The US abortion rate is down to its lowest level since the Supreme Court made abortion legal in 1973, and the rate is half of its early 1980s peak.

According to a study issued on Tuesday by the Guttmacher Institute, the abortion rate for American women aged between 15 and 44 is 14.6 per 1,000 in 2014, the last year for which statistics are available.

The figure represents a 14 per cent decline from the 2011 numbers, and less than half of the 1981 rate of 29.4 abortions per 1,000 women of child-bearing age.