The caloric cost of pregnancy

Nutr Rev. 1973 Jun;31(6):177-9. doi: 10.1111/j.1753-4887.1973.tb05170.x.

Abstract

PIP: To determine the amount of extra calories a pregnant woman needs to ensure normal growth of her fetus, a study was conducted using 11 normal women who were willing to spend 1 week in the hospital during the last half of pregnancy. The women were given a constant diet of known composition which closely approximated their normal diet at home. Data on fasting weight and fluid balance, nitrogen excretion (from urine samples), 24-hour oxygen consumption and CO2 production were recorded daily. The diet consisted of 80 gm. or more of high-quality protein and supplementary vitamins and iron. 7 women were in positive caloric balance eating 1600 to 2000 Kcal/day; their mean weight gain was 6.8 kg. The other 4, who were obese or who were prone to obesity, were on a lower caloric intake of 1200 to 1600 Kcal/day; despite this, their average gestational weight gain was 10.0 kg. All babies, except for 1 (the mother had placental insufficiency due to low implantation, premature separation, and antepartum hemorrhage; her baby weighed 2.58 kg. at 38 weeks), were born at term with a birthweight of more than 3 kg. The authors concluded that pregnancy hardly imposes any increase in physical activity on the women, and whatever physical effort is exerted is offset by a reduction in physical activity. A pregnant woman requires approximately 600 Kcal. daily for her activities; this amounts to total caloric requirements of 2100, 2200 and 2300 Kcal/day in each of the 3 trimesters. 12 oz. of homogenized milk per day is adequate to meet the extra caloric requirements of a well-nourished woman during her pregnancy. The findings suggest that a normal woman need not overeat to ensure normal growth of her fetus.

Publication types

  • Review

MeSH terms

  • Body Constitution
  • Calorimetry
  • Diet
  • Embryonic and Fetal Development
  • Female
  • Humans
  • Metabolism*
  • Nitrogen / metabolism
  • Nitrogen / urine
  • Nutritional Physiological Phenomena
  • Oxygen Consumption
  • Pregnancy*
  • Respiration
  • Time Factors

Substances

  • Nitrogen