In 2018, he was one of 25 TDs to vote against the Thirty-sixth Amendment of the Constitution Bill, which proposed to replace the protection of the life of the unborn inserted by the Eighth Amendment with a provision allowing the termination of pregnancy to be regulated by law. This amendment was approved in a referendum in May 2018 by 66.4%, including 65.9% in his constituency. Ó Cuív was one of 15 TDs to vote against the Health (Regulation of Termination of Pregnancy) Bill, which became law at the end of 2018. Following the 2020 general election, he said that he was 'completely against' Fianna Fail going into coalition with Fine Gael and the Green Party. He later went on to publicly doubt the programme for government.