What is Pregnancy? Physiology of Pregnancy

One should bear in mind that pregnancy is a physiological event and not a disease as some think it to be. The feeling of being pregnant is wonderful if experienced with joy. The 10 Months of pregnancy has its ups and downs, but the memories can be cherished when one learns to enjoy being pregnant.


The following are the usual signs and symptoms during pregnancy:

  1. Morning Sickness: Nausea and vomiting may occur even before the menstrual date is missed. This usually starts in the morning specially while brushing the teeth and gradually decreases during the day, and again increase in the evening, This usually lasts from the first few weeks of pregnancy to the 3rd month. A few high strung individuals may vomit more than usual leading to a condition called hyperemesis which could require hospitalisation and intra venous infusion.
  2. Salivation: This is just a collection of water in the mouth which disappears in due course.
  3. Pica of Pregnancy: This is a deferred attitude to food, an abnormal appetite, i.e. a sudden like or dislike to certain type of food.
  4. Drowsiness: This is very common during pregnancy. One feels very lazy and drowsy all the time, resulting in sleeping frequently and developing a lazy attitude.
  5. Frequent micturition: This is a feeling of wanting to pass small quantity of urine all the time. It is due to the pressure of the developing uterus on the bladder neck in early pregnancy. This feeling subsides during midterm of the pregnancy and recurs at a later date near term when the head of the baby descends into the pelvis and presses the bladder.
  6. Constipation: This is another common feature which is due to the presence of the hormone progesterone which relaxes the smooth muscles of the intestines.
  7. Changes in the breast: During pregnancy, striking changes occur in the breast. In early pregnancy, there is a tingling sensation and tenderness in the breast and slowly they start increasing in size, veins over the breast become prominent and the nipples become enlarged and there is darkening around the areola. The glands round the nipple also increase in size. From the 3rd month onwards, clear fluid may be expressed.
  8. Uterine Changes: This is the organ that harbours the child from early pregnancy to term and therefore it increases in size every month and rises out of the pelvis to occupy the abdomen and gives a characteristic contour to the pregnant lady.
  9. Abdominal wall: In the later months of pregnancy, reddish slightly depressed streaks appear in the lower abdomen and also over the breast and thighs called striae gravidarum which after delivery, leaves a permanent scar of silvery white line due to rupture of the muscle fibres which cannot be prevented. This can be controlled by applying Vitamin E oil and refraining from scratching the abdomen.
  10. Heartburn: Burning sensation during early months of pregnancy is due to (1) excessive vomiting (2) delay in gastric emptying. During middle and late pregnancy, the reason is due to change of position of the stomach by the upward growing uterus. This is relieved by bland diet and antacids. hot and spicy food should be avoided.
  11. Breathlessness: A little shortness of breath occurs during middle and later months of pregnancy since the uterus pushes the diaphragm up and the ventilatory capacity of the lungs is reduced.
  12. Muscle cramps: They are frequent especially in the calf and thigh muscles due to the change in the mineral contents of the muscle during pregnancy.
  13. Varicose veins: Prominence of the veins in the lower limbs may occur due to the weight of the uterus pressing on the veins. The increased serum level of progesterone tends to relax the vein walls leading to more varicose veins in the legs, vulva and aggravates piles if present.
  14. Pigmentation: Extra pigmentation of the face, neck and other parts of the body occur due to the disturbance of the hormone production from the anterior pituitary in the brain. The midline of the abdomen gets darkened and this is called linea nigra. The pigmentation of the face is called cholasma. This invariably disappears after delivery.
  15. Fainting attacks: Some women feel dizzy and faint during the early months of pregnancy. This is due to hypoglycemia and a glucose drink will restore the energy lost.
  16. Back pain and joint pains: This is due to the production of the hormone called relaxin which relaxes all the joints, mainly the hip and pelvic joints. This hypermotility of the pelvic joints leads to back pain. Protrusion of the abdomen during pregnancy is a strain to the back muscle which supports the abdomen and this also leads to back pain.

Another important factor is the foetal movement which is felt like a flutter inside the womb, as early as the 16th to l8th week. A woman pregnant for the first time experiences this feelings as late as 18th to 20th week, whereas this is experienced at the earlier stage i.e. 16th to 18th week during the second or later pregnancies.

One of the most commonly asked question that seems to be constantly puzzling the majority of my patients, is regarding the increase in size of the abdomen. I have often had my patients expressing anxiety of their abdomen not become prominent as early as 2-3 months. Normally, the abdomen does not show a prominent increase in size till the 6th month as the muscles are very taut and resist the uterine prominence.

At the 12-14th week, the uterus is just felt at the symphysis pubis. At the 16-20th week it is midway between the symphysis pubis and umblilicus. At the 24th week and 32nd weed, the uterus is between the umbilicus and xiphisternum. At the 38th week, the uterus hits the xiphisternum. At term, the head enters the pelvis and the uterus falls forward and becomes more prominent than usual. This is called lightening since the women feels more comfortable because the pressure on the heart, lungs and stomach is released.

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