For most children, puberty begins between the ages of 7 and 14. However, that onset can shift drastically for children with central precocious puberty (CPP). While CPP in boys can usually be traced to a specific cause, for girls, the condition more often comes in the form of idiopathic central precocious puberty (ICPP).
According to the National Organization for Rare Disorders (NORD), puberty is considered precocious in girls who experience menarche before age 10 or breast tissue growth before a certain age — 6.8 years old for Hispanic patients, 6.6 years old for Black patients and 8 years old for white patients. Certain risk factors increase a child's risk of developing CPP, including obesity and early exposure to sex hormones. However, any girl can develop this condition.
While the gonadotropin-releasing hormone (GnRH) stimulation test is a current diagnostic standard, research now indicates that ultrasound may also provide valuable diagnostic information. Offering ultrasound in your practice as a testing alternative may encourage greater cooperation from both patients and their parents, making it easier for you to get the information you need to create a treatment plan.
Symptoms and Complications of ICPP
NORD reports that estimates of CPP's prevalence vary widely, from one in five to one in 10,000 children. Symptoms of idiopathic central precocious puberty are similar to those that occur at the normal onset of puberty. According to American Family Physician, typical symptoms of precocious puberty in girls include:
- Acne.
- Body odor.
- Early breast development.
- Early onset of menarche.
- Pubic or underarm hair.
- Rapid growth.
Other symptoms such as bone maturation beyond the child's age may be apparent upon X-ray examination.
The effects of early onset puberty can be distressing to both the patient and their family. In many cases, girls with ICPP stop growing earlier than usual, leading to diminished stature in adulthood. Early development of secondary sex characteristics such as breasts may make children self-conscious about their appearance. This, in turn, may lead to embarrassment, confusion and diminished self-esteem.
Current ICPP Diagnostic Guidelines and Their Limitations
The GnRH stimulation test has long been the diagnostic test of choice when evaluating for ICPP. However, this method does have limitations, including the need for multiple blood samples and relatively low sensitivity in spite of the test's high specificity. Additionally, the necessity of intravenous access may cause significant discomfort for patients and their parents.
Using Ultrasound to Diagnose ICPP
Ultrasound has emerged as an alternative diagnostic method for suspected idiopathic central precocious puberty. This minimally invasive exam is simple to complete and provides detailed information about the early maturation of internal reproductive organs.
Using a transabdominal approach, clinicians may evaluate patients using several parameters, including:
- Uterine volume, length and transverse diameter.
- Fundus and the fundus/cervix ratio.
- Ovarian volume and circumference.
A study published in the Korean Journal of Pediatrics cites significant differences in uterine length, transverse diameter, volume and fundus in children with central precocious puberty. Increased uterine volume was later confirmed as a major predictive finding in a study published in the Chonnam Medical Journal.
Following Up With ICPP Patients
Fortunately, ICPP can be successfully treated with GnRH analogue therapy. This treatment prevents further maturation of the female reproductive system, stopping further symptoms and, along with other medications, encouraging normal growth and development.
Ultrasound comes into play again for monitoring ICPP treatment. A study in Frontiers in Pharmacology shows that measurements of uterine length and volume, together with other variables like ovarian length, are significantly decreased after the onset of treatment.
Patients generally continue receiving GnRH analogue therapy until they reach the age of normal puberty. During this time, regular ultrasound examinations may be used to evaluate the continued effectiveness of treatment.
While idiopathic central precocious puberty is a relatively rare condition, its effects may cause significant distress for pediatric patients. Pubertal development often proceeds normally despite the early start, but prompt diagnosis is critical for avoiding potential complications such as impaired growth. Using ultrasound as a diagnostic tool provides valuable clinical information while minimizing discomfort to the patient and their family.
