In May 2009, The Institute of Medicine (IOM) made changes to the guidelines concerning weight gain during pregnancy. The last recommendations had been released in 1990 and many things have changed since then about the childbearing woman. Taking into consideration the demographics of the current childbearing woman, the IOM made their new guidelines using the World Health Organization’s (WHO) body mass index (BMI) as the starting point. These new guidelines give women a clear range of what a healthy weight gain looks like to help them avoid pregnancy complications such as gestational diabetes, preeclampsia, and cesarean delivery.

Talking to your health care provider about your weight gain is important. Try not to worry if you’re slightly above or below these weights.

Facts about weight gain:

• For women who were a normal weight before pregnancy with a BMI of 18.5-24.9 the recommended weight gain guideline is 25-35 pounds.
• Women who are underweight pre-pregnancy with a BMI of less than 18.5 should gain between 28-40 pounds unless your health care provider says differently.
• Women who begin pregnancy overweight, with a BMI of 25-29, should gain between 15-25 pounds unless your health care provider says differently.
• Women who are obese with a pre-pregnancy BMI of 30 or more should strive for a weight gain of 11-20 pounds unless directed differently by your health care provider.
• Eating healthy meals will allow you to gain adequate weight during your pregnancy. Putting on weight that is unnecessary is easy to do when eating junk food and foods that are higher in fat.
• Eating a well-rounded diet is important. According to the American Congress of Obstetricians and Gynecologists, a pregnant woman of normal weight, who gets less than 30 minutes of exercise a week should strive for a caloric intake of 1,800 during the first trimester, 2,200 during the second trimester and 2,400 during the third trimester.
  These calories should be attained by eating a diet of grains, dairy, protein, fruits/vegetables and healthy fats and oils. Limiting processed foods, sugars and extra fats can help you attain your goals.

Weight distribution in the average woman:

• 7 1/2 pounds is about how much the baby will weigh by the end of pregnancy.
• 1 1/2 pounds is how much the placenta weighs.
• 4 pounds is attributed to increased fluid volume.
• 2 pounds is the weight of the uterus.
• 2 pounds is the weight of breast tissue.
• 4 pounds is because of increased blood volume.
• 7 pounds is attributed to maternal stores of fat, protein and other nutrients.
• 2 pounds for the amniotic fluid.
• Total: 30 pounds

On a trimester basis in a woman with a normal pre-pregnancy weight:

• First trimester: 1-4.5 pounds
• Second trimester: 1-2 pounds per week
• Third trimester: 1-2 pounds per week

Remember this is just an average; you and your health care provider need to decide what is best for you.

Source: American Pregnancy Association