#56: Late Bloomers: Catching Up on Puberty Knowledge

July 20, 2022 | By Sam Masur

Summary

There comes a time when we all grow up, and puberty is where all the hormonal magic happens. Puberty can be at different times for everyone, but when should pediatricians get concerned that it is too late, or too early? Join us with our guest Dr. Juanita Hodax, Pediatric Endocrinologist, to discuss hormone pathways, Tanner stages, and approaching puberty in a gender inclusive way.

Credits

• Producer: Jelina Castillo MD, MPH
• Executive Producer: Nick Lee MD
• Showrunner: Sam Masur MD
• Writer: Jelina Castillo MD, MPH
• Infographic: Jelina Castillo MD, MPH
• Cover Art: Chris Chiu MD
• Hosts: Chris Chiu MD, Justin Berk MD
• Editor:Justin Berk MD; Clair Morgan of nodderly.com
• Guest(s): Juanita Hodax MD

Puberty Pearls

1. Know typical timing of puberty
2. Know exam and do exam
3. Check hormone levels to start can help with next step, then refer

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Puberty Notes

Overview of Puberty

Puberty is the transition from a childhood body to adult body.  Pediatricians should start assessing for puberty with Tanner stage exams at all well child exams starting at 7 years old. 

• For children with testes, testicular volume increase is the first sign of puberty and usually occurs at 9-14 years old. 
• For children with ovaries, breast bud formation is the first sign of puberty and usually occurs from 8-12 years old. 
• Andrenarche refers to the increase of facial, axillary, and pubic hair growth and maturing of apocrine glands, which often goes with puberty but is not part of the definition of true puberty.  
• Height and growth spurt is also associated with puberty, with height velocity reaching 8-10cm/year increased from 5-6cm/year growth prior to puberty initiation. In assessing growth, bone age, which is an X-ray of the left hand to assess growth plates. Growth plate maturity is driven by estrogen and testosterone. 

Physiologically, true puberty is determined by the Hypothalamus-Pituitary-Gonadal (HPG) Axis. Some unknown gene activates the hypothalamus to release GnRH in a pulsatile manner to start puberty. This causes the pituitary to release FSH and LH, which the stimulates gonads to release estrogen and testosterone.

In determining puberty history, it is important to assess the start and tempo of puberty. It is important to also to get a history of parent’s puberty, such as mother’s menarche and father’s growth spurt timing. Finally, when discussing puberty, it is important to use inclusive language that allow children to explore their gender identity in puberty, such as people with ovaries or people with testes. 

Delayed Puberty

Delayed puberty is defined as lack of pubertal signs or Tanner Stage 1 at 14 years old for children with testes and 12-13 years old (depending on source) for children with ovaries. This can be independent of signs of adrenarche.

First, get a good history, family history of puberty, and assess the growth curve. Pertinent history includes signs of anosmia, history of chemotherapy, history of traumatic brain injury or trauma, and concerning neurological symptoms like headaches or visual changes. Next step is to evaluate with morning hormone lab levels of LH, FSH, testosterone, and estrogen. A bone age may be considered in the work-up as well. 

Expert Opinion: Dr. Hodax would send the lab work in children with testes ≥ 14 years old if they lack pubertal signs.

Delayed puberty can be considered in different categories:

• Constitutional delay – the most common, also known as “late bloomer”, but is a diagnosis of exclusion. Treatment may involve follow-up or may consider 3-6months of low dose testosterone to help trigger puberty.
• Hypogonadotropic hypogonadism – Seen with low LH/FSH and low Testosterone/Estrogen. Differential includes assessment of other pathologies for central dysfunction such as brain imaging
• Hypergonadotropic hypogonadism – Seen with elevated LH/FSH and low Testosterone/Estrogen. Consider gonadal dysfunction, tumor, or genetic syndromes such as Kleinfelter’s Syndrome or Turner’s Syndrome

Referral to a pediatric endocrinologist after these initial assessments is preferred for further evaluation and treatment. They can determine if treatment with growth hormone may benefit.

Precocious Puberty

Precocious puberty can be more variable in age based on observational studies, but typically should be concerning if there are signs of puberty at 6-8 years old in children with ovaries or <9 years old in children with testes. Precocious puberty is more likely to be pathological in children with testes. It is important when getting a history and physical to determine if the concern is for isolated premature adrenarche, concerning signs of progression in Tanner stages, or concern for early menarche. Isolated premature adrenarche is generally less concerning. Risk factors for precocious puberty include obesity, environmental stress, exposure to environmental endocrine disruptors, infant born SGA, and prematurity. 

Similarly, initial work-up for precocious puberty includes initial morning hormone levels of LH, FSH, testosterone, and estrogen. Bone age can also determine if height and growth may be affected if bone age is older than chronological age. 

Precocious puberty can be considered in different categories:

• Idiopathic – the most common, though a diagnosis of exclusion
• Hypergonadotropic hypergonadism – Seen with elevated LH/FSH and elevated Testosterone/Estrogen. More concerning for brain or pituitary pathologies
• Hypogonadotropic hypergonadism – Seen with low LH/FSH and elevated Testosterone/Estrogen. Consider gonadal tumor, exogenous hormones.

Referral to a pediatric endocrinologist after these initial assessments is preferred for further evaluation and treatment. They can determine if treatment with growth hormone may benefit, as early puberty may indicate premature growth plate closure and limit height potential. Treatment usually involves GnRH agonist to disrupt the pulsatile GnRH that initiates puberty, and can at times may help with height preservation.

Goal

Listeners will understand the normal progression of puberty and how to identify delayed or precocious puberty and initial work-up.

Learning objectives

After listening to this episode listeners will…  

1. Recall the basic HPG axis and what can occur when there are problems with each part of the axis
2. Be familiar with Tanner Staging and important physical exam findings in assessing puberty
3. Recognize the important ages of when to be concerned for abnormal puberty
4. Understand initial work-up for abnormal puberty
5. Understand how to obtain a good pubertal history and determine what key history can help rule out certain disorders

Disclosures

Dr Hodax reports no relevant financial disclosures. The Cribsiders report no relevant financial disclosures. 

Citation

Castillo J, Hodax J, Lee N, Masur S, Chiu C, Berk J. “#56: Late Bloomers: Catching Up on Puberty Knowledge”. The Cribsiders Pediatric Podcast. https:/www.thecribsiders.com/ July 20, 2022.