A second federal district court judge has issued a nationwide order to temporarily block the Trump administration from enforcing a new rule that bars taxpayer-funded health-care providers from referring pregnant women for abortion services.

A group of 20 states, the District of Columbia, various chapters of Planned Parenthood, the American Medical Association, and others sued to stop the “gag rule,” which was scheduled to take effect May 3. The U.S. District Court for the District of Oregon said in an April 29 ruling that the challengers are likely to ultimately win on their claim that the rule is illegal, and...