Ideally, if you are under- or overweight before you become pregnant, you will seek advice about reaching the right weight for your height. This is to minimise risks to you and your baby in pregnancy.
Healthy eating and exercise in pregnancy will benefit you and your baby.
On average the total weight gain should be no more than 10-20 kg, with overweight women gaining less weight (no more than 9kg) than underweight women. Weight gain in the early stages of pregnancy may only be minimal but will steadily increase, with the greatest amount being gained in the last 3 months. It is only in the last trimester that calorie intake needs to be increased – by about 200 calories a day.
If your BMI is over 30, you need to try and manage your weight carefully.
Women with a low BMI (<19) should be encouraged to eat a healthy nutritious diet to minimise growth problems in the baby.
All women should take folic acid, ideally from before conception or as soon as pregnancy is diagnosed until the end of the first trimester. If your BMI is over 30, you should take 5mg (prescribed by your GP) instead of the lower dose of 400 micrograms. Vitamin D should also be taken (10 micrograms per day).