Congratulations — you’re pregnant! Along with what to put on the baby registry, how to set up the nursery, and where to go for preschool (just kidding — it’s a bit too early for that!), many people want to know how much weight they can expect to gain over the next 9 months.
While the majority of the pounds will make their appearance during the second and third trimester, there’s some initial weight gain that will happen in the first 12 weeks of pregnancy. In fact, on average, people gain 1 to 4 pounds in the first trimester — but it can vary. Let’s take a look at the factors involved.
“This is one of the most asked questions for patients during their much anticipated first obstetrical visit with their doctor,” says Jamie Lipeles, MD, DO, OB-GYN and founder of Marina OB/GYN.
Despite what you might have heard, you don’t gain too much weight in the first trimester, with the standard recommendation being 1 to 4 pounds. And unlike the second and third trimester (when body mass index, or BMI, may be more of a factor), Lipeles says the weight gain during the first 12 weeks is pretty much the same for all body types.
And if you’re pregnant with twins, Lipeles says the same guidelines apply to weight gain during the first trimester. However, this can change during the second and third trimesters, as twin pregnancies typically result in greater weight gain.
That said, there are occasions when your doctor may have a different recommendation for the first 12 weeks. “For patients with a BMI of more than 35, we often encourage them to maintain their weight for the entire first trimester,” says G. Thomas Ruiz, MD, OB-GYN at MemorialCare Orange Coast Medical Center.
Spending more time tightening your pants than loosening them in the first trimester? You might be wondering if losing or maintaining your weight is a red flag.
The good news? Not gaining any weight during the first trimester doesn’t mean anything’s wrong. In fact, losing a few pounds in the first half of your pregnancy is a common occurrence (hello, morning sickness and food aversions!).
If you haven’t experienced morning sickness, consider yourself lucky. Feeling nauseous and experiencing occasional vomiting at any time of the day may cause you to maintain your weight or lose a few pounds. Fortunately, this typically subsides in the second and third trimester.
Pursing your lips at the sight of your favorite plate of scrambled eggs and bacon is also common in the first trimester. “I often joke with my patients and tell them that they might have food aversions in the first trimester, but then will overcompensate in the second and third trimester by having food cravings out of character for them outside of pregnancy,” says Lipeles.
If you’re experiencing vomiting or food aversions, make sure to share this information with your OB-GYN at your routine visits. It’s important to keep them in the loop, especially if you’re losing weight. “Weight loss means the body is in a breakdown mode and is stressed, which leads to a deficiency in nutrients,” says Felice Gersh, MD, an OB-GYN at Integrative Medical Group of Irvin, where she’s the founder and director.
“Fortunately, an embryo can still acquire the nutrients needed for its development and growth — the mom, however, can lose important lean body mass and supportive fat,” adds Gersh.
And you do need to be cautious of experiencing notable weight loss.
One of the most common causes of significant weight loss is hyperemesis gravidarum, which is the most severe form of nausea and vomiting during pregnancy. This occurs in about 3 percent of pregnancies and typically requires treatment.
One of the perks of being pregnant is being able to ditch the diet mentality more easily. (We should likely all ditch it, permanently.) That said, it’s important to be aware of your weight and how it compares to the weight gain recommendations, as gaining too much weight comes with risks to both you and baby, including:
- Weight gain in baby: When mom gains weight, baby is likely to gain more than usual in the womb. This can result in a larger baby at birth.
- Difficult delivery: With a significant weight gain, Lipeles says the anatomy of the birth canal is altered, yielding a more difficult and dangerous vaginal delivery.
- Higher risk of gestational diabetes: Gaining too much weight, especially early on in your pregnancy, can be an early sign of gestational diabetes. If you gain more than recommended in the first trimester, Lipeles says not to be surprised if your doctor gives you a glucose test prior to the standard 27- to 29-week range.
Despite the old saying “you’re eating for two,” the first trimester isn’t the time to load up on calories. In fact, unless your doctor has told you otherwise, you should maintain your pre-pregnancy intake.
However, as your pregnancy progresses, a gradual increase in calories is recommended. The Academy of Nutrition and Dietetics suggests a range of 2,200 to 2,900 calories a day, depending on your BMI prior to pregnancy. This equates to the following increase per trimester (use your pre-pregnancy intake as a baseline):
- First trimester: no additional calories
- Second trimester: eat an additional 340 calories per day
- Third trimester: eat an additional 450 calories per day
Most of us begin this journey with high hopes of eating healthily, exercising regularly, and avoiding anything with a shelf life longer than our pregnancy.
But then, life happens.
Between managing work, other children, social obligations, and all those trips to the restroom, finding the time — and energy — to maintain your pre-pregnancy exercise schedule or whip up a celebrity-inspired meal is sometimes a real challenge. The good news? You don’t have to get it right every day to grow a healthy human being.
So, what should you aim for? If you’re up for it, keep doing what you were doing before getting pregnant, as long as it doesn’t involve hanging upside down from a trapeze bar. Physical activities that are excellent choices during the first trimester include:
- walking
- swimming
- jogging
- indoor cycling
- resistance training
- yoga
Set a goal to exercise most days of the week, or at least 150 minutes each week. The important thing is to stick to what you know. This is not the time to take up marathon training, especially if you’ve never run before.
As far as nutrition, aim to eat a balanced diet with a variety of foods. This includes:
- whole grains
- fruit
- vegetables
- lean protein
- healthy fats
- low fat dairy products like milk and yogurt
Since your body doesn’t require additional calories during the first trimester, eating as you usually would — provided it’s nutritious — is the goal.
While no two pregnancies are the same, there are some general guidelines to follow when it comes to gaining weight throughout all three trimesters. The American College of Obstetricians and Gynecologists (ACOG), along with the Institute of Medicine (IOM), categorizes weight gain based on your weight at your first appointment.
In general, the range for all 9 months is anywhere between 11 and 40 pounds. Those with more weight or obesity may need to gain less, whereas those with less weight may need to gain more. More specifically, the ACOG and IOM recommend the following ranges:
- BMI less than 18.5: approximately 28–40 pounds
- BMI of 18.5–24.9: approximately 25–35 pounds
- BMI of 25–29.9: approximately 15–25 pounds
- BMI 30 and greater: approximately 11–20 pounds
For twin pregnancies, the IOM recommends a total weight gain of 37 to 54 pounds.
To get a better idea of how many people stay within this range, the
Ideally, you’ll find a doctor you can trust to answer some seriously awkward questions. But even if this is your first go-around with your OB-GYN, leaning on them for knowledge and support is key to easing anxiety during pregnancy.
Since weight measurements are a part of every prenatal visit, each appointment is an opportunity to address any questions or concerns, especially since your OB is tracking a number of things, including weight changes.
