Many doctors believe that where a patient has had several failed IVF cycles, they should be allowed to transfer back more embryos at their discretion. The risk of the latter resulting in multiple births in these difficult cases is negligible, according to articles that have appeared in journals such as Molecular Human Reproduction. Some countries already allow for the latter, but in the UK and Australia for example the number of embryos that can be transferred is limited even in the most difficult cases. Some clinics believe that doctors should have the right to customise the number of embryos they transfer for each patient they treat, rather than blindly following a guideline for the general population that does not take into account an individual’s specific situation.