The US Supreme Court defended abortion rights in a major ruling on Monday by striking down a Louisiana law placing restrictions on doctors who perform the procedure, dealing a blow to anti-abortion advocates.

The 5-4 ruling, with conservative Chief Justice John Roberts joining the four liberal justices in the majority, represented a victory for Shreveport-based abortion provider Hope Medical Group for Women in its challenge to the 2014 law. The measure had required doctors who perform abortions to have a sometimes difficult-to-obtain formal affiliation called “admitting privileges” at a hospital within 30 miles (48 km) of the clinic.