Testing for LH and Puberty in Children

The article was written by MSc Tran Quynh Trang - Doctor of Biochemistry, Laboratory Department - Vinmec Times City International General Hospital

The average age of puberty for girls is 8-13 years old and boys are 9-14 years old. Testing the LH response to gonadotropin-releasing hormone, along with other tests, can help diagnose the reason for delayed puberty.

Precocious puberty is the development of pubertal changes before the age of 8 in girls and 9 years of age in boys with an increase in gonadotropins and/or sex steroids, accelerating body growth and bone age.
Precocious puberty is classified: gonadotropin-dependent and gonadotropin-independent. Gonadotropin-dependent growth is almost always mediated by the pituitary gland and is therefore referred to as central precocious puberty.
Growth is not dependent on gonadotropins, often the result of a disorder of the gonads or adrenal glands, also known as peripheral precocious puberty. Precocious puberty is 3-5 times more common in girls than in boys.
Luteinizing hormone (LH) is a glycoprotein hormone consisting of 2 non-covalently bound subunits (alpha and beta). LH is produced by the anterior pituitary under the regulation of hypothalamic gonadotropin-releasing hormone (GnRH) and feedback from gonadal steroid hormones. In children, LH together with follicle-stimulating hormone (FSH) is used to diagnose early and late puberty.
Evaluation of precocious puberty includes measurement of LH and FSH to help determine whether there is an age-related increase in gonadotropin (gonadotropin-dependent) or sex steroid secretion that is independent of FSH and LH (non-gonadotropin-dependent).
In gonadotropin-dependent precocious puberty, basal LH levels are often elevated in the pubertal range and show a pubertal (increased height) response to GnRH stimulation. In gonadotropin-independent precocious puberty, LH levels are initially low and unresponsive to GnRH stimulation.

Delayed puberty is clinically defined as the absence or incomplete development of secondary sex characteristics at 14 years of age in boys and 12 years of age in girls. Delayed puberty is usually due to inadequate gonadal steroid secretion.
Therefore, measuring LH, FSH, Estradiol or testosterone levels is useful to distinguish primary and secondary causes of delayed puberty.
Reference values ​​
Female:
< 1 year old: < 0.02 – 18.3 IU/L 1 – 8 years old: < 0.02 – 0.3 IU/L 9 – 10 years old: < 0.02 – 4.8 IU/L 11 – 13 years old: <0.02 – 11.7 IU/L 14 – 17 years old: < 0.02 – 16.7 IU/L Men:
< 1 year old: < 0, 02 – 5.0 IU/L 1-8 years old: < 0.02 – 0.5 IU/L 9-10 years old: < 0.02 – 3.6 IU/L 11-13 years old: 0.1 – 5 ,7 IU/L 14-17 years old: 0.8- - 8.7 IU/L In young children, high levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) are associated with growth. development of secondary sex characteristics at an abnormally young age, which is a hallmark of gonadotropin-dependent precocious puberty (also called central precocious puberty).
In pseudoprecocious puberty, signs and symptoms are the result of increased levels of estrogen in girls or testosterone in boys. During late puberty, LH and FSH levels may be normal or lower than expected for young adults in this age group.
Children with precocious puberty are at risk of psychological consequences: shyness, lack of confidence due to early sexual development and reduced adult stature due to rapid bone maturation. Affect the quality of children's learning. In girls, due to early endocrine disruption, polycystic ovary syndrome affects fertility. Therefore, early detection, finding out the causes and timely treatment will partly prevent the consequences of early puberty.

Baby will be examined with a leading expert in Pediatric Endocrinology with high expertise and experience. Having sex hormone blood tests, bone age assessment tests, brain MRI scans Or some other tests. More in-depth testing, in order to determine the right cause of precocious puberty and timely treatment. When registering for the Early Puberty Screening Package, customers will receive: The package includes 1 in-depth examination with a pediatric endocrinologist and appropriate tests and diagnostic imaging depending on the child's gender:
X-ray -Fine, lateral or oblique (hand) metaphyseal (hand) General abdominal ultrasound (for girls) Determination of FSH (Follicular Stimulating Hormone) Determination of LH (Luteinizing Hormone) Estradiol determination (for girls) ) Testosterone determination (for boys).