Complex sentence: A constitutional amendment to legalise abortion in the first trimester was narrowly defeated in a popular referendum in 1977; but in 1978 and 1985, initiatives for constitutional amendments aiming at making abortion harder to obtain were also defeated by a wide margin at the ballot.
Split into simpler sentences: A constitutional amendment to legalise abortion in the first trimester was narrowly defeated in a popular referendum in 1977. However, in 1978 and 1985, initiatives for constitutional amendments aiming at making abortion harder to obtain were also defeated by a wide margin at the ballot.