Gwnaed y newid i’r blwch rhwng profion sgrinio yn unol â chyngor annibynnol ac arbenigol Pwyllgor Sgrinio Cenedlaethol y DU. Gwnaeth y Pwyllgor hwnnw yr argymhelliad ar gyfer ymestyn y bwlch rhwng profion ym mis Chwefror 2019 ar ôl cynnal ymgynghoriad cyhoeddus. Felly, dyma'r argymhelliad cyfredol ar gyfer y DU sy'n seiliedig ar dystiolaeth. Cafodd y newid ei roi ar waith yn yr Alban ym mis Mawrth 2020. Mae'r newid yn cael ei wneud yng Nghymru bellach gan fod y dystiolaeth wedi dangos ei bod yn ddiogel i ymestyn y bwlch rhwng y profion sgrinio ar sail y ffaith bod y prawf sgrinio’n fwy effeithiol.
The change to the screening interval has been made in line with the independent, expert advice of the UK National Screening Committee, which made the recommendation for the interval change in February 2019 after undertaking a public consultation. This is therefore the current evidence-based recommendation at a UK level. It was implemented in Scotland in March 2020. The change is now being made in Wales as the evidence has shown it is safe to extend the screening interval due to the improved test.