That recommendation would draw a racial discrimination suit before the ink on it dried if someone made it in the States.
There wouldn't be a problem as long as it is framed as a health issue. BMI of 31 is serious fatass and unhealthy.
The difference is that IVF doesn't work on very obese women so why should the money and time be spent, particularly under a government plan, for treating these women. It would be more effective for women to determine what the underlying reason is for their massive obesity and correct that, then let fertility take its natural result. Also, don't forget that most men deny fertility treatment to very obese women, too. < / sarc>
This is one more example of how the nanny state is going to force us to do things "for our own good".