Leading fertility specialists have set down recommendations for who should be eligible for free NHS IVF treatment in England and Wales.
Doctors want to ensure all IVF clinics use the same criteria
The British Fertility Society proposes a series of measures, designed to end the existing "postcode lottery", where different clinics and areas operate under different criteria.
One of the new rules suggested by the BFS is that very obese women should not be given fertility treatment.
But how do these proposals differ from what happens now?
Q: Who currently gets IVF on the NHS?
There is no simple answer. There are national guidelines, but individual clinics tend to make decisions based on their own criteria on factors such as age, weight and family background.
The National Institute for health and Clinical Excellence, the NHS drugs and treatment watchdog, recommends women aged between 23 and 39 should receive three free cycles of fertility treatment on the NHS.
WHAT WOULD CHANGE UNDER THE BFS PROPOSALS?
All clinics would operate under the same rules
Very obese women would not be able to get IVF
Women over 40 should not be treated
Couples who have not had children together would be eligible
Having had private IVF would not stop couples having IVF treatment
Same sex couples and single women should be treated in the same way as heterosexual couples
Smokers should not be barred from having IVF
However, the government says only one should be provided.
And a BFS survey found only one in 10 clinics were not giving any free treatment.
NICE also recommends women should "ideally" have a BMI of between 19 and 30 before starting IVF - but clinics use their own rules to decide whether a woman is of a suitable weight.
Being overweight can put both the health of the mother and child at risk through problems such as gestational diabetes and high blood pressure.
Clinics also decide themselves if smoking, having children from a previous relationships or having had private IVF treatment means a woman or a couple is not eligible for NHS treatment.
It is also currently down to individual clinics to decide if lesbian couples and single women should be given IVF.
The Human Fertilisation and Embryology Act 1991 requires clinics to take account of the welfare of the unborn child - including the need for a father.
Again, individual clinics make this decision, although the government has indicated there is probably "not a case" for keeping the clause.
Q: So is the BFS calling for further restrictions?
No. It says its guidelines are designed to ensure the same rules are applied everywhere, and limited resources are spent on those who are most likely to benefit.
Q: What rules does the BFS want introduced?
It says women over 40 should not be given IVF.
The BFS also recommends women who are severely obese - who have a BMI of 36 or more, which is higher than the existing upper BMI limit of 30 - should not get IVF on the NHS.
Underweight women (with a BMI of under 19) and those who are obese (over 30), should be given dietary advice, they added.
It also recommends couples with no children, or with offspring from previous relationships should be eligible.
Those who already have children together should be able to get treatment, if there is local funding available.
Same sex couples and single women should be treated in the same way as heterosexual couples, the BFS says.
And it recommends people who smoke should not be excluded from IVF treatment, but they should be offered advice on how to quit.
Those who have previously had private IVF treatment would be eligible for NHS treatment.
Q: What will happen to these recommendations?
They are the views of senior fertility specialists, but carry no official weight.
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