Spina Bifida Family Support

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Precocious Puberty in Children Who Have Spina Bifida with Hydrocephalus


Gregory S. Liptak, MD, MPH; University of Rochester Medical Center; SBAA Professional Advisory Council

Puberty describes the normal biological changes in the body that lead to sexual maturity, the ability to produce children. Precocious puberty means that the biological changes begin much earlier than expected. The timing and sequence of puberty are controlled by hormones. Children who have spina bifida with hydrocephalus-especially girls-are more likely to have precocious puberty than other children.

Humans have a biological clock in the brain that triggers the production of hormones in the brain at the appropriate age. One of these is called luteinizing hormone-releasing hormone (LHRH). LHRH causes the pituitary gland to release hormones called gonadotropins. These hormones, in turn, flow through the blood stream and stimulate the ovaries in girls and testes in boys to make sex hormones. The sex hormones, especially estrogen in girls and testosterone in boys, cause sexual maturation.

The physical changes seen in puberty have been classified using a system called Tanner staging, where stage 1 is child-like (before puberty) and stage 5 is full maturity. In girls the usual sequence includes (1) start of breast development, (2) rapid increase in height and widening of the hips, (3) pubic hair, which appears six to 12 months after breast development, (4) axillary hair (hair under the arms), and (5) menstruation, which starts two to two-and-one-half years after breast development is noticed. A change in body odor may also appear early in this sequence.

The average age for the start of breast development in girls is nine to ten years. African-American girls have earlier onset of puberty than do white girls. In one study, for example, black girls started breast development 12 months before white girls did. Breasts typically take three or more years to go from Tanner 2 to Tanner 5. As with all biologic events, a range of normal occurs. However, if significant breast development begins before age seven years, it is considered precocious. (Occasionally girls will have some development of the breast, called thelarche, with no other signs of puberty. This isolated change is usually considered normal).

In males, the usual sequence includes (1) increase in the size of the testicles, (2) growth spurt, (3) increase in size of the penis, (4) pubic hair, and (5) axillary hair. If boys show significant development before age nine, it is considered precocious. Precocious puberty can cause several problems with growth and development. First, once the rapid growth spurt of puberty starts, the bones change and become more adult-like. For example, in girls, the growth spurt typically lasts for four years. After that time, the bones stop growing and become incapable of growing any more. Therefore, most children who start puberty too early will be shorter than they otherwise would have been (because the bones stop growing earlier than they would have).

The second major problem with precocious puberty is that bodily changes happen much earlier than in other children of the same age, which makes them different. As a result, children with precocious puberty may be teased about their sexual development; such teasing is especially common with girls who develop breasts. Or girls may be subject to sexual advances for which they are not psychologically ready. Boys may become more aggressive and hyperactive than their peers. In general, children with precocious puberty may feel isolated and rejected socially. Teachers and other adults may expect these children to act older than their ages. This, in turn, may frustrate the children because they cannot live up to expectations. The isolation and unrealistic expectations, which are common in children with spina bifida without precocious puberty, make functioning even more difficult.

Although it is not certain why children with spina bifida and hydrocephalus are more likely to have precocious puberty, most people believe that the hydrocephalus interferes with the biological clock. If your child has precocious puberty (before age seven in girls and before age nine in boys), or has an unusual sequence or too rapid sexual development, he or she should be evaluated by a physician or nurse clinician who is knowledgeable about these issues. Usually, a referral to an endocrinologist (a person who specializes in hormones) is made. If no other problems are found, the most commonly used treatment to delay the onset of puberty is to begin injections of a medicine that interferes with the hormonal system.

The most commonly used medicine is called leuprolide (Lupron). This medication, which is injected into muscles once a month, has a chemical structure similar to LHRH and fools the body (probably by making the pituitary glad less sensitive to the real hormone). It usually stops the progress of puberty after three to six months, and may reverse some of the changes that had already occurred. It usually is given for several years. Most people believe that treatment also allows individuals to be taller than they would have been without using the medication. Most importantly, the delay caused by the treatment should allow the children/teens (and parents) to adjust to their sexually maturing bodies and feelings, and help them develop a healthy sexual identity.

This information does not constitute medical advice for any individual.  As specific cases may vary from the general information presented here, Spina Bifida Family Support advises readers to consult a qualified medical or other professional on an individual basis.

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