Weight Gain

Pregnancy is not the time to diet. As your pregnancy progresses, your appetite will increase. This is nature's way of making sure that you eat enough for you and your baby. In fact, a woman should increase her caloric intake — most pregnant women require an additional 300 calories a day over their pre-pregnancy needs — and gain weight during pregnancy. Adjustments to caloric intake may be required with increased or unusual levels of physical activity.

For a woman of average weight-for-height, the suggested average pregnancy weight gain is 28 pounds with a suggested range of 25 to 35 pounds, with underweight women encouraged to gain as much as 40 pounds. The recommended weight gain range for overweight women is 15 to 25 pounds. Overweight women should not diet or attempt to lose weight during pregnancy. It is, however, an ideal time for an overweight woman to change her eating habits. The typical breakdown of pregnancy weight gain is as follows:

Maternal weight gain is partitioned differently between mother and fetus during pregnancy. Maternal fat stores are deposited early in pregnancy and reach peak level of maternal deposit midway through pregnancy. It is thought to represent the energy reserve that may be required to feed the rapid fetal growth occurring in the last 10 weeks of the pregnancy.

Placental growth and maternal increase in organ weight and blood occurs rapidly in mid-pregnancy in anticipation of the increasing metabolic requirements of the pregnant woman and the very rapid growth and energy requirements of the fetus in the last quarter of the pregnancy. Maternal fat stores deposited early in pregnancy and not used for the pregnancy are available to support the maternal energy requirements for lactation.

Research has shown that when mothers-to-be eat poor diets, there is an increase in risk of low-birth-weight infants, particularly in women with poor health and nutrition status before pregnancy. The risk is compounded by lifestyle choices, such as smoking, that may affect pregnancy outcome. However, gaining too much weight is not good for you either. Women who are overweight can experience problems during pregnancy. And fat that is deposited at the tops of the arms and the thighs is very difficult to shed after pregnancy.

Eating healthy snacks during the day is a good way to get needed nutrition and calories without gaining too much weight. Choosing such foods as fruits, yogurt and unsweetened cereal, instead of chocolate bars, soda and potato chips, will provide you with the right nutrients, with sugar or fat.

Ideally, you should gain 3 to 8 pounds in the first three months (first trimester) of pregnancy and 3/4 to 1 pound a week after that. The most rapid weight gain occurs in the last three months. A week or two after the baby is born, you'll lose about 18 to 20 pounds. Unless your weight gain was excessive, you will return to your pre-pregnancy weight in about four to six months.

Rarely, some women will retain a lot of fluid in the last weeks of pregnancy. Retaining such fluid may be evident in a sudden gain of several pounds in a week and in swelling (edema) of the hands and face. Such fluid retention may be a sign of preeclampsia (toxemia). It is for this reason that your provider will see you each week at the end of pregnancy and follow your weight gain and well-being closely.