Bridgette Dunlap, a Fordham University law student, knew that the school’s health plan had to pay for birth control pills, in keeping with New York state law. What she did not find out until she was in an examining room, “in the paper dress,” was that the student health service — in keeping with Roman Catholic tenets — would simply refuse to prescribe them.

As a result, students have had to go to Planned Parenthood or private doctors to get prescriptions. Some, unable to afford the doctor visits, gave up birth control pills entirely. In November, Ms. Dunlap, 31, who was raised a Catholic and was educated at parochial schools, organized a one-day, off-campus clinic staffed by volunteer doctors who wrote prescriptions for dozens of women.

Many Catholic colleges decline to prescribe or cover birth control, citing religious reasons. Now they are under pressure to change. This month the Obama administration, citing the medical case for birth control, made a politically charged decision that the new health care law requires insurance plans at Catholic institutions to cover birth control without co-payments for employees, and that may be extended to students. But Catholic organizations are resisting the rule, saying it would force them to violate their beliefs and finance behavior that betrays Catholic teachings.

“We can’t just lie down and die and let religious freedom go,” said Sister Mary Ann Walsh, a spokeswoman for the United States Conference of Catholic Bishops.