Doctors in Canada will consider a policy to withhold IVF to obese women at a national meeting of fertility experts this week.

Some doctors have called for the ban, arguing that women with a BMI over 35 face increased health risks when trying to conceive through IVF. But opponents of the ban have said the move could amount to discrimination. Dr Arthur Leader, co-founder of the Ottawa Fertility Centre, believes that the risk of medical complications for very obese women following IVF is too high.

'[We] have agreed that the risks of the procedure, plus the risks of the pregnancy, plus the risks of an abnormal baby in obese women doesn't justify subjecting the women to IVF until they've lost enough weight to bring their body mass index (BMI) below 35', said Dr Leader.

'We've had many angry patients say to us, 'This is discriminatory' and I say, 'Yes, it is'. But I still won't do it', he continued. 'A patient doesn't have the right to make a choice that's going to be harmful to them'.

The Ottawa Fertility Centre says its doctors agreed to withhold IVF to women with a BMI greater than 35 six years ago because of health risks to the mother and child. A BMI of 30 is normally considered the threshold for clinical obesity.

There are conflicting views as to whether the risks, which include gestational diabetes, pre-eclampsia and miscarriage, are actually higher for obese women. Studies can be found in support of either side of the argument. However, with obesity rates on the rise, some doctors consider the decision to refuse treatment to obese women to be unacceptable and discriminatory.

'You'd be denying half the reproductive population from gaining access to fertility treatment', said Dr Anthony Cheung, a fertility expert at the University of British Columbia. 'These people already know they have a problem – are you going to make it worse, add to feelings of social injustice, low self-worth, depression?'

'We don't say, 'Oh sorry you smoke, so we can't treat you – it could result in pre-eclampsia, or small babies'', he added.

The debate will be hosted by the Canadian Fertility and Andrology Society, which recommends standards for the country's fertility practice. The British Fertility Society and their counterparts in Sweden and New Zealand already recommend withholding IVF for obese women.

'We respect that people have the right to make their own choices but we also have a duty of care to do no harm', said Dr Leader.