What is the physiology of lactation

While the growing uterus largely rests until about a month before the appointment and the feto-placental unit is undisturbed, it is finally sensitized by changing the receptor configuration and increasing endocrine stimuli: rhythmic contractions (labor) occur. These have different functions: They increase in intensity and frequency (lower, pre- and opening contractions), cause the birth (pressure contractions), remove the placenta postpartum (afterbirth contractions) and help with hemostasis and regression (after-labor).

The motor function of the uterus is controlled by multiple endocrine factors such as estrogens, oxytocin, relaxin and prostaglandins. Estrogens increase the number of oxytocin receptors - peripartum up to 200-fold, supported by falling progesterone levels. The Ferguson reflex intensifies the contractions, which further increases the stretching stimulus and the release of oxytocin and, together with the high density of receptors, maximizes labor.

The birth-related changes in the fetus / newborn include the change from fetal to independent circulation, the expansion of the lungs, and the change in blood gas values.

Prolactin makes the mammary gland grow and supports milk production; Oxytocin triggers the contraction of myoepithelial cells during breastfeeding and thus lactation. In addition to lactose, fat, proteins, minerals and vitamins, breast milk also contains immunological protection (antibodies).