What is Precocious Puberty?

Nurturing Young Girls Photo credit: Irina Murza on Unsplash

Precocious puberty (also called early puberty) the clinical term for a medical condition characterized when a child’s body begins changing into that of an adult (puberty) too soon. When puberty begins before age 8 in girls and before age 9 in boys, it is diagnosed as precocious puberty. Physiological and anatomical changes during puberty include rapid growth of bones and muscles, changes in body shape and size, and development of the body’s ability to reproduce.

About 1 out of 5,000 children are affected by precocious puberty. Many experts say that, on average, puberty onset is starting earlier in the U.S. than it did in the past. The average age of menstruation has stayed roughly the same. Yet studies suggest that early signs–like breast development–are happening a year earlier than they did decades ago.

Certain conditions, such as infections, hormonal disorders, tumors, brain abnormalities or injuries, and even exposure to chemical compounds may bring about precocious puberty, though the exact cause is often difficult to pin point. Possible other causes of early puberty that are currently being studied include environmental chemicals and obesity. Treatment for precocious puberty typically includes medication (hormone blockers) to pause the process and temporarily delay any further development.

Symptoms of Precocious Puberty

Signs and symptoms of precocious puberty include any or all of the following before age 8 in girls (age 9 in boys):

  • Breast growth and first period (girls).
  • Enlarged testicles and penis, facial hair and deepening voice (boys).
  • Growth of pubic or underarm hair.
  • Rapid overall growth.
  • Emergence of acne.
  • Advancement of adult body odor.

Causes of Precocious Puberty

To understand what causes precocious puberty in some children, it’s helpful to know what causes normal puberty. The onset of puberty is normally triggered by the hypothalamus in the brain producing a hormone called gonadotropin–releasing hormone (GnRH).

When this hormone reaches the pituitary gland—a small bean–shaped gland at the base of the brain—it leads to the production of more hormones estrogen in the ovaries (for girls) and testosterone in the testicles (for boys). Estrogen is involved in the growth and development of female sexual characteristics. Testosterone is responsible for the growth and development of male sexual characteristics.

The onset of precocious puberty in some children will manifest itself in one of two ways:

  1. Central Precocious Puberty (or CPP).
  2. Peripheral Precocious Puberty (or PPP).

Central Precocious Puberty

In central precocious puberty (also known as gonadotropin–dependent precocious puberty), the pattern and timing of the steps in the process are normal, but the onset of symptoms begins at too young an age. For the majority of children with this condition, there’s no underlying medical problem and seemingly unclear identifiable reasons for the early onset.

Precocious puberty has a genetic component and is less common in boys. The puberty process is started by early secretion of hormones called gonadotropins. Gonadotropins include luteinizing hormone (LH) and follicle stimulation hormone (FSH). In girls, precocious puberty may be caused by the early maturity of the hypothalamus, pituitary glands and ovaries. This is the most common type of precocious puberty. The causes for this type are difficult to identify, although, in rare cases it may be brought on by:

  • A tumor in the brain or spinal cord (Central Nervous System).
  • A defect in the brain present at birth, such as excess fluid buildup (Hydrocephalus) or a noncancerous tumor (Hamartoma).
  • Radiation to the brain or spinal cord.
  • Injury to the brain or spinal cord.
  • McCune–Albright Syndrome—a rare genetic disease that affects bones and skin color, and causes hormonal imbalances.
  • Congenital Adrenal Hyperplasia—a group of genetic disorders involving abnormal hormone production by the adrenal glands.
  • Hypothyroidism—a condition in which the thyroid gland does not produce enough hormones.

Peripheral Precocious Puberty

The less common peripheral precocious puberty (also known as gonadotropin–independent precocious puberty) occurs without the involvement of the hormone (GnRH) in your brain that normally triggers the start of puberty. Instead, the cause is the release of estrogen or testosterone into the body because of problems with the ovaries, testicles, adrenal or pituitary glands. It is this presence of estrogen or testosterone in your child’s body that is the impetus for this type of precocious puberty.

The following may lead to PPP in both girls and boys:

  • A tumor in the adrenal or pituitary glands that stimulates the release of estrogen or testosterone.
  • McCune–Albright Syndrome.
  • Exposure to external sources of estrogen or testosterone, such as creams, ointments or medications.
  • Ovarian cysts and/or tumors.
  • A tumor in germ cells (cells that produce sperm) or in Leydig cells (cells that produce testosterone).
  • A rare genetic disorder called Gonadotropin–Independent Familial Sexual Precocity, which is caused by a defect in a particular gene that can result in the early production of testosterone, usually between ages 1 and 4.

