What Is a Healthy Pre-Pregnancy Weight?

Healthy Weight

• Healthy weights for a woman who is not pregnant range from 97 lbs. to 183 lbs. Some women would be considered obese at 183 lbs., and some women would be considered severely underweight at 97 lbs. A woman's healthy weight takes into account her height, frame and build, and muscle. Muscle weighs more than fat, although it takes up less space. Since the range of healthy weights is so large, it is best to consider other factors when determining a healthy pre-pregnancy weight (see Resources for healthy weight calculators).

Body Mass Index

• Body mass index (BMI) is a bit more accurate picture of a whether a woman's pre-pregnancy weight is in the healthy range. BMI takes into account not only weight but height. A person with a BMI of 18.5 or less is considered underweight. A person between 18.5 and 24.9 is a normal weight. A BMI between 25 and 29.9 is considered overweight and anything over 30 is considered obese and means the person is at risk for many diseases connected to unhealthy weight. A woman whose BMI is in the normal range is most likely at a healthy weight to become pregnant, but BMI does not take everything into consideration, such as body type, frame size and muscle content. For example, a woman with a BMI of 25.2 is technically overweight but if that woman works out regularly and has a great deal of muscle, her BMI is not an accurate picture of her health (see Resources for a BMI calculator).

Eating Habits

• Other than actual weight and BMI, a woman's eating habits should be considered when deciding if she is at a healthy weight to become pregnant. A woman who appears to be at a healthy weight but has poor eating habits is likely to gain too much weight during pregnancy and may not get the proper nutrients for a healthy baby. On the other hand, a woman who is considered slightly overweight but has very good eating habits will most likely have a healthy pregnancy. A woman who wants to become pregnant in the near future should focus on eating well and improving her general health. During pregnancy, many women find that they are unable to eat as well due to morning sickness and food aversions. Beginning the pregnancy as healthy as possible is the best way to get through the times when healthy eating is not possible during pregnancy.

Risks of Being Underweight During Pregnancy

• A woman who is underweight does not have enough fat stores on her body to sustain a pregnancy. For this reason, doctors recommend that a woman who is underweight gain 40 lbs. during pregnancy. Gaining that much wait ensures that the woman develops a healthy amount of fat that the body will use up while the baby is growing and also during the months following the birth for breast-feeding. A woman who is underweight who does not gain enough weight during pregnancy is at risk for birth defects, preterm labor, premature birth, or a baby with a low birth weight, which can lead to health problems for the baby.

Risks of Being Overweight During Pregnancy

• A woman who is overweight pre-pregnancy is not as healthy as she could be going into the pregnancy. She is at risk for pre-eclampsia, which can turn fatal if not monitored. She has a higher chance of developing gestational diabetes and even permanent diabetes. A woman who is overweight is more likely to need a c-section. Sadly, stillbirths occur more often when a woman is overweight. A doctor may recommend that a woman who is very overweight or obese gain little or no weight during pregnancy. Sometimes, very overweight women actually find that they lose weight during pregnancy, although that is not always the case.