Nutrition for Special Groups 3(3+0)

Lesson 7 : Nutrition During Pregnancy


A woman’s body is the environment in which a new human being grows. Therefore the health of the woman’s body influences her fertility, the health of the infants she may later conceive and bear and her own health later in life.
The time before conception provides a unique opportunity for a woman to prepare herself physically, mentally and emotionally for the many changes to come. She has to develop and establish healthful habits so that her body becomes a suitable environment for the fetus to develop.

  • Maintaining a healthy body weight is very important and any woman who plans a pregnancy should achieve and maintain an ideal body weight. A woman’s weight before conception influences her health throughout pregnancy and the fetus development. Both underweight and overweight women and their newborns face greater risks than others.
  • Eating a diet adequate in nutrients is essential; the diet should be particularly adequate in calcium, iron and folate. A varied diet generally meets all nutrient requirements except iron. When necessary nutrient supplements need to be given.
  • Physical activity is important for good health, but strenuous activity should not be started during pregnancy.
  • Avoidance of harmful environmental factor like excessive alcohol consumption, smoking, drug usage etc. is important.

Once pregnancy occurs, various physiological events bring major changes to the mother’s body, creating an entire new organ within it- the placenta- and producing a new human being.
The placenta transfers oxygen and nutrients to the fetus and returns carbon dioxide and other fetal waste products to the mother.

Glucose is the main energy source for fetal growth and the placenta transfers it to the fetus. Water, oxygen, CO2 and electrolytes cross the placenta by passive diffusion. Glucose, calcium, phosphorus, magnesium and other nutrients cross the placenta via active transport. The fetus accumulates these nutrients throughout pregnancy. Thus a healthy placenta is essential for the developing fetus to attain its full potential. Maternal nutrition is crucial to placental development. Maternal malnutrition limits placental development which reduces placental blood flow. A diminished blood flow curtails transfer of nutrients to the fetus. Thus maternal malnutrition negatively affects the fetus by

  • Impairing placental development
  • Reducing transfer of nutrients across the placenta

Malnutrition exerts its effects during critical periods of development. The intense development and rapid cell division are critical periods- critical because the events scheduled for that time can occur only at that time. If cell division and final cell number achieved in an organ are limited during a critical period, full recovery will not occur.

Early malnutrition can have an irreversible effect which may not become fully apparent until the person reaches maturity. Research suggests that adverse influences at critical times lead to chronic diseases in adult life. Body functions like immune function, blood pressure, cholesterol metabolism etc are altered because of malnutrition during critical periods.

For instance, the beta cells of the islets of Langerhans are increased in number by 130 times between 12 weeks of fetus and birth of infant are primarily determined by the nutritional status of the mother Infants who are malnourished have less number of these cells.
Thus each organ or tissue is vulnerable to nutrient deficiencies during its own critical period. For e.g the critical period for the formation of the neural tube- which is the beginning of brain and spinal cord is 17-30 days of gestation. Any under nutrition, especially low levels of folic acid, can cause a major defect in the nervous system. Because critical periods occur throughout pregnancy, a woman should continuously take good care of her health.

Last modified: Wednesday, 2 May 2012, 1:01 PM