Diagnosing Precocious Puberty

To diagnose precocious puberty, the child would need to see a Pediatric Endocrinologist. This specialty doctor will:

  • Review your child’s and family’s medical history
  • Do a physical exam
  • Run blood tests to measure hormone levels
  • X–ray your child’s hand and wrist (to determine your child’s “bone age”)

Determining The Type Of Precocious Puberty

To do so, the Pediatric Endocrinologist will perform a test called a gonadotropin–releasing hormone (GnRH) stimulation test, which involves blood work and injection of hormones. In children with CPP, the GnRH hormone will cause other hormone levels to rise. In children with PPP, other hormone levels stay the same.

Additional Testing For Central Precocious Puberty
  • Magnetic resonance imaging (MRI). A brain MRI will show if any brain abnormalities are causing the early onset of puberty.
  • Thyroid testing. Testing the child’s thyroid functions to check for any signs of slow thyroid function (hypothyroidism), such as fatigue, sluggishness, increased sensitivity to cold, constipation, a drop in school performance, or pale dry skin.
Additional Testing For Peripheral Precocious Puberty

Other tests are also necessary for children with PPP to find the cause of their condition. For example, additional blood tests to check other hormone levels, or (in girls) perform an ultrasound to check for ovarian cysts or tumors.

Treatments For Precocious Puberty

Treatments for precocious puberty depend on its root cause. If there is no clear identifiable cause, the child may not need treatment depending on age and condition’s rapid progression.

Treating Central Precocious Puberty

Most children with CPP for which there is no underlying medical condition can be treated with medication. The currently approved treatment is with drugs called LHRH analogs. These synthetic (man–made) hormones block the body’s production of the sex hormones that induce puberty. Positive results can usually be seen within a year of starting treatment. LHRH analogs are generally safe and generally have no side effects in children.

This treatment is called GnRH analogue therapy and includes either a monthly (or quarterly, or biannual) injection of a hormone blocker, such as leuprolide acetate (Lupron Depot) or triptorelin (Trelstar, Triptodur Kit), to delay further progression of this condition. These injections continue until the child reaches a more typical age for puberty. After the child stops receiving the medication, the process of puberty resumes as expected.

Another treatment option for CPP is a histrelin implant (Vantas) which lasts for up to a year. This treatment is effective but it requires a surgical procedure. The implant is placed under your child’s skin through an incision in the inner area of the upper arm. After a year, the implant is removed or if necessary, replaced with a new one.

Treating Peripheral Precocious Puberty

If the cause of your child’s precocious puberty is an underlying medical condition, treatment of that condition first is necessary to stop the progression of PPP. Usually, the process of puberty will stop once the condition is treated.

Risks for Precocious Puberty Photo credit: Eye For Ebony on Unsplash

Risk Factors for Developing Precocious Puberty

Factors that increase a child’s risk of a precocious puberty outcome include:

  • Gender: Girls are much more likely to develop precocious puberty. Continue reading below for a more in–depth look at the phenomenon of early puberty in American girls and the new standard for what is “normal.”
  • Race: Precocious puberty appears to affect African–Americans more often than children of other races.
  • Weight: Children who are significantly overweight have a higher risk.
  • Exposure to hormones: Coming in contact with an estrogen or testosterone cream, ointment, or any substance that contains these hormones (adult medication or dietary supplements) can increase the risk.
  • Medical conditions: Precocious puberty may be a complication of McCune–Albright Syndrome or Congenital Adrenal Hyperplasia—conditions that involve abnormal production of male hormones (androgens). Or it may also be associated with hypothyroidism (Hashimoto’s).
  • Exposure to radiation therapy: Radiation treatment for tumors, leukemia or other conditions can increase the risk.

Complications of Precocious Puberty

The possible consequences of precocious puberty include:

  • Short height: Children with precocious puberty may grow quickly and be tall at first. But, because their bones mature more quickly than is normal, they also stop growing earlier than normal. As a result, their adult height ends up shorter than average.
  • Social and emotional problems: Girls and boys who begin puberty long before their peers may be more self–conscious about their body changes, contributing to loss of self–esteem and experiencing depression or substance abuse. Boys can become more aggressive and also develop a sex drive inappropriate for their age.

Coping and Support

Children who begin puberty early may feel different from their peers. It’s often the case that feeling different can cause social and emotional problems, including early sexual experimentation. If your child is having difficulty coping, seek counseling. You can download the full (PDF) report from Nationwide Children’s Hospital here.

