Weight Gain in Pregnancy

One of the most common questions I get asked from pregnant women is how much weight gain is normal?  This is a complex question with a different answer for each individual. Gaining too much weight can lead to gestational diabetes, hypertension, and complications in labour and delivery; plus extra pounds to shred postpartum. Gaining too little weight can lead to preterm labour and a small baby. The normal weight gained in pregnancy is based on pre-pregnancy BMI.  Those that are underweight need to gain more in pregnancy and those that are overweight should gain less.

How do you determine your BMI?  

BMI is Body Mass Index. It is a measurement of body fat based on a person’s height and weight.  There are a couple different ways to find out what your BMI number is including using an online BMI calculator but you can also calculate it with these three steps:

  1. Take your weight in pounds and multiply it by 703.
  2. Take your height in inches and multiply it by your height in inches
  3. Take your answer in step 1 and divide it by your answer in step 2.  

For example,  If you are 5 feet and 6 inches and weigh 150lbs:

  1. (150 × 703) = 105,450
  2. (66 x 66) = 4,356
  3. (105,450 ÷ 4,356) = 24.2 BMI

Now that you have your BMI number lets look at a healthy weight gain for your pregnancy:  

Single baby
Weight gain in pounds
Less than 18.4
28 – 40
18.5 – 24.9
25 – 35
25.0 – 29.9
15 – 25
More than 30
11 – 20
Weight gain in pounds
18.5 – 24.9
37 – 54
25.0 – 29.9
31 – 50
More than 30
25 – 42


But where does all that weight go?

Weight gained in pregnancy is important for the mamas health but also the health of the little baby growing inside.  You need to gain extra weight in pregnancy to have reserves for labour and delivery and breastfeeding plus growing your little baby and its little home inside your belly. Let’s take a closer look at where those extra pounds go.

Baby: 8 pounds (on average)
Placenta: 2-3 pounds
Amniotic Fluid: 2-3 pounds
Breast tissue: 2-3 pounds
Blood Supply: 4 pounds
Stored fat: 5-9 pounds
Larger uterus: 2-5 pounds
Total: 25-35 pounds


Tips to gain the right amount of weight for your range

Eating a healthy and balanced diet will help get your baby the nutrients it needs and fuel your body giving you the goal of healthy weight gain in your pregnancy.  You’ll want to think about having 5 to 6 small meals throughout the day and adding extra protein to each meal while decreased the empty carbohydrates. Easier said than done right? Let’s take a look at what these meals might look like. Empty carbohydrates and food you’ll want to try to avoid would include sugary drinks and sweets like soda pop, chocolate milk and candy. The easiest way to add a little extra protein into your day would be to add peanut butter (if not allergic) to crackers, toast, apples or celery.  Finding a healthy snack on the go can be very difficult, so try to prepare some of these snacks before you leave the house like assorted nuts, cheese and crackers and yogurt. Bring it with you and you can snack wherever and whenever your babe tells you to.

On top of a healthy balanced meals you’ll want to add a little extra activity into your day. Take a look at prenatal classes in your area taught by certified instructors.  These are really fun classes and a great way to meet other mamas-to-be. You can also continue to add walks at the end of your day, swimming and yoga.


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