International Board of Certified Lactation Consultant (IBCLC) Practice Exam

What transition occurs in milk production control around day 9 postpartum?

1. From autocrine to endocrine

2. From endocrine to autocrine

3. From neural to systemic

4. From systemic to local

The correct answer is: From endocrine to autocrine

Milk production control transitions from an endocrine mechanism to an autocrine mechanism around day 9 postpartum. Initially, during the early days after birth, the hormonal influences (primarily prolactin) are prominent, leading to the establishment of milk supply. This phase is characterized by the mother’s body responding to the hormonal cues that promote milk synthesis and secretion. As lactation progresses, especially by around the 9th day postpartum, the control shifts to an autocrine system. In this phase, the milk supply becomes regulated by the local needs of the infant directly through the emptying of the breasts. The more the baby feeds, the more milk is produced, creating a feedback loop that helps to align milk supply with demand. This autocrine regulation allows for a more responsive and individualized milk production system, ultimately supporting the infant’s growing needs. Understanding this transition is crucial for lactation consultants as it informs them about the physiology of lactation and helps guide their recommendations for feeding and managing breastfeeding-related issues during this early postpartum period.