The number of twins being born is at its highest level ever due to a rise in the use of in vitro fertilization and other assisted reproduction techniques, according to the first global study on human twinning.
With some 1.6 million twins born each year worldwide, the global twinning rate has risen by a third since the 1980s, to 12 per 1,000 deliveries from nine per 1,000 30 years ago, the study published in the journal Human Reproduction found.
Scientists behind the research say a “peak” in twin births may have been reached, particularly in high-income regions of Europe and North America where there is now an emphasis on refining fertility treatments to minimize multiple births.
The research team analyzed data on twinning rates for 165 countries between 2010 and 2015 and for 112 countries from 1980 to 1985.
They found a 71 percent rise in twinning rates in North America, as well as significant rises in many European countries and in Asia.