Physiological postpartum period

Essence of puerperium and anatomical changes

Normally, the total duration of the postpartum period ranges from 6 to 8 weeks. Obstetricians pay special attention to the early postpartum period—the first 2 hours after the delivery of the placenta, when the most acute adaptation processes take place.

The core of this entire stage lies in the global restructuring of the mother's body. The process of involution is launched—the regression of those colossal changes that formed during pregnancy and labor. Organs gradually return to their baseline state. All these processes are strictly regulated by the complex interaction of the central nervous system, the endocrine apparatus, and the reproductive organs themselves.

However, involution does not affect everything. The main exception is the mammary glands. Their function does not fade after childbirth; on the contrary, it sharply activates. The lactation process can successfully continue for a year or even longer.

In addition, it is important to understand that certain anatomical changes remain with a woman for the rest of her life. Such irreversible consequences include:

• change in the initial size and shape of the mammary glands;
• transformation of the external os of the cervix (it permanently acquires a characteristic slit-like shape);
• appearance of pronounced rugosity of the vaginal walls.

Hormonal restructuring and lactation

The hormonal status of the postpartum woman undergoes perhaps the most significant and abrupt changes. Immediately after delivery, there is a rapid drop in placental hormone levels in the blood. This drop serves as a signal for the hypothalamo-pituitary system to restore its habitual functioning.

A special place in endocrine regulation belongs to the process of milk production. It is divided into two functional stages:

1. To initiate lactation, a powerful hormonal stimulus is required. The start is provided by the combined action of estrogens, progesterone, and prolactin.
2. Subsequently, the maintenance of milk secretion and release is controlled predominantly by two hormones—prolactin and oxytocin.

The restoration of reproductive function directly depends on breastfeeding. As soon as the woman stops feeding (or if a natural decrease in prolactin expression occurs), the cyclical activity of the hypothalamo-pituitary-ovarian system restarts in the body. Concurrently, the full function of the thyroid gland and adrenal glands is completely restored.

The timelines for the appearance of the first ovulatory cycles are:

• about 50 days in non-nursing mothers;
• more than 100 days in women maintaining lactation.

Nervous and cardiovascular systems

Central nervous system After childbirth, a woman's psyche and nervous regulation change radically. The famous "gestational dominance," which determined the woman's condition during pregnancy, fades away. It is replaced by the awakening of the maternal instinct.

During this period, predominant excitation occurs in the cerebral cortex. A pronounced lability of the psyche—emotional vulnerability and mood swings—is extremely characteristic of postpartum women. Against the backdrop of this instability in the postpartum period, depressions requiring attention from physicians are possible.

Cardiovascular system The mother's hemodynamics also goes through serious adaptation. After delivery, three key indicators decrease by approximately 13%:

• blood circulation volume (BCV);
• circulating plasma volume;
• circulating red blood cell volume.

An interesting clinical fact: the decrease in BCV in the early postpartum period exceeds the actual blood loss during labor by 2–2.5 times. The pathogenesis of this phenomenon lies not in external blood loss, but in internal redistribution—massive pooling of blood occurs in the vessels of the abdominal cavity.

Class and exam questions

What else to study on this topic

• Mechanisms of blood pooling in the abdominal cavity after childbirth
• The role of estrogens, progesterone, and prolactin in initiating lactation
• The shift from gestational dominance to maternal instinct
• Prevention and diagnosis of postpartum depressions against the background of psychic lability
• Restoration of the function of the hypothalamo-pituitary-ovarian system

Other topics in the "Obstetrics" section

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.