Why did early puberty spike during the pandemic?

ITALY NOTICED FIRST. IT WAS THE FIRST COUNTRY TO lock down during the COVID-19 pandemic, and later in 2020, researchers at Florence's Anna Meyer Children's University Hospital were the first to point out a puzzling trend: more young girls than ever before had been showing up at the hospital with clear signs of early-onset puberty.

- HALEY WEISS

The cases weren't unique, but their frequency was. Since early-onset-or "precocious"-puberty first gained widespread clinical attention in the 1990s, it's become steadily more common worldwide. Defined as the appearance of secondary sex characteristics such as breasts, pubic hair, and vocal changes in girls 8 or younger and boys 9 or younger, precocious puberty has been difficult for researchers to attribute to a single cause. But a mysterious, pandemic-generated spike in cases has provided experts with a new opportunity to revisit their dominant theories in hopes of an answer. Case studies have now rolled in from clinics around the world, many of which saw at least a two-or threefold increase in precocious-puberty diagnoses after March 2020. In China's Henan province, for example, doctors at 22 facilities saw five times as many cases in 2020 as they did in 2018.