Recommended Weight Gain

Adequate weight gain for a mother is one of the best predictors of pregnancy outcome. According to the National Academy of Sciences, a woman of normal weight (based on BMI) should follow a diet that allows for approximately 2 to 4 pounds (0.9 to 1.8 kilo­grams) of weight gain during the first trimester, and then a subsequent weight gain of 0.75 to 1 pound (0.3 to 0.5 kilograms) weekly during the second and third trimesters. Total weight gain goal normally averages about 25 to 35 pounds (11.5 to 16 kilo­grams). Adolescents and African-American women, who often have smaller babies, are strongly advised to aim for the greater amount. Women carrying twins should gain 35 to 45 pounds, and women carrying triplets should gain 50 pounds (23 kilograms).

For women at a low BMI, the goal increases to 28 to 40 pounds (12.5 to 18 kilo­grams) (Table 13.1). The goal decreases to 15 to 25 pounds (7 to 11.5 kilograms) for a woman at a high BMI, and less than 15 pounds (7 kilograms) for an obese woman. Figure 13.4 shows why the typical recommendation begins at 25 pounds.

A weight gain of between 25 and 35 pounds has repeatedly been shown to yield optimal health for both mother and fetus if gestation lasts at least 38 weeks. The weight gain should yield a birth weight of 7.5 pounds (3.5 kilograms). Although some extra weight gain during pregnancy is usually not harmful, it can set the stage for creeping obesity during the childbearing years if the mother does not return to about her prepregnancy weight. This is especially true if the woman intends to have more than one child.

Weight gain during pregnancy, especially in the teenage years, requires regular monitoring that approximately. Infant birth weights improve if the mother's weight gain meets the ranges previously mentioned. Keeping weekly records of a pregnant woman's weight gain helps assess how much to adjust her food intake. Weight gain is a key issue in prenatal care and a concern of many mothers. Inadequate weight gain can cause many problems. If a woman devi­ates from the desirable pattern, she should be warned of this and counseled on how to make the appropriate adjustment.

For example, if a woman begins to gain too much weight during her pregnancy, she should not be encouraged to lose weight to get back on track. Even if a woman gains 35 pounds in the first 7 months of pregnancy, she must still gain more during the last 2 months. Weight loss is never advised. She should simply slow the increase in weight to parallel the rise on the prenatal weight gain chart. In other words, the sources of the unnecessary food energy should be found and minimized. Alternately, if a woman has not gained the desired weight by a given point in pregnancy, she shouldn't be en­couraged to gain the needed weight rapidly. Instead, she should slowly gain a little more weight than the typical pattern to meet the goal by the end of the pregnancy.