This depends on your body mass index (BMI) before you conceived.
If your pre-pregnancy weight was in the healthy range (a BMI of 18.5 to 24.9), you should gain between 11.3 and 15.9 kilograms, gaining 0.9 to 2.3 kilograms in the first trimester and a little less than half a kilo per week for the rest of your pregnancy for the optimal growth of your baby.
If you were underweight at conception (a BMI below 18.5), you should gain 12.5 to 18 kilograms. If you were overweight (a BMI of 25 to 29.9), you should gain 6.8 to 11.3 kilograms. If you were obese (a BMI of 30 or higher), you should gain no more than 6.8 kilograms. If you’re having twins you should gain about 16 to 20.5 kilograms. If you want to make sure you’re OK, tak to your doctor about how much you should gain each month.
Calculate your BMI:
Take your length in meters (for example 1.60 meters)
Take the square of your lenght (for example 1.60 x 1.60= 2.56)
Take your weight in kilograms (for example 55 kilograms)
Divide your weight through the square of your length (55:2.56=21.48)
Your BMI is 21.48
