Twins are more common than ever—the rate of twin births has roughly doubled in the last 40 years in the world’s wealthiest countries. The reasons for the boom in twinning are the increase in medically assisted reproduction and hormonal treatments that stimulate ovulation. Another factor contributing to the boom is the rising age of first-time mothers: older mothers tend to produce two eggs per cycle because of natural hormonal changes. Along with the boom, researchers are studying anew the many challenges and benefits of twin births.

Key Takeaways:

• Over the last 40 years, the twinning rate has roughly doubled in the world’s wealthiest countries.
• Medically assisted reproduction and advancing age of mothers both increase the chances of a multiple births.
• The global twinning rate has slowed since its peak in the early 2000s. It has leveled off in many developed countries, and in some, such as Sweden and the Netherlands, it has gone into decline.

“Over the last 40 years, the twinning rate has roughly doubled in the world’s wealthiest countries, leading to a veritable twin boom.”

https://www.telegraph.co.uk/women/family/the-tantilising-truth-about-twins—and-why-theyre-more-common-t/