the first trimester. This increase supports the growth and development of the fetus. As labor approaches, however, there is a notable decrease in progesterone levels. This drop is important because progesterone is known to inhibit uterine contractions. When progesterone levels decrease, this allows for an increase in uterine activity, facilitating the onset of labor. Therefore, the understanding that progesterone levels increase during pregnancy and then decrease before labor directly correlates with the physiological changes that prepare the body for childbirth, affirming the correct answer.