The rate of twin births worldwide, relative to all births, has increased by a third since the 1980s, due to greater use of medically assisted procreation (MAP), and an increase in the average age of mothers, indicates a demographic study published on Friday, March 12.
"The rate of twin births has never been higher in the world,"
conclude the authors of the study, published in the scientific journal
Human Reproduction
.
In thirty years, this rate has gone from 9.1 twin births per 1,000 births in total in the 1980s to 12 per 1,000 in the 2010s, so much so that today “almost one in 40 babies is a twin. ".
Read also: The exhausting mystery of the twins
"This
" boom twin "
poses a public health problem because they are fragile children who require more care and have a higher mortality than the others, not to mention the difficulties for parents to take care of two babies. at the same time ”
, observe the authors, Gilles Pison (National Museum of Natural History and National Institute of Demographic Studies, Paris, France), Christiaan Monden (University of Oxford, United Kingdom), and Jeroen Smits (Radboud University , Nijmegen, The Netherlands).
Mountain peak
However,
"we may have reached a peak in terms of twinning rates"
, according to the authors, who observe that
"for several years"
, doctors have been trying to change their practices so that assisted reproduction techniques are successful.
"To single pregnancies rather than multiple"
.
It should be noted that only the births of "fraternal twins" (dizygotes) increased, the proportion of "identical twins" (monozygotes) having remained stable, at 4 pregnancies in 1,000.
To read also: Having twins, the supreme anguish of parents
Of the 3.2 million twins who are born each year in the world, about 40% are born in Asia (which brings together 60% of humanity) and 40% in Africa: this continent is home to only 17% of the world population, but its birth rate is
"between double and triple that of other continents"
, and its twinning rate is also the highest in the world.
In 30 years, the twinning rates observed on other continents have, however, approached African rates, which have not changed.
