The burdens rarely discussed: how a woman's body changes during pregnancy

External changes in a pregnant woman's body are just the tip of the iceberg of a global systemic restructuring of the organism. Over nine months, the body performs work comparable only to preparing for a marathon — except this "marathon" lasts for months, and the finish line — childbirth — requires a separate resource. Read what science says about changes in a pregnant woman's body in the article by UNN. 

Increase in blood volume 

One of the first and most noticeable changes is an increase in blood volume. A woman's total blood volume increases by approximately 1.5 liters, and by the time of childbirth, it exceeds pre-pregnancy levels by 50%. Most of this additional volume is needed by the uterus and placenta themselves.

An interesting nuance: blood plasma volume increases faster than the number of red blood cells. This causes so-called "physiological anemia of pregnancy" — hemoglobin appears lower in tests, although this is not a disease but a consequence of blood dilution by a larger plasma volume. The body initiates this process as early as the fourth week of pregnancy.

Additionally, a pregnant woman's blood becomes thicker in terms of clotting — this is a natural protection against bleeding during childbirth, but at the same time, a factor of increased risk of blood clot formation. Moreover, as explained in a comment to UNN by the Head of the Department of Hospital Obstetrics and Gynecology and Postgraduate Education of the Bogomolets National Medical University, Professor, Honored Doctor Dmytro Govsieiev, the level of cortisol in a pregnant woman's blood also increases, as does the need for oxygen. 

Heart and lungs: double load

A pregnant woman's heart literally works harder: the volume of blood pumped by the heart per minute increases, blood supply to the kidneys and the uteroplacental complex intensifies. At the same time, many pregnant women experience a decrease in blood pressure. 

Breathing also changes: the depth of breathing increases (by approximately 40%) and its frequency (by approximately 15%). That is, a woman literally breathes more intensely, even at rest.  

The entire body adapts to the needs of protecting the fetus 

As Dmytro Govsieiev points out, a woman becomes more vulnerable to infections during pregnancy. As scientists have found, the immune system of a pregnant woman balances between protecting the woman's body and the ability to "not attack" the fetus. To achieve this, the activity of some types of immune cells decreases while the work of others intensifies.

Other body systems also undergo changes, for example, the thyroid gland increases in volume, and the gastrointestinal tract slows down, leading to typical pregnancy companions — nausea, heartburn, heaviness after eating.

The brain also undergoes changes — it literally restructures itself so that after childbirth, the woman can more easily recognize the baby's needs and form attachment more quickly. 

This process is regulated by the same hormones — estradiol, progesterone, prolactin, oxytocin. After childbirth, some changes gradually return to the previous state.

"Pregnancy is a natural physiological process. The changes occurring in the body of a woman with a normal pregnancy course are not a disease. But during this period, the body requires more attention and care," explains Dmytro Govsieiev. 

Throughout the entire pregnancy, the body works to carry and give birth to a healthy child, not always considering the burdens that the woman actually experiences. That is why during this period, the female body requires particularly respectful treatment, prevention of possible exacerbation of chronic conditions, and monitoring of the slightest changes that may indicate deep internal processes. Therefore, regular medical supervision during pregnancy is not a formality, but a way to timely distinguish normal adaptation from a condition requiring help.