According to the first comprehensive survey of twin births around the world, published in the Human Reproduction journal, the world has reached a peak twin, as more twins are being born than ever before.
The study concludes that currently about 1.6 million twins are born each year worldwide, with one in every 42 children born a twin! This is a whopping three times more than the births of twins in the 1980s.
The researchers of the study collated information on twinning rates from 165 countries all across the world for the periods of 2010 to 2015, and compared the results with rates for 1980 to 1985.
“The trends are really quite striking,” said Prof Christiaan Monden, a professor of sociology and demography at Oxford University and the author of the study. “Over the past 40 to 50 years we’ve seen a strong increase in twinning rates in rich, developed countries, and that has led to more twins in both a relative and an absolute sense than we’ve seen ever before.”
It is widely believed that the increase use of medically assisted reproduction such as IVF, ICSI, artificial insemination and ovarian stimulation, and delayed childbearing have resulted in this phenomenon. Studies have proven that the likelihood of having natural, non-identical twins increases with age and peaks between 35 and 39 years old.
According to the report, there has been a 32 per cent rise in Asia and a 71 per cent rise in North America in the twin birthing rates in this period. However, the geographies of Africa and Asia contribute to about 80 per cent of all twin deliveries in the world at present.
Prof Monden explained the reason for this fact. “The twinning rate in Africa is so high because of the high number of dizygotic twins – twins born from two separate eggs – born there,” he said.
“This is most likely to be due to genetic differences between the African population and other populations.”
Isn’t this an interesting phenomenon? What do you think? Let us know what you think about this study in the comments section below.