The Human Fertilisation and Embryology Authority (HFEA) has increasingly wielded its regulatory powers in recent years, as infertility treatments have become more common and diverse. Some of the regulator's decisions have been criticised as arbitrary or inappropriate, using an ethical calculus to coerce parental choice when it is not required. Their latest intervention is controversial, though based upon clinical outcomes.

At present, multiple embryos are implanted in the womb to increase the probability of a successful birth. This has potentially undesirable consequences if the health of the mother or the children is impaired. Studies have monitored infertility treatments and demonstrated these drawbacks.

Half of the mothers of IVF twins give birth prematurely and the babies are below the minimum ideal birth weight of 5lb. They run a much higher risk of dying, lung and heart problems, having cerebral palsy or developmental difficulties and facing chronic conditions as adults. Many spend time in special neonatal care units in hospitals. Mothers who conceive more than one baby after IVF are far likelier to suffer a miscarriage or dangerously high blood pressure than women who have one child naturally.

This should be viewed as additional information that clinicians would take into account when advising their patients and making a diagnosis or a recommendation. If the regulator had drawn attention to these studies and noted that inspectors would wish to see these taken into account during diagnosis, no observer could criticise such diligence. However, we live in New Labour Britain, home of targets and micromanagement:

Shirley Harrison, the HFEA's chair, will this week defend the decision to put medical safety above the rights of childless women to choose how many embryos are transferred. She will cite research showing that having just one embryo implanted does not reduce a woman's chance of conceiving.

Doctors will retain the freedom to use their clinical judgment to decide if a woman rated a 'poor responder' to fertility treatment should still get two embryos. Clinics will be told to reduce the number of multiple births through IVF over time from 25 per cent to somewhere between 5 and 10 per cent.

This is a decision that should rest between the doctor and the patient. If the patient is aware of the risks and responsibilities, they may then take the difficult decision required in this matter. It is not up to HFEA to usurp clinical practice and private judgement in this matter.