Women who have a body mass index (BMI) of 30 or more while pregnant are increasing the health risks involved for their child and themselves.
This is according to recent comments from Jacqui Clinton, who is the health campaigns manager at charity Tommy's.
Ms Clinton said that a BMI of 30 or more is linked with a higher risk of miscarriage, premature birth and stillbirth.
In addition, babies who are born to overweight or obese women are more likely to have a high birth weight and future health problems themselves, such as cardiovascular issues and diabetes.
However, Ms Clinton noted that there is a lack of advice and research concerning the problem.
"There is a need for antenatal care guidelines for weight management in pregnancy and support for health professionals to effectively provide this guidance," she remarked.
The Centre for Maternal and Child Enquiries recently revealed that around five per cent of the UK maternity population is severely obese.