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Zaria was just 9 years old when a nurse practitioner delivered news that rocked her world: The young girl was already showing signs of puberty development, and she was on track to get her period within the next year.

Surprised by this timeline, Zaria’s mother, Chanell, worked with a pediatrician to plan healthier meals, hoping that managing her daughter’s weight gain could give her a couple more precious years with her childhood unchanged.


Puberty came for Zaria anyway. She developed breasts in the fourth grade, and her weight began to fluctuate in new, unexpected ways. She balked at the idea of needing to carry around pads at school, worried that classmates would judge her.

“I didn’t get to explain the educational part of puberty to her before it took place. We were stuck dealing with the changes and learning all at the same time,” said Chanell, who lives with her three daughters in the Boston area.

Dealing with the emotional changes was the hardest part. The oldest child, Zaria had always been clear and communicative about her feelings. But she now developed a rebellious streak, stomping through the house slamming doors. Sometimes she’d stop to go up to Chanell, distraught, and say, “Mom, I don’t even know why I’m crying or why I’m upset.”


Her story is part of a growing worldwide trend, one that has parents and physicians concerned. Girls across the globe are hitting puberty earlier than ever before. A 2020 study of 20 countries across six continents found that the median age when girls first experience breast development has dropped by about three months every decade since 1977, shifting from about 10.5 to 9.5 years old. Some research suggests this rate may be accelerating since the Covid-19 pandemic began in 2020. In fact, today’s medical definition of precocious puberty — breast budding at the age of 8 or younger — does not even apply to Zaria, though she hit puberty years before the average girl growing up in the 1980s and ’90s and ahead of nearly all her classmates.

To understand the impact of this trend, STAT spoke with parents, researchers, and women who went through precocious puberty, many of whom requested that only their first names be used because of how painful and personal the experience had been. Their stories made clear that young girls going through early puberty face unique mental health challenges, from hormonal fluctuations to bullying, unwanted sexual attention, and intense feelings of isolation. Friends, parents, and strangers are looking at their evolving appearance with brand-new eyes and may treat them differently than before — for better or worse.

And when an adolescent girl doesn’t receive sex education and support from her school, health care providers, or family, she’s often left feeling alone and trapped in a body she hardly recognizes.

A clear trend with no clear explanation

For now, less than 1% of the U.S. population is impacted by precocious puberty, according to statistics cited by the National Institute of Child Health and Human Development, with similar rates reported in South Korea and Denmark.

But the average age of puberty onset keeps dropping, and researchers aren’t sure why, though there are plenty of possible reasons. Previous studies have shown that improved hygiene and nutrition access correlate with better child health and thus earlier maturation. But there are more troubling potential explanations, too. Childhood obesity rates in the U.S. have risen from 5% in the 1970s to 20% by 2018, and some studies link obesity to earlier pubertal development in girls and delayed puberty in boys.

Higher stress levels during early childhood have also been associated with precocious puberty. And there’s a growing number of early-stage studies examining the relationship between rising early puberty rates and endocrine-disrupting chemicals found in everyday items such as plastic packaging, beauty products, pesticides, furniture, and electronics.

“We already know that many of the things we’re consuming are increasing our risk for health complications and changes. And puberty falls in line with that,” said Adeiyewunmi (Ade) Osinubi, an emergency resident physician at Penn Medicine in Philadelphia.

Women who experience precocious puberty also face an increased risk of breast cancer as adults, as well as coronary heart disease and stroke. And there is some evidence that precocious puberty correlates with higher rates of polycystic ovary syndrome, a hormonal condition that can cause period irregularity and cysts to grow outside one’s ovaries.

Girls who undergo precocious puberty are also more likely to be victims of bullying during childhood, and they have a higher risk of depression, social anxiety, eating disorders, and substance misuse. Recent research has also demonstrated that precocious puberty has mental health effects that persist into adulthood, with young adults who went through early puberty more likely to experience depressive symptoms than those who matured at an average age.

Precocious puberty is associated with similar poor mental health outcomes in boys — despite the long-held belief that early maturation is universally advantageous for boys. But there’s less research available overall, in part because precocious puberty occurs about 10 times more frequently in girls than in boys.

Some scientists hypothesize that feeling out of sync with peers during adolescence can contribute to feelings of loneliness and depression. Others point out that looking older than your age can provoke unusual treatment from teachers, parents, and friends, which can be a source of lasting trauma on its own.

“Puberty is a biopsychosocial experience,” said Natasha Chaku, an assistant professor at Indiana University Bloomington who specializes in adolescence and cognitive development. “There are internal biological changes happening in your body, but they are accompanied by a host of psychological and social changes.”

Dana knows this firsthand. The 24-year-old, who lives in Boston, started puberty when she was in fourth grade. It was an intensely lonely experience. Her mom had gone through puberty at an older age and was “very empathetic, but couldn’t relate” to her daughter’s experience. And her fluctuating body only exacerbated her discomfort around peers, she said, many of whom bullied her throughout elementary and middle school.

“Traumatic sounds like the wrong word, but it kind of was,” she told STAT. “I hated it. I felt uncomfortable with how quickly these changes had come on.”

Dana elected to get breast reductions later in life, citing a lifelong discomfort with her chest. So did Jacque, a 37-year-old journalist who started puberty at 8. As a child growing up in Miami Beach, Fla., Jacque noticed that she was growing breasts and hips much faster than the other girls in her ballet and tap classes. Though her mom assured her that her changing body was normal, Jacque hated how girls in her dance program commented that her curvy body was less “ballerina-like.” The social and emotional impact of those experiences, she said, lasted well into her late 20s.

