Cymru oedd y wlad gyntaf yn y DU i newid y system rhoi organau drwy gyflwyno system feddal o optio allan yn 2015. Caiff pobl 18 oed neu hŷn sydd wedi byw yng Nghymru am fwy na deuddeng mis ac sy’n marw yng Nghymru eu hystyried bellach fel pe baent wedi rhoi cydsyniad i roi organau, oni bai eu bod wedi optio allan. Mae hyn yn cael ei alw’n gydsyniad tybiedig.
Wales became the first part of the UK to change the organ donation system when it introduced a soft opt-out system in 2015. People aged 18 and over who have lived in Wales for more than 12 months and who die in Wales will now be regarded as having consented to organ donation unless they have opted out. This is called deemed consent.