In the stark landscape of the American south-west, a billboard on the New Mexico border welcoming drivers on the long, straight highway from Arizona has an equally stark message. “Welcome to New Mexico where your reproductive rights are protected,” it announces. “Abortion care is legal.”

That right is also increasingly rare in this area of the United States. Two of the four states bordering New Mexico – Texas and Oklahoma – have effectively banned abortion and the Arizona state legislature has only just overturned the reimposition of an 1864 law preventing abortion in almost all circumstances.