Pregnant women could be banned from entering the United States of America, under plans being considered by President Donald Trump after the Supreme Court judgment that struck down his ban on birthright citizenship.

The potential ban would mark a renewed attempt to restrict birthright citizenship, a practice the Trump administration said allows foreigners to travel to the US late in pregnancy to secure citizenship for their children.

While the practice exists, experts say it is a tiny fraction of overall births. Though the US government does not track the number of babies born to foreign visitors, but estimates suggest the figure could be between 20,000 and 26,000 per year.