Prevention of Precocious Puberty

Some of the risk factors for precocious puberty, such as petrochemicals, microfibers, added excess sugars, all types of plastics, etc. are insidious and ubiquitous, and can hardly be avoided. But, there are things you can do to reduce your child’s risk:

  • Keeping your child away from external sources of estrogen and testosterone—such as adult prescription medications, or dietary supplements containing these hormones.
  • Encouraging your child to maintain a healthy weight by providing them with a healthy diet full of fresh fruits, veggies, whole grains, healthy fats, and few animal products. It’s also a good idea to avoid junk food, fast food and any processed foods.
  • Avoiding plastic packaging whenever possible. Other options for storage and packaging materials are: glass, metal, wood, ceramic, paper, wax and fabric. See my other posts on proper food storage practices, alternatives to cling wrap, homemade linen bread bags, sandwich & snack bags, and fabric bowl covers.
  • Avoiding health, beauty, household and cleaning products that contain: BPAs, BPBs, boric acid and sodium borate, butylated hydroxyanisole (BHA), coal tar ingredients (including aminophenol, diaminobenzene and phenylenediamine), formaldehyde and formaldehyde releasers (Bronopol, DMDM hydantoin, diazolidinyl urea, imidazolidinyl urea and quaternium–15), hydroquinone, lead and lead acetate, methylisothiazolinone (MI/MIT), methylchloroisothiazolinone (MCI) and benzisothiazolinone (BIT), zinc oxide and titanium dioxide nanoparticles, oxybenzone, bleach (check out my post for brightening whites with bluing instead of toxic chemicals), ammonia, parabens (specifically propyl–, butyl–, isopropyl–, and isobutyl– parabens), PEGs and ceteareth (check out my post for making your own laundry detergent), petroleum distillates, phthalates (check out my post for making your own deodorant), resorcinol, toluene, triclosan and triclocarban, Vitamin A compounds (retinyl palmitate, retinyl acetate, retinol) and sulfates (check out my posts on DIY your own health and beauty care products). For a more thorough list visit the Environmental Working Group (EWG’s) website.
  • Avoiding health, beauty, household and cleaning products that contain fragrances: Federal law doesn’t require companies to list the chemicals in their fragrances on product labels. Fragrances can contain hormone disruptors and are among the top five allergens in the world.

Atypical Precocious Puberty

Some very young girls (usually from 6 months to 3 years old) may show breast development that later disappears or may last but without any of the other physiological changes related to puberty. This is called premature thelarche and usually doesn’t have long lasting effects.

Similarly, some girls and boys may have early growth of pubic and underarm hair, or body odor that isn’t related to other changes in sexual development. This is called premature adrenarche. These children may need to see their pediatrician to rule out “true” precocious puberty. But most need no treatment and will display the other expected signs of puberty much later, at the usual age.

Precocious Puberty in American Girls

The Breast Cancer Fund conducted an analysis of existing data on the subject of precocious puberty for research indicating that early menarche is a risk factor for later outcomes of breast cancer. The analysis integrated biomedical knowledge with environmental and chemical research, social and cultural determinants and their consequences. The resulting publication published in August 2007, The Falling Age of Puberty in U.S. Girls, by Sandra Steingraber—traces the complex and intertwined relationships between puberty, physiological, psychological and environmental conditions; and the instigator of the involuntary maturing of our nation’s girls.

Based on the data in Steingraber’s publication, one can conclude that the trigger for girls’ early puberty onset is a combination of factors that launch physiological changes that set the stage for other developmental responses. To truly ameliorate this trend, we need to recognize and appreciate the interaction between our environment’s chemical overload and our bodies’ physical and social development.

Early Puberty: The New Normal and Why We Should Be Concerned

Despite the fact that precocious (early) puberty is becoming the norm and not the exception, it is remarkable how little is known about puberty in general. While we understand the basic neural and hormonal routes that combine to launch the process of puberty–including growth of breasts (thelarche) and pubic hair (pubarche), and introduce first menstruation (menarche)–this process has no predetermined onset or length. Timing varies widely and can be influenced by a wide range of environmental factors and cues that are not entirely known. “Normal” puberty onset can range from ages 8–13 and takes, on average, 1.5–6 years to complete.

