In a setback for women facing a particularly vulnerable moment in their lives, a federal judge has temporarily barred New York City from enforcing a new law that would require so-called crisis pregnancy centers masquerading as licensed medical facilities to disclose basic facts about their services.

These centers, run by abortion opponents, have sprung up in many places around the country. They typically draw clients with advertisements that appear to promise neutral abortion counseling. Staff members in medical attire collect information and perform pregnancy tests and sonograms and try to convince women not to have an abortion. Women who share personal information are also unaware that the centers are not covered by medical confidentiality rules.

The New York City law would require these centers to disclose in ads and waiting-room signs whether they have a licensed medical provider supervising services and whether they make referrals for prenatal care, abortion and emergency contraception. Client information they collect would be subject to confidentiality rules.

The decision by Judge William Pauley III of Federal District Court in Manhattan acknowledges the city’s interest in preventing deception related to time-sensitive reproductive health care. The judge still granted a preliminary injunction, mistakenly perceiving a violation of free expression in the law’s modest consumer protections.