Post

Twin births have risen dramatically since the 1980s. 🧵

10 Feb 2025

The share of births that are twins has risen over time. The chart shows data for France, Canada, the United States, and England & Wales in the Human Multiple Births Database.

Saloni

@scientificdiscovery.dev

10 Feb 2025

One reason is the use of reproductive technologies such as in vitro fertilization (IVF), which make it possible for many more couples to conceive. During procedures like IVF, multiple eggs can be used at the same time to maximize the chances of a successful pregnancy, which can lead to twin births.

Saloni

@scientificdiscovery.dev

Another reason for the rise in twin births is that the average age of women at childbirth has risen. Older women are more likely to have twin births, even without using reproductive technologies.

10/2/25, 12:36 pm0 reposts9 likes

Saloni

@scientificdiscovery.dev

10 Feb 2025

Twin births are a chance event, but data shows they can also be influenced by societal changes and reproductive technologies.

Saloni

@scientificdiscovery.dev

10 Feb 2025

You can explore the trends here, including for other countries:

ourworldindata.orgShare of births that are twinsThe share of deliveries that are twins, reported by each country.

Aveek Bhattacharya

@aveek18.bsky.social

11 Feb 2025

Is the apparent inflection (seems to have peaked and started to come down again) IVF related, too? Multiple birth rates with IVF appear to have fallen in the 21st Century

kellymb.bsky.social

@kellymb.bsky.social

15 Feb 2025

Yes, most IVF clinics will not do or strongly warn against the transfer of multiple embryos at a time. Research suggests it does not increase likelihood of pregnancy, only likelihood of multiples which brings additional risk in pregnancy.