Abortion rates have declined to a historic low over the last 25 years in developed countries but in poorer nations rates have remained unchanged, a new study has found, highlighting the urgent need for better access to modern contraception in these regions.
The new global and regional estimates of abortion incidence from the Guttmacher Institute in the US and World Health Organisation (WHO) also suggest that restrictive abortion laws do not limit the number of abortions.
"In developed countries, the continued fall in abortion rates is largely due to increased use of modern contraception that has given women greater control over the timing and number of children they want," said Gilda Sedgh from the Guttmacher Institute.
"In developing countries, however, family planning services do not seem to be keeping up with the increasing desire for smaller families," Sedgh said.
"More than 80 per cent of unintended pregnancies are experienced by women with an unmet need for modern methods of contraception, and many unwanted pregnancies end in abortion," she said.
The researchers used a statistical model to estimate levels and trends in abortion incidence for all major world regions and subregions from 1990 to 2014.
Between 1990 and 2014, the developed world's annual abortion rate per 1,000 women of childbearing age (15-44 years) dropped from 46 to 27, mainly as a result of the rate in Eastern Europe more than halving (88 per 1,000 women to 42) as modern contraceptive methods became more widely available.
However, in the developing world the abortion rate has remained virtually unchanged, declining from 39 to just 37. Worldwide, on average 56 million abortions took place each year in 2010-2014.
Over the last 25 years, Eastern Europe has seen the biggest drop in abortion rates (88 to 42 per 1,000 women), but rates also fell in Southern Europe (38 to 26), Northern Europe (22 to 18), and North America (25 to 17).
The overall abortion rate in Africa, where the vast majority of abortions are illegal, remained virtually unchanged - 33 abortions per 1,000 women in 1990-94 to 34 per 1,000 in 2014.
The estimated worldwide proportion of pregnancies that end in abortion has been fairly stable over time, with the world average in 2010-14 being one in four (25 per cent).
In developed countries, abortion has declined as a proportion of all pregnancies from 39 per cent in 1990-94 to 28 per cent in 2010-14, whereas in developing countries it increased from 21 per cent of pregnancies in 1990-94 to 24 per cent in 2010-14.
The study was published in The Lancet journal.
