Swelling during pregnancy, is the edema (swelling) that is noted in the ankles and legs of most pregnant women, especially during the third trimester. A pitting type of edema (a “pit” is left after a finger presses on the ankle or leg) is usually considered a normal physical change when a pregnant woman’s body adapts to her pregnancy.

 

Usually noticed late during the day, or after prolonged standing, or sitting with flexed knees and hips, swelling during pregnancy is not normally accompanied by pain or numbness.

 

The following contribute to the development of swelling during pregnancy:

 

  • Normal maternal physiological changes during pregnancy which includes increased body water retention, thinning of blood and increased osmotic pressure in the space between the cells can all lead to swelling during pregnancy.

 

  • Mechanical factors (from pressure exerted by the enlarged uterus) such as retarded blood flow from the ankles, legs, and thighs and increased pressure in the veins of the lower limbs can also cause swelling during pregnancy.

 

At full term of normal pregnancy, the average woman retains about 6.5 liters of extra water in her body. This includes water in the products of conception, the size of the womb and breasts, and increased maternal blood volume.

 

A fall in plasma osmolality or a thinning of blood, starting early in pregnancy, together with a decreased tendency to keep water out of the spaces outside the blood vessels, partly mediate the increased water retention that eventually lead to swelling during pregnancy.

 

In the final trimester, the pressure from the enlarged womb pushes on the blood vessels in the pelvis and the inferior vena cava (a large blood vessel that directly drains blood into the right side of the heart). A tendency toward stagnation of blood in the lower limbs occurs. Moreover, pressure in the veins of the thighs reaches up to three times the baseline values at term pregnancy. All of these factors contribute to the development of swelling during pregnancy.

 

An early routine prenatal check-up with a doctor, and continued check up regularly throughout her pregnancy, is a healthy practice and should be followed diligently by a pregnant female. Her regular check-up can give proper assurance regarding the swelling during pregnancy, or otherwise help discover other physical conditions that might need more attention.

 

Urgent consultation for swelling during pregnancy is needed when:

 

  • Swelling during pregnancy includes the hands, face, areas around the eyes
  • Swelling during pregnancy is associated with difficulty of breathing, scanty urine, headache, etc.
  • Blood pressure elevation is present (generally 140/90 mm Hg or higher)
  • There is a history of any adverse physical condition(s) during any previous pregnancy

 

Abnormal swelling during pregnancy may be due to Pregnancy-induced hypertension, Preeclampsia, eclampsia (a condition characterized by high BP and high urine protein level), kidney disease, Hydramnios (abnormal amount of fluid in the uterus) and possible heart disease.

 

With a normal and carefully done prenatal check-up, swelling during pregnancy should not cause worry, and may be helped with the following:

 

  • Sitting with both knees straight or slightly flexed and feet supported by a stool or a stack of books
  • Lying down on your left side (promotes improved blood flow from the lower limbs)
  • Avoiding prolonged standing
  • Avoiding tight-fitting clothing

 

Water or salt restriction is generally not necessary. For example, in swelling during pregnancy complicated by pregnancy-induced hypertension or preeclampsia/eclampsia, the blood electrolyte concentrations do not significantly differ from those in normal pregnancy. Ordinarily, swelling during pregnancy disappears within one week after delivery.