The Past

Credible and reliable documentation exists from the past century to establish that the average age of first menstruation in American girls has declined by several years, from an average of 17 to 13. And during the last 50 years the age of first menstruation continued to decline, but at a much slower rate and with wide ethnic disparity. Caucasian girls in the U.S. now menstruate at an average age of 12.6 years; African American girls at 12.1 years; and Hispanic girls at 12.2 years. However, it’s unclear how far back these differences can be traced, since most historical documentation focuses on Caucasian American and immigrant European girls.

There is also plenty of documentation concerning changes in the early signs of puberty development, such as the onset of breast budding, and growth of pubic and underarm hair. Data from the last few decades show a continuing decline in the onset age for both. In short, girls get their first periods a few months earlier than girls 40 years ago, but they get their breasts 1–2 years earlier than 40 years ago.

About 30 years ago, new pediatric guidelines advised that girls who developed breasts and pubic hair beginning at age six or seven were not necessarily “abnormal.” These guidelines were published in Pediatrics, the journal of the American Academy of Pediatrics, and were based on several studies. The most important was Marcia Herman–Giddens’ study of 17,000 girls ages 3–12, patients of over 200 pediatricians across the country. The study was based on girls evaluated throughout 1992–93, but was not published until 1999.

Previous standards of “normal puberty” had been set more than 30 years before, based on a study of fewer than 200 girls in a single British orphanage in the 1960s.

The Present

When pediatricians revised their guidelines on puberty in 1999, the emphasis on the likely cause of greater numbers of girls affected by this early onset of puberty was the obesity epidemic, since it is scientific fact that obesity affects hormones, and vice versa.

In May 2009, a Danish study was published in the same journal, which reported that Danish girls were developing breasts at an earlier age than they had been 15 years before, which was the time of the earlier U.S. study. The Danish study found that the onset of puberty (measured by breast development) dropped from a mean age of 10.9 in 1991 to 9.9 in 2006 and the average age for beginning menarche dropped 3.5 months. This change could not be attributed to obesity, because the girl subjects’ Body Mass Index (BMI) remained constant.

In the U.S., 50% of Caucasian girls now show signs of breast budding before age 10, with as many as 14% showing breast development by age 8. The average age of breast budding for African American girls is just under 9 years, with a significant percentage of breast development before age 8. It is now the opinion of most endocrinologists that the falling age of puberty among U.S. girls is real and ongoing. It’s less clear why it’s happening and what should be done about it.

Exposure To Chemical Cocktails

Most experts agree that the decline in the age of puberty onset is attributable to decreased rates of disease, increased nutrition, and the female of the species’ ability to adapt sexual maturation to environmental cues (e.g., health, food, shelter). This is why it is difficult to speak of a “normal” age and time for its onset. Humans are adaptive creatures and normal depends upon our personal and communal conditions. This also means that normal puberty development is not necessarily “good” or “healthy;” it’s simply a marker response to external conditions impacting internal functions.

In the last several decades, especially, this trend appears to be responding to stimuli that is beyond nutrition and health. Numerous studies have linked exposure to environmental chemicals, particularly endocrine–disrupting chemicals, which can mimic hormones in the body (see my previous post on glyphosate in weed killers) to health concerns like shortened gestational periods in fetal development, low birth–weight babies, incidence of Autism, chronic metabolic disorders, increased obesity, and poor insulin regulation.

The Scientific Evidence

Children are continuously exposed to low–level endocrine disruptors in their diets, drinking water and air supply. Chemical flame retardants, e.g., polybrominated biphenyls (PBBs), have been linked to earlier menstruation and pubarche. Similarly, high levels of dioxin exposure have been associated with elevated risks for breast cancer and early menarche. Other chemical compounds that have been linked to early puberty onset are found in many commonly used products like hair tonics, pesticides, and building materials.

Animal studies indicate that prenatal and post–natal exposure to bisphenol A (BPA, a synthetic hormone used in all polycarbonate plastics, and the lining of food and beverage cans) can induce CPP. A urine analysis from a sample of American girls indicates the presence of endocrine disruptors and traces of known human contaminants such as phthalates and BPA.

This chemical cocktail may be a significant factor in this new normal rate of early puberty onset in American girls. There isn’t enough research to say for sure—only enough to raise red flags. What we do need to know is how these chemical contaminants combine with other known risk factors for early puberty—smoking, obesity, physical inactivity, and psychosocial stressors—to contribute to early puberty onset, and what other ramifications could this have on human development.

Girls Or Women

In addition to the increased health risks, there are also social reasons to be concerned about the declining age of puberty. As the onset age of puberty declines, we are put upon to separate the notion of childhood from physiological development. There are few well–designed studies of the psychological and social impact of early puberty. But these studies focus on evaluating the experiences of girls who menstruate at an early age, rather than the larger number of girls who develop breasts and pubic hair at an early age.

