Puberty Occurs Earlier In Girls Today Than In Their Mothers

Puberty occurs earlier in girls today than in their mothers

The new scientific work collects and analyzes for the first time all studies that focus on thelarche or breast enlargement. Scientists consider thelarche to be the best marker for studying puberty.

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Puberty in girls now begins almost a year earlier than 40 years ago, according to a new study published in JAMA Pediatrics.

The new scientific work collects and analyzes for the first time all studies that focus on thelarche or breast enlargement. Scientists consider thelarche to be the best marker for studying puberty.

The authors of the new study believe that the age of the first menstruation (menarche) is a less successful marker, since in its assessment scientists are often forced to focus on the memories of women and girls. In addition, menstruation may not start at the very onset of puberty.

Scientists analyzed 38 studies that were conducted up to 2019. All of them included expert assessment of the condition of the girls' mammary glands. They found that the age of onset of breast development ranged from 9.8-10.8 years in Europe to 10.1-13.2 in Africa.

Analysis of the data showed that in the period from 1977 to 2013, the Telarche was "younger" by 0.24 years every decade. The study does not explain why girls' puberty became earlier, but scientists have speculated.

“The current global obesity epidemic may partially explain the observed changes in the age of onset of puberty, which is determined by the onset of thelarche,” the authors write. Some studies, the researchers note, suggest that certain chemicals in the environment can affect hormones and also play a role.

Scientists believe their study matters because it indicates that experts need to re-evaluate criteria for early puberty. This will help avoid unnecessary referrals of children for medical examinations.

In a comment to the Guardian, Professor Peter Hindmarsh of University College London, who was not involved in the study, said it was not clear at this time if puberty was simply earlier or if it started earlier and became longer. He also noted that this study at this stage is unlikely to change the way doctors define early puberty.