How Much Weight Should You Gain During Pregnancy?

Pregnant or not, body weight tends to be a loaded topic for women. So it's no wonder moms-to-be have concerns about their changing weight and shape.

"When a woman becomes pregnant, the extent to which her body changes is amazing. Physiologically, she's almost a completely different human being," says Jeffrey Smith, M.D., obstetrician/gynecologist at Henry Ford Health. "Her blood volume dramatically increases. Her respiratory and cardiovascular systems operate differently and many nutrients once solely allocated to her own muscles, bones and tissues may now be shared the baby."

Pregnancy Weight Gain Explained

Most women expect to gain some weight when they become pregnant, but the specifics of when and how much they'll gain is largely a mystery. While the American College of Obstetricians and Gynecologists (ACOG) provides basic pregnancy weight gain guidelines based on a woman's starting body mass index, or BMI, every pregnancy is unique.

"More important than the number on the scale is how mom and baby are navigating the pregnancy," Dr. Smith says.

So how do you assess where you're at? Take note of these five tenets of safe and appropriate weight gain during pregnancy:

1. Pay attention to your pre-pregnancy weight: Weight gain recommendations vary depending on how much you weigh at the start of your pregnancy. "If your BMI falls within a healthy range — 18 to 25 — a weight gain of 25 to 35 pounds is appropriate," says Dr. Smith. "If, however, your starting weight falls in an overweight or obese category — a BMI over 25 — you may only need to gain 11 to 25 pounds."
2. Understand where the added weight is going: The weight you gain during pregnancy isn't just baby weight. Increased blood volume (up to 4 pounds), growing uterine and breast tissue (another 3 to 5 pounds), the weight of the placenta (up to 2 pounds) and the fluids baby makes (another pound or two) add up. Those increases in fluid and tissue volumes are largely responsible for about one pound of weight gain each week during the second and third trimesters.
3. Be aware of the risks: Gaining too much or too little weight during pregnancy may increase your risk of developing certain complications. Too little weight gain can result from excessive nausea and vomiting and can lead to low birth weight, nutrient deficiencies and other negative outcomes. Too much weight gain can increase your risk of gestational diabetes, high blood pressure and a larger infant at birth. "It's important to discuss your individual risk of developing complications with your provider," Dr. Smith says.
4. Stay active: While pregnancy may not be the best time to train for your first marathon, it is a time when you should be physically active. If you ran five miles a day before you got pregnant, you may usually continue your exercise routine while you're carrying a baby. Setting fitness goals is appropriate, too. The key is listening to your body and making sure you engage in safe activities that are healthy for both you and your growing baby.
5. Eat a healthy diet: Between nausea, fatigue and food aversion, eating a well-balanced diet can be a challenge during the first trimester. That's par for the course, according to Dr. Smith. But once you enter the second trimester and beyond, it's important to eat a wide variety of nutrient-rich foods. Not sure where to start? Ask your provider to refer you to a dietitian or nutritionist to help ensure you get the nutrients you need most during pregnancy and while breastfeeding.

A Healthier Pregnancy

The best time to get a handle on pregnancy-related weight concerns is before you're expecting a baby. If you can adopt a healthy diet and lifestyle before conception, it will be easier for you to stay on track when you're pregnant. That rule remains the same whether this is your first or fifth pregnancy, even though every pregnancy is different.

"Pregnancy can change your health status overnight," Dr. Smith says. "You're at greater risk of developing diabetes and blood clots. While the amount of weight you gain plays a role in some of those negative health outcomes, it's not the most important thing to focus on."

What really sets the stage for healthy moms and babies is establishing prenatal care, opening a dialogue with your provider and not being afraid to ask difficult questions about health and nutrition. Getting sufficient calories and paying attention to nutrition is not only important for pregnancy weight gain, it's also critical for meeting your baby's nutrients needs — and your own!

To find an obstetrician or gynecologist at Henry Ford, visit henryford.com or call 1-800-HENRYFORD (436-7936).

Dr. Jeffrey Smith is a obstetrician and gynecologist who sees patients at Henry Ford Medical Center - Livonia.