Women are expected to gain some weight during pregnancy. It is natural and healthy for both mother and child. But should an obese woman gain weight during pregnancy, and if so, how much and when? A new study suggests that women who are obese should not gain any weight until mid-pregnancy or later.
The study creates guidance to help physicians and obstetricians advise women who are obese and pregnant on how much weight they should gain. Reference charts for these women had not existed until now.
Researchers looked at weight gain measurements from more than four thousand women at Magee-Womens Hospital in Pittsburgh who were overweight or who were class I, class II, or class III obese and who had uncomplicated pregnancies. Overweight is a body mass index (BMI) of 25 to 29. Class I is a BMI of 30 to 34.9. Class II is a BMI of 35 to 39.9 and Class III is a BMI 40 or more.
Most of these women gained little or no weight until the fifteenth to twentieth week of their pregnancy and then gained weight in a slow manner until the end of their pregnancy.
Using this information, the researchers created charts that obstetricians and other physicians can use to advise women during pregnancy based on the gestational age of the fetus and on the severity of the mother's obesity.
Guiding women to a healthy weight gain during pregnancy can help reduce the risks of these pregnancies. Obesity is an issue during pregnancy because obese women are more likely to develop problems such as gestational diabetes mellitus, high blood pressure, and pre-eclampsia. They are also more likely to need a cesarean section when they birth. Children born to obese mothers are more likely to be premature, stillborn, or to later become overweight themselves.
The study was published in the journal Obesity.