“I would lock myself in the bathroom with tubs of coconut butter and just be rubbing it on my chest trying to get rid of stretch marks,” Jacque said. “And with my period, I remember I would hide in the bathroom and strip the pad really quietly and hope no one would know what I was doing. I felt like I was growing uncontrollably and nothing I did would stop it.”

Experts note that while adolescent girls work to relate to their changing, unfamiliar bodies, the rest of the world often sees physical maturation as a green light to treat a child like an adult woman.

“Let’s say you have an 8-year-old girl who looks like she’s 12. Most people are going to relate to her like a 12- year-old,” said Aviva Sopher, a pediatric endocrinologist and assistant professor at Columbia University Irving Medical Center. “That can have repercussions on the child because they’re given different standards than other kids their age, and they may be unrealistic.”

Jacque put it more bluntly: “It’s not just children who are making fun of you, but adult men are now looking at you because they perceive that you’re of age or whatever is happening in their sick mind.”

Decades later, she still remembers how a grown man once made a pass at her while she was out with her mom; Jacque was 12.

“My mom started yelling at him that I was a little girl,” she said. “I remember just cowering there and trying to make myself small.”

For Jacque, who is Latina, and for other Black and brown girls, the challenges of early puberty are compounded by racial stereotypes from both peers and their own doctors.

“When I was in medical school, we learned that Black girls achieved puberty earlier than white girls,” Osinubi said. “There are implications of having this statement out there if it doesn’t pay attention to the sociopolitical factors that contribute to these disparities.”

Research does suggest that, on average, Black girls tend to begin breast and pubic hair development earlier than their white counterparts. However, in recent years, scientists have pushed back on the idea that earlier puberty is the result of biological differences between races. They’ve instead urged medical professionals to consider early puberty as yet another health disparity affected by structural racism, pointing out that Black girls have higher rates of poverty, obesity, exposure to environmental pollutants, and stress.

Another complication is that Black children are already frequently perceived as older than they are, a phenomenon known as adultification bias. Osinubi argues that because the vast majority of precocious puberty research focuses on white adolescents, the limited understanding of Black and brown children’s experiences reinforces the idea that Black girls’ precocious puberty is natural, while white girls who develop young are robbed of their childhood.

There’s a similar glaring absence of research on precocious puberty in transgender children. Such gaps are especially worrisome because the limited research that’s out there shows that, among transgender children, the onset of puberty without access to puberty blockers is associated with greater gender dysphoria, anxiety, and suicidal ideation.

“Before puberty, if you feel like you’re not in the right body, your body at least isn’t providing you evidence of that. You have a fairly flat and agendered body in some ways,” said Chaku of Indiana University Bloomington. “But part of physical maturation makes you look more like a man or more like a woman. And if your identity isn’t aligned with that, it can produce a lot of mental stress.”

Scarce resources for children in need

It’s not a guarantee that every primary care doctor will understand how precocious puberty impacts their patients, especially since it has only become a more common phenomenon in the last couple decades. Parents who want guidance on how to navigate early puberty with their child often seek out a pediatric endocrinologist, who can help them track bone development, pituitary hormone levels, and other changes that unfold during puberty.

But there are only 639 practicing pediatric endocrinologists listed in the Pediatric Endocrine Society’s directory of the U.S., and Americans living in medical deserts may have to travel long distances to connect with one. Sex education, typically a child’s first opportunity to learn about puberty in a classroom setting, is not a requirement for 21 states in the U.S. Only California, Oregon, and Washington require comprehensive sex ed, a form of sex ed that the Guttmacher Institute, a research and policy organization, characterizes as “medically accurate, LGBTQ inclusive, and culturally and age appropriate.”

Moreover, sex education is normally introduced into school curriculum around fourth or fifth grade, and, by that point, children with precocious puberty may have already begun to menstruate or grow breasts.

There are sometimes preventative measures for undergoing puberty early. When Columbia University’s Sopher has patients below the age of 8 who she and their parents feel “cannot handle going through puberty,” or may face health complications like bone maturation and height issues, she sometimes prescribes puberty blockers to slow down their development. The most common puberty blockers, gonadotropin-releasing hormone analogs, inhibit the hormone that kick-starts puberty in both sexes. The treatment has been FDA-approved since 1993, and there have not been any long-term health risks associated with using puberty blockers.

In spite of these facts, puberty blockers are not a viable option for most children undergoing precocious puberty. The rise in state laws banning gender-affirming care, which also uses puberty blockers, has had a chilling effect on the use of these drugs. And many parents aren’t aware that puberty blockers are an option for their children until precocious puberty is well underway, even in states with access to the treatment.

For children who aren’t at risk of health complications but are worried about developing before their peers, Sopher said, “it’s really important for parents to help their kids understand the process, explain that it’s a normal thing, and make them feel good about themselves.”

It was an uphill battle for Chanell and Zaria to come to terms with Zaria’s early puberty. But Chanell reassured Zaria that even though her body was changing in ways she didn’t understand, she wasn’t going through it alone. She explained that sometimes Zaria might feel moody or sad before or during her period, and that it’s OK to take time away from her siblings and parents if she wasn’t feeling good.

Chanell got Zaria, who she describes as a “really girly girl,” a cute bag to hold her pads for school, and “it made it easier for her to go to the bathroom being prepared in that way.” Now, at 11 years old, Zaria is much more well-adjusted to the challenges of adolescence, Chanell said, even if she got there sooner than anticipated.

These are exactly the kind of frank, encouraging conversations Chaku stressed families and schools need to have with children.

“I don’t want to pathologize puberty because it is normal and healthy. It’s essential for our bodies to become stronger and mature and employ important cognitive changes,” she said. “It’s going to happen. We should do a good job of preparing kids for it so they don’t wake up and say, ‘Who’s the stranger in the mirror?’”

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