Some students have criticised graphic abortion images being displayed on a main road after a pro-choice row was sparked at Cardiff University.
Anti-abortion campaigners protested outside the main building after the students' union adopted a pro-choice stance.
The protesters said the move followed a "disturbing trend".
But the students' union said it would not censor the rights of students who hold different views.
The protests were held on Saturday and Wednesday after 800 members of student societies took part in a meeting where the decision was made to advocate the right of a woman to choose whether or not she would have an abortion. A similar motion was rejected in 2014.
It prompted the Centre for Bio-Ethical Reform UK (CBR), which is not linked to any societies involved, to put up the large graphic images and ask passers-by if they thought the pictures were children.
Pro-choice counter-protesters demonstrated alongside on Wednesday, some blocking the demonstrators' images and chanting "Cardiff Uni is pro-choice".
Some students also criticised the graphic images being displayed for public view.
Margot Roeth said "regardless of your personal views on abortion, it's important to note that these images were displayed in public, where young children could easily walk past and see".
The vote, which took place on 21 November, passed with a large majority.
Wellbeing Officer for the feminist society, Isadora Sinha, 22, said she proposed the motion because it made sure that "all students, no matter their views and choices, are accepted and supported".
She added that the protests were an "external anti-choice response to a democratic student union matter".
University chaplain, Father Sebastian Jones, had warned that the decision would "violate Cardiff University's principle of inclusivity and diversity which to date has extended to all people of faith". He urged the Catholic society to withdraw their membership from the students' union following the decision as it would "risk incurring excommunication from the Catholic Church".
The anti-abortion society, Cardiff Students for Life, was reintroduced to the union after a few years of being inactive and said that they planned to protest outside clinics as part of their "40 days of life".
Catholic member Luke Doherty said the pro-choice stance would now restrict what "students can contribute to the debate on abortion" and highlighted that "freedom of faith is no longer a protected characteristic at Cardiff University".
A Cardiff University Students' Union spokeswoman said protestors who claimed the decision would restrict students were using a "false narrative being promoted by individuals and organisations who are seeking to undermine the freedom of expression of students".
The students' union, which is independent of the university, said they had met with some of the societies who were affected and reassured them about their future at the union.