What is normal weight gain during pregnancy?


Regardless of your starting weight, not only will you gain weight during pregnancy, but you should. Finding your magic number is key: Too much or too little weight gain can lead to negative health effects for both mother and baby.

Anne-Marie Sinay, MD, an obstetrician / gynecologist at Ohio State Wexner Medical Center, explains the ideal weight gain, the risks of putting on too many pounds and if it’s ever safe to lose weight during pregnancy.

What is the right amount of weight to gain?

Dr. Sinay explains proper weight gain should be put into relation with a woman’s pre-pregnancy Body Mass Index (BMI).

BMI is the measurement of your weight for your body surface area. It’s considered a reliable indicator of body fat for most people. A BMI less than 18.5 is underweight. Below 25 is normal. A BMI of 25 through 29.9 is overweight, and 30 or higher is considered obese. Figure out your BMI.

Pre-Pregnancy BMI Recommended weight gain during pregnancy
< 18.5 30 - 40 pounds
18.5 - 24.9 25 - 35 pounds
25 - 29.9 15 - 25 pounds
>30 10 - 20 pounds

Recommended weight gain by trimester

In the first trimester, there isn’t a need to increase caloric intake so weight gain should be minimal – less than five pounds total, according to Dr. Sinay.

In the second and third trimesters, weight gain should increase to an average of about one pound per week for normal weight women.

“I really stress to my patients this is just an average. Overall weight gain is more important than week-to-week variability,” says Dr. Sinay.

What are the risks of gaining too much weight?

Too much weight gain can increase a woman’s risk of developing gestational diabetes or having a larger baby. In turn, a larger baby increases the risk of complications during a vaginal delivery, and can even alter birth plans to a cesarean delivery.

Excessive weight gain also increases the risk of developing hypertension in pregnancy.

Lastly, women who gain too much weight in pregnancy are also more likely to retain that weight long term.

What are the risks of not gaining enough weight?

Too little weight gain can increase a woman’s risk of having a low birth weight baby and preterm labor – defined as a labor occurring before the 37th week of 40-week pregnancy.

Health concerns with delivering a baby prematurely, including low birth weight, underdeveloped organs and breathing difficulties.

Is it ever safe to lose weight during pregnancy?

Intentionally losing weight while pregnant, even for women who are obese, is a controversial and debatable topic, says Dr. Sinay.

“I generally discourage trying to lose weight while pregnant,” she explains.

“Perhaps it is possible there may be some benefit in modest weight loss – 5 to 10 pounds – for women with a BMI over 40, but this hasn’t been studied enough to be able to recommend it enthusiastically.”

As an alternative, Dr. Sinay advises patients the best way to avoid gaining too much weight during pregnancy is to simply eat a well-balanced, healthy diet and exercise regularly. 
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