In a 5-4 vote announced at midnight Eastern Time on Wednesday night, the Supreme Court refused to halt a Texas law banning abortion after six weeks, a point at which most women do not yet know they are pregnant. Chief Justice John Roberts joined the three liberal justices in favor of blocking the law while litigation challenging it proceeds in the lower courts, while the conservative majority opposed doing so in a brief unsigned opinion.

The law had already gone into effect early Wednesday morning when the court declined to issue a ruling on a request for a stay. As a result, clinics in Texas have canceled most appointments, effectively making it all but impossible to obtain an abortion in the state.