International Board of Certified Lactation Consultant (IBCLC) Practice Exam

What signifies the onset of copious milk secretion?

1. Lactogenesis I

2. Lactogenesis II

3. Galactopoiesis

4. Involution

The correct answer is: Lactogenesis II

The initiation of copious milk secretion is best characterized by Lactogenesis II. This phase follows Lactogenesis I, which occurs during pregnancy and is associated with the preparation of the milk-making system in the breasts, resulting in the production of colostrum. However, it is during Lactogenesis II that there is a significant increase in milk volume and the transition to mature milk. This phase typically happens two to three days postpartum and is triggered by several physiological changes, including a drop in progesterone levels that occurs after the delivery of the placenta, which facilitates the onset of abundant milk production. In the context of lactation, Galactopoiesis refers to the maintenance of established milk production, while Involution denotes the process of the breast returning to its pre-pregnancy state after weaning or the cessation of breastfeeding. While both stages are important in the overall lactation process, they do not signify the initial surge in milk supply that characterizes Lactogenesis II.