What is it?

During pregnancy, some weight gain is normal. How much weight you gain depends on what you weighed before you got pregnant and whether you are having a single pregnancy or twins (or even triplets).

Your GP uses your body mass index (BMI) to determine if your weight is within a healthy range. You calculate your BMI by dividing your weight by your height. A healthy BMI is between 18.5 and 24.9. During pregnancy, your GP uses your BMI to determine:

If you are in a healthy weight range before pregnancy and

How much weight you can expect to gain

If you were in the healthy weight range before you got pregnant, you can expect to gain 11.5 to 16 kilograms during your pregnancy. If you were underweight, you may need to gain more. If you were overweight, you may need to gain less.

Your medical team will tell you more about how to maintain a healthy weight and how much weight you can expect to gain during each month of your pregnancy.