Obstetrics and Gynecology - A.M. Gromova 2000

Changes in the female body during pregnancy
Changes in the central nervous system

During the course of Pregnancy, the processes of inhibition and excitation in the Central Nervous system undergo periodic changes. Following Fertilization and ovum implantation, stimulation of uterine interoceptors and continuous afferent impulses from them induce a focus of persistent excitation in the Cerebral Cortex, known as the gestational dominant. Due to reciprocal relationships, cortical activity itself becomes suppressed, which diminishes its inhibitory effect on the subcortex, thereby releasing the latter from inhibition. Such a relationship between the cortex and subcortical structures persists throughout the first three months of pregnancy and gradually re-establishes toward its end, reaching peak expression during the final 12 days before childbirth. At the same time, the reflex activity of the Spinal Cord increases, leading to heightened uterine sensitivity to various humoral and neural stimuli originating from both the mother and the fetus. With the exception of these two periods, subcortical center activity remains suppressed throughout the entire pregnancy.

The state of central regulation dictates pregnancy-related alterations in the Peripheral Nervous System, which manifest as neuralgic pain—particularly sciatica-like symptoms—occasional leg Muscle cramps, paresthesia, and various visual and auditory disturbances.

In the very Cytology/cytology/16.html">Early stages of pregnancy, the tone of the Autonomic nervous system also increases, which accounts for vasotonic reactions such as hypersalivation, nausea, vomiting, and a tendency toward dizziness. At times, inhibitory processes predominate, leading to the relaxation of smooth muscle in Internal Organs. This contributes to The Development of pyelitis and intestinal atony, subsequently resulting in constipation.