After all, an 8–year–old girl with breasts is no less a child than one without breasts. However, common sense would tell us that an 8–year–old girl who looks like a teenager would feel self–conscious and have trouble making friends with peers. Yet researchers are only just beginning to study these girls.

Girls who enter puberty early are more likely to experience more psychological stress, anxiety, negative self–image, suicidal ideation, substance abuse and tobacco use. Girls with early puberty are also more likely than their counterparts to become victims of physical and sexual violence, and are more vulnerable to deviant peer pressures and fathers’ hostile feelings. Maturing “too” young girls are not equipped to cope with their own confusing sexual feelings, the impact that their appearance has on boys and men, and the risks of “consensual” sexual activity. They cannot prevent themselves from being sexually abused or exploited.

Photo credit: Andriyko Podilnyk on Unsplash
Photo credit: Andriyko Podilnyk on Unsplash

In a study of 1,700 high school students from Oregon, girls who matured earlier than their peers were more likely to drink and use tobacco, and were twice as likely to have substance abuse and disruptive behavioral disorders. They also tend to have low self–esteem, poor coping skills, miss more days of school, and were more likely to attempt suicide.

A study of 33 girls ages 6–11 diagnosed with precocious puberty found that the subjects exhibited more behavioral problems than their peers. They were more likely to feel depressed, aggressive, socially withdrawn, have sleeping problems, and report obsessive behaviors.

They have lower levels of academic achievement. According to a national study of 1,800 girls between the ages of 15 and 19, they become sexually active at a younger age, and are more likely to experience an unwanted teenage pregnancy. Among Caucasian and Hispanic girls (but not African American girls), early menarche was associated with earlier marriage. Teenage pregnancy, sexually transmitted diseases, and the emotional trauma of sexual abuse are all of serious concern.

In American society, early puberty boys do not experience these behavioral patterns or outcomes. In our society, early puberty alters a girl’s social interactions in ways that lead to trauma and erode away at the possibilities for a healthy, stable and positive adulthood. As a nation, we must initiate strategies to prevent early puberty and help those who are already affected.

What Can Be Done About This Social Phenomenon

There is a woeful lack of information about the chemicals in our environment and their consequences for human health. Ideally, we should be able to rely on our elected officials and government agencies to ensure the routine screening for endocrine–disrupting chemicals and other agents in our air, water, and food, as well as monitoring the effects these chemicals have on human development.

We also need to study any damaging effects of chemicals on human and environmental health prior to their mass use in consumer products. Governments also need stricter regulations on the use and release of these chemicals into the environment.

Sources:
Mayo Foundation for Medical Education and Research (MFMER)
Precocious puberty – Symptoms and causes – Mayo Clinic
https://www.mayoclinic.org/diseases-conditions/precocious-puberty/doctors-departments/ddc-20351819
Precocious Puberty (for Parents) – Nemours Kids Health
https://kidshealth.org/en/parents/precocious.html
Reviewed by: Tal Grunwald, MD, Date reviewed: September 2019
Precocious Puberty – Stanford Children’s Health
https://www.stanfordchildrens.org/en/topic/default?id=precocious-puberty-early-puberty-90-P01973
WebMD Medical Reference
Causes and Consequences of Early Puberty – WebMD
https://www.webmd.com/children/causes-symptoms
Reviewed by Renee A. Alli, MD on June 25, 2019
Nationwide Children’s Hospital
Precocious (Early) Puberty in Girls: Symptoms and Diagnosis
https://www.nationwidechildrens.org/conditions/early-puberty-in-girls
Duke University Health System
When Is Puberty Too Early? | Duke Health
https://www.dukehealth.org/blog/when-puberty-too-early
Deanna Adkins, MD, Oct 1, 2013
National Institutes of Health, US National Library of Medicine
Precocious puberty in girls – NCBI
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3603023/
Indian Journal of Endocrinology and Metabolism
by S Chittwar – ‎2012
Early Puberty for Girls: The New “Normal” and Why We Need to Be Concerned
By Kathleen O’Grady, September/October Newsletter 2009
https://www.nwhn.org/early-puberty-for-girls-the-new-normal-and-why-we-need-to-be-concerned/
Early Puberty in Girls | National Center for Health Research
Diana Zuckerman, PhD, Winter 2001
http://www.center4research.org/early-puberty-girls/
Environmental Working Group
https://www.ewg.org/

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.