Certified Breastfeeding Counselor (CBC) Practice

What happens to progesterone levels during Lactogenesis 1?

1. They increase

2. They remain the same

3. They decrease

4. They fluctuate

The correct answer is: They fluctuate

During Lactogenesis 1, which occurs during the second half of pregnancy, the levels of progesterone actually decrease as the body transitions towards initiating milk production. This phase is characterized by the preparation of the breast tissue for lactation influences by several hormones. As the placenta is delivered, progesterone levels drop significantly, allowing for the stimulation of milk-producing cells. The establishment of Lactogenesis 1 is primarily influenced by the hormone prolactin, which rises in response to the fall in progesterone. This decrease in progesterone is crucial because high levels of progesterone inhibit milk secretion. Hence, the correct understanding is that there is a decrease in progesterone levels during this phase, facilitating the physiological changes necessary for milk production to begin.