The risk of complications, such as hypertension and diabetes that can affect the unborn baby, increases in women with a higher BMI. Underweight mothers are more prone to a reduction in the amount of amniotic liquid and newborns are more likely to be underweight if their mother is.
Obese and underweight women are more likely to be re-admitted to hospital with problems after birth than women with a normal BMI.
Talk to your GP or nutritionist to ensure you reach a healthy weight before getting pregnant and make sure you get started on the right track towards a healthy pregnancy.