Young women could be at a greater risk of developing cervical cancer because of a policy change meaning that they are now only invited for tests at 25 instead of 20.
The policy change, which came into effect in 2004, means that changes in the cells of the cervix, which can be a precursor to cancer, may not be picked up in the early stages before cancer develops.
In a letter to the British Medical Journal (BMJ), consultant pathologists expressed their concern and said that more women are now having sex at a younger age and may therefore experience serious cell changes between the ages of 20 and 24.
"Prevalence of carcinoma in situ (CIN3) has increased in women aged 20 to 24, which is consistent with more women in recent birth cohorts starting sexual activity in their mid-teens," wrote Amanda Herbert from Guy's and St Thomas' NHS Foundation Trust in London and John Smith from the Royal Hallamshire Hospital in Sheffield.
"The new policy will add more than 3,000 women with untreated CIN3 to the larger numbers failing to accept their invitations later on."
When the policy was initially announced, it was claimed that cervical cancer is rare in women under the age of 25 and that screening during very early adulthood caused more harm than good.
However, the authors warn that this message is unlikely to encourage women to accept their invitations for screening from 25 and could have contributed to the recent fall in cervical screening coverage.
Independent advice on private healthcare