Northern Ireland is the only region in the United Kingdom where the Abortion Act (1967), which established legal abortion, does not apply and a pregnancy can currently only be terminated when it poses a direct threat to a mother's life.
Rape, incest and foetal abnormalities do not allow an abortion in Northern Ireland.
A Pastoral Reflection by the Catholic Bishops of Northern Ireland published ahead of next week's Stormont vote said: "The next Assembly term will see further pressures being brought to bear on politicians to introduce abortion to Northern Ireland.
"The moral issue here is not whether what is proposed is abortion 'on demand' or some form of so-called 'limited' abortion.
"Abortion is always the deliberate and intentional taking of an innocent, vulnerable human life, and a direct breach of the commandment 'Thou shalt not kill'.
"The medical prognosis for the life of a child in the womb, or the extent of that child's disabilities, is no more morally relevant than it is when considering an adult who faces the diagnosis of a life-limiting condition.
"This is why the social and moral teaching of the Church is clear, that it is never morally acceptable to support any policy that undermines the sacred inviolability of the right to life of an innocent person in any circumstances.
"A society worthy of our dignity as human persons, is one that calls us to respond from our noble capacity as human beings to care for and support someone in crisis, thereby valuing equally the life of a mother and her unborn child, rather than diminish our humanity by destroying another human life."
The statement also said: "Voting for those who will govern our society is a moral act.
"Each vote cast, or not cast, potentially influences the values that will shape future law and policy, by endorsing the values and policies of a particular candidate or party.
"In recent years, it is striking how many Catholics and others in Northern Ireland have indicated to us, and to many priests, that they find it increasingly difficult to find a political party for whom they can vote in good conscience."
The 6,000 word document also expressed opposition to same-sex marriage and contained a call for the next Programme for Government to tackle childhood poverty, ensuring no child starts the day without a nutritional breakfast.