Physiological changes in pregnancy

Physiological changes in pregnancy

Pregnancy represents a special physiological state during which the woman’s body undergoes extensive changes in order to adapt to the growing fetus and support its health.

These changes also prepare the mothers body for childbirth and lactation.

Every organ system is affected, and the effects are mainly caused by placental hormones and maternal glands.

Why is it important to know about the physiological changes in pregnancy?

In order to distinguish them from pathological changes.

1. Hormonal changes:

** hCG hormone: supports corpus luteum in early pregnancy to maintain progesterone production

**progesterone: relaxes uterine muscles and prevents premature contractions

**estrogen: promotes uterine growth, breast development and increased blood flow

**hPL hormone: modifies maternal metabolism

**relaxin: soften the cervix in preparation for delivery

2. Cardiovascular system changes:

** increased blood volume by 50%

** increased cardiac output by 50%

**decreased systemic vascular resistance

** physiological anemia

**decreased blood pressure

3. Respiratory system changes:

** increased tidal volume

** increased ventilation per minute

** respiratory alkalosis

** elevated diaphragm due to enlarged uterus

** improved oxygenation

4. Renal system changes:

** increased blood flow to the kidneys

** increased glomerular filtration rate by 50%

** mild glucose in urine

** dilatation of ureters

5. Gastrointestinal system changes:

** nausea and vomiting

** reduced motility

** constipation

** heartburn

** increased appetite

6. Hematological changes:

** increased clotting factors leading to thrombosis tendency

** physiological anemia

** increased blood cell mass

7. Musculoskeletal changes:

** relaxation of pelvic ligaments

** lumbar lordosis

** loosening of pelvic joints

These changes lead to lower back pain and altered posture

8. Skin changes:

** increased pigmentation

** increased sweating

** increased activity of sebaceous glands

** palmar erythema

Understanding these changes helps the obstetrician differentiate normal physiology from evolving pathology to provide optimal maternal and fetal care.

Dr Najeeb Layyous  F.R.C.O.G

Consultant Obstetrician, Gynecologist and Infertility Specialist