Understanding Weight Gain And Loss During Pregnancy

By:    Published: November 1, 2011

a a a

Weight gain and weight loss are one of the hallmarks of pregnancy. But how much weight should a woman gain? What about weight loss? Is it safe? Here, you will find the answer to these questions and more.

How Women Gain Weight During Pregnancy

Weight gain is healthy for most women during pregnancy. The reason is that there are a number of changes that occur in the body that add to a woman's weight. They are;

  • Baby: The average baby weighs about 8 pounds
  • Placenta: 2 to 3 pounds
  • Amniotic fluid: 2 to 3 pounds
  • Breast Tissue: 2 to 3 pounds
  • Increased blood volume: 4 pounds
  • Fat stores for birth and breast feeding: 5 to 9 pounds
  • Uterine increase: 2 to 5 pounds

This is just a guideline for healthy women. If a woman is underweight or overweight, she may need to carefully monitor any weight changes during pregnancy.

Is Weight Loss Healthy During Pregnancy

For the average, healthy woman, weight loss over the course of the pregnancy is not recommended. However, weight loss during the first trimester of pregnancy is quite common, even in normal healthy women. There are a couple of reasons for this:

  • First, women often experience morning sickness during the first trimester because of the changes that occur rapidly at this stage of pregnancy. If a woman experiences more severe morning sickness, she may actually lose weight as her body uses her fat stores to maintain function and support her baby's growth. If this happens, the woman's doctor will likely monitor her weight closely to ensure that her baby isn't in danger.
  • The other reason is that in the first trimester, even if the woman is not vomiting, overwhelming nausea can make it hard to eat anything. Often times, the only thing that a woman can eat is crackers or toast, which doesn't really have the nutritional content that a growing baby needs. If a woman can't really eat much, she at least needs to be sure to take her prenatal vitamins to ensure that her baby gets all the nutrients it needs.

Some women who are significantly overweight may be able to safely lose weight during pregnancy. This should not be undertaken on one's own however. If a woman is concerned about her weight, she needs to speak with her midwife or obstetrician about safely losing weight during pregnancy. In most cases the doctor will monitor the woman's weight carefully, and the pregnancies of many significantly overweight women are considered high risk pregnancies anyway.

Appropriate Weight Gain

In case you didn't do the math above, the appropriate amount of weight gain for a healthy woman is 25 to 35 pounds over the course of the pregnancy. If a woman is underweight, she may need to gain more, and, as noted above, if a woman is overweight, she may need to gain less.

Most of the weight gain occurs in the last two trimesters of the pregnancy. During the first trimester, women typically gain 2 to 4 pounds. However, in the last two trimesters, average weight gain is about 1 pound per week until delivery.

If a woman is expecting multiple babies, such as twins, she will need to gain more weight. A healthy woman expecting twins should gain 35 to 45 pounds over the course of the pregnancy. The initial weight gain is the same as for a single baby, about 2 to 4 pounds, but after, the normal weight gain is about a pound and a half each week until birth.

Remember:

  • A healthy woman should gain 25 to 35 pounds during pregnancy
  • Normal weight gain is 2 to 4 pounds in the first trimester regardless of the number of babies
  • In the second and third trimester normal weight gain is 1 pound per week until birth
  • If a woman is having twins she should gain a pound and a half each week until birth.

Risks of Gaining Too Much Weight

There are a number of risks to both mother and child if the mother gains too much weight during her pregnancy. According to a study in the Journal of Obstetrics and Gynecology, a woman who gains more than 40 pounds during her pregnancy is more than twice as likely to have a heavy baby. This means that mom may need to have a C-section if the baby is too large. It also means that the child is more likely to be obese later in life.

Another study in the same journal finds that a woman who gains too much weight is also at risk for developing gestational diabetes, which can have a host of complicating effects for both mother and child.

Exercise and Diet

It is important to maintain a healthy lifestyle during pregnancy. Eating a healthy diet and exercising regularly will not only keep mom healthy, but will also help baby develop properly. A woman's midwife or obstetrician can provide information about diet and exercise that is specific to her, but in general she should consume lots of fruits, vegetables, protein and complex carbohydrates. Mom should avoid overly processed foods and refine simple carbohydrates like white sugar.

Contrary to popular myth, a woman does not need to eat for two. She only needs 100 to 300 extra calories to meet her growing baby's needs and keep her weight in check.

Pregnancy is a wonderful time and if a woman maintains a healthy weight, she'll feel better and be able to just sit back and enjoy her pregnancy.

Sources:

More in Health A-Z
New on SymptomFind
a a a  
RELATED ARTICLES
NEED ANSWERS?