Changes to the way women are screened for cervical cancer come into effect on Sunday with the starting age increasing from 20 to 25. Women over 50 will be tested every five years instead of every three years.
There's a warning lives could be put at risk because of changes to the age women in Wales will be called for a smear test. Currently all women between 20 and 64 are invited for a screening but from Sunday the starting age will rise to 25.
The Welsh Government say the decisions are based on expert advice, but not everyone's convinced as our health reporter Rob Osborne has been finding out.
The changes are based on recommendations from the UK National Screening Committee, following expert advice and consultation and are supported by Wales Screening Committee.
Evidence shows that screening women aged 20-24 causes more harm than good. The same research provides evidence that screening women aged 50-64 on a 5 yearly basis offers the same protection as being screened every three years.
These policy changes, which were announced by Welsh Government in January 2013, bring Wales in line with cervical screening programmes in England and Northern Ireland, with Scotland planning to introduce these changes by 2015.
Concerns are being raised over changes to the cervical screening programme in Wales which come into effect this weekend.
From Sunday, the starting age for woman to have smear tests will rise from 20 to 25 and women over 50, who are currently tested every three years, will only be called for a test every five years.
Lindsay Whittle, Plaid AM for South Wales East, says he has raised the issued with Health Minister Mark Drakeford AM, after he was contacted by two women affected by cervical cancer.
He said: "I have grave concerns that this decision will lead to more cases of cervical cancer laying undetected for longer. I have two constituents who are examples of the importance of early detection which with cancer we are always told is crucial.
"Wales has been first on issues like free concessionary bus passes, charges on carrier bags and free prescriptions. But i don't like the idea of being first on an issue which could affect women's health and a huge chunk of the Welsh population."