Question to the Department of Health and Social Care:

To ask the Secretary of State for Health, what estimate he has made of the number of human eggs that would be required annually for (a) pro-nuclear transfer and (b) maternal spindle transfer should the NHS provide mitochondrial transfer.

The Human Fertilisation and Embryology Authority (HFEA) has advised that no estimate has been made of the number of human eggs that would be required annually for the maternal spindle transfer (MST) and pronuclear transfer (PNT) mitochondrial donation techniques. The number of eggs required will depend on the number of clinics who are licensed to perform the techniques, the number of patients they treat and the number of eggs required in the treatment of each patient.

The independent expert panel convened by the HFEA published its fourth review into the safety and efficacy of mitochondrial donation on 30 November 2016. The expert panel made a number of recommendations on the potential avenues for laboratory research around mitochondrial donation techniques, which the HFEA supports.

In terms of any subsequent treatments which may be offered, Regulations made under the Human Fertilisation and Embryology Act 1990, as amended, only permit the MST and PNT techniques to be used in treatment. Further research may lead to refinement of these techniques but the clinical use of any alternative mitochondrial donation techniques would require new legislation.