The Human Fertilisation and Embryology Authority, responsible for regulating the sector, said it was concerned about the increasing marketisation of add-ons but admitted it has limited powers to intervene.
Professor Carl Heneghan, Director of Oxford’s Centre for Evidence Based Medicine, said “Some of these treatments are of no benefit to you whatsoever and some of them are harmful.
“I can’t understand how this has been allowed to happen in the UK.”
Approximately one in seven couples in Britain have trouble conceiving, with increasing numbers of people choosing to delay trying for a family until they are older a contributing factor.
Official guidelines stipulate that the NHS should offer three full rounds of IVF to women under 40 who have not conceived after two years of regular intercourse, although the reality is a postcode lottery and numerous areas only offer one.
The new study, published in the British Medical Journal, analysed claims made across on 74 UK fertility centres’ websites.
Of 276 claims relating to the benefits of fertility interventions, just 16 were accompanied by references citing corroborating scientific research, of which only five were rigorous systematic reviews.
Add-on treatments include blastocyst culture, the practice of waiting longer to transfer embryos from a laboratory to the uterus in the hope that they will be healthier and lead to a higher chance of pregnancy, which can cost around £800.
Assisted hatching, creating a hole in the outer layer of an embryo to improve its quality, which is offered for around £450, is also offered by private clinics.
Another commonly offered add-on which aims to test embryos for abnormalities, Preimplantation Genetic Screening, has in fact been the subject of papers which suggest it lowers birth rates.