Early Onset of Menstrual Cycle

Early onset of the menstrual cycle occurs as part of a condition called precocious puberty. Precocious puberty causes sexual development to begin too early in young girls, resulting in early menstruation and other signs of sexual maturation. If the condition is diagnosed when the first signs of development occur, treatment can be started to delay early menstruation.

Identification

• Puberty usually begins in girls between the ages of 8 and 12, with the average onset of menstruation at age 12. Girls who experience precocious puberty experience the signs of sexual maturation, including menstruation, before the age of 8, according to Cincinnati's Children's Hospital Medical Center.

Symptoms

• The appearance of breast buds is usually the first sign of precocious puberty, followed by a growth spurt and development of pubic and underarm hair. Once breast development begins, the first menstrual period usually occurs within 24 to 30 months, according to the American Academy of Pediatrics.

Types

• Early menstruation can be caused by one of two types of precocious puberty. Central precocious puberty, also called gonadotropin-dependent precocious puberty, occurs when the brain releases hormones that start puberty too soon. Gonadotropin-independent precocious puberty is a less common form of the condition that causes the ovaries to begin releasing hormones too early.

Risk Factors

• Girls may be at risk for developing early menstruation and precocious puberty if they have an inherited disorder affecting the adrenal glands, are obese or have an underactive thyroid gland. Damage or defects in the brain and spinal cord can trigger the early release of hormones. Common problems affecting the brain and spinal cord include tumors; injuries; build up of fluid in the brain; blood flow obstructions; radiation treatment; or diseases that cause inflammation of the brain's membranes. Precocious puberty can also occur if a girl is exposed to creams containing the hormones estrogen or testosterone or if she has an ovarian tumor or cyst. In some cases, the condition occurs despite no known risk factors.

Effects

• Early menstruation and precocious puberty can have profound effects on a girl, both physically and emotionally. Few young girls are prepared to be physically mature at such a young age and may be embarrassed that they are having menstrual periods and are taller than their peers. Precocious puberty causes an initial growth spurt, but because puberty occurs well before it should, future growth may be limited and affected girls may be shorter than average. Early puberty is a risk factor for developing breast cancer later in life. Increased exposure to estrogen is associated with this risk, according to the Breast Cancer Fund.

Prevention/Solution

• Early onset of the menstrual cycle can be prevented if girls are diagnosed in the early stages of precocious puberty. Once menstruation begins, nothing can be done to reverse precocious puberty. Medication is available to block the release of hormones triggering puberty. If your doctor recommends this treatment, your daughter will receive injections every month until she reaches the normal age of puberty. At this point, the injections will be stopped and puberty will resume. If there is an underlying problem causing precocious puberty, such as a brain tumor or underactive thyroid gland, treating the problem will often stop early puberty.