why this global boom in twin births?

Twins / twins have never been so numerous in the world, according to a Franco-English study.

Who has never met twins in their life? False or identical twins, these children in pairs are said to be more and more numerous. Indeed, in 30 years, the twinning rate would have exploded! Going between 1980 and 2010 from 9.1 twin deliveries out of 1000 deliveries to 12.

This is what the authors of this study indicate, Gilles Pison, from the National Museum of Natural History and the National Institute for Demographic Studies, Christiaan Monden, from the University of Oxford in the United Kingdom, and Jeroen Smits, from Radboud University in the Netherlands. According to their data, more than 1.6 million pairs of twins are born each year, which represents 3.2 million twin children; or nearly one in 40 babies.

An increase explained by two main factors:

  • "The spread of medically assisted procreation (AMP), which is associated with a high risk of multiple births"
  • "The delay in childbearing, the likelihood of a twin pregnancy increasing with the age of women"

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Thus over three decades, we observe a “twin boom” which nevertheless poses public health problems because of the fragility of the twins and twins. But also in view of the workload doubled for parents. The study indicates that public authorities and medical colleges have been trying, for several years, "To change medical practices so that AMP results in single pregnancies rather than multiple".

Twin births on the rise in wealthy countries where AMP has spread the most so far, the authors say.

More twin births in Africa and Asia

In total, 3.2 million twins are born each year:

  • 1.3 million are born in Africa (650,000 pairs)
  • 1.3 million in Asia (or 650,000 pairs)
  • The rest, about 600,000 children in other continents (or 300,000 pairs)


Eight out of ten pairs of twins are born in Africa or Asia.

A concentration of twins in these continents that the study explains by the number of inhabitants per country. Indeed, Asia gathers 60% of humanity while Africa gathers 17% of humans. In addition, the birth rate and twinning rate are much higher in Africa compared to other continents. However, due to the 30-year twinning boom in Europe and North America, their twinning rates have moved closer to that of Africa, which has not experienced this boom.

The study specifies that the rate of dizygotic twinning (“fraternal twins”) varies from country to country and from period to period. While monozygotic twins (“identical twins”) are born almost in the same number each year: out of 1000 pregnancies, four are twin pregnancies of identical twins.