Puberty starts when the pituitary gland begins to produce two hormones, luteinizing hormone (called LH) and follicle-stimulating hormone (called FSH), which causes the ovaries to enlarge and begin producing estrogens. Puberty changes occur when the body starts making sex hormones. These changes normally begin to appear in girls between ages 8 to 14 years old. The growth spurt starts shortly after breasts begin to develop, and the first menstrual cycle begins about 2-3 years later. A girl who has not started to have breast development by the age of 13 is considered to have a delayed development. With delayed puberty, these changes either don’t occur or if they do, they don’t progress normally. Delayed puberty is more common in boys than in girls.
Causes of Delayed Puberty:
Late Bloomers: Some teens are ‘late bloomers’ who just happen to start puberty later than most children their age. Being a late bloomer is the most common cause of delayed puberty. It’s not caused by a medical problem and usually doesn’t need treatment. Late bloomers will eventually start puberty on their own.
Constitutional Delayed Puberty: Also, some girls with delayed puberty are simply late maturers, but once they start, puberty will progress normally. This is called constitutional delayed puberty and is more common in boys than girls.
Delayed Puberty can be Hereditary: Delayed puberty is often inherited from parents. So it is more likely to occur if the mother started her periods after age 14 or if the father was a ‘late bloomer’.
Body fat can be a reason: Decreased body fat is the most common cause of delayed puberty in girls. It can be seen in girls who are athletic, particularly in gymnasts, ballet dancers or swimmers. It can also be seen in girls with anorexia nervosa, who are vigorously involved in dieting.
Any illness can be an issue: Lastly, it can be seen in a number of chronic illnesses in which body fat is often decreased. Some girls with delayed puberty may have problems with their ovaries. The ovaries are either not developing properly or are being damaged. This is referred to as primary ovarian insufficiency. Occasionally, girls may have their ovaries damaged by the body’s immune system.
Hormones: Finally, some girls fail to start puberty because of a lack of the pituitary hormones LH and FSH, also called gonadotropins. This can occur when there are other pituitary deficiencies as well, including growth hormone.
Delayed puberty can be easily diagnosed. The endocrinologist will order blood tests to measure levels of LH, FSH, and estradiol and, in some cases, other tests. After the diagnosis, appropriate treatment can be started.