9 and 16 years, the body starts making the hormone testosterone. Testosterone is responsible for many of the changes that happen during puberty, such as deepening of the voice, facial hair growth, enlargement of the penis and scrotum, and sperm production. Men make testosterone throughout their lives, but as they age the body may produce smaller amounts. After puberty, men have the potential to make sperm their entire life. However, if the body is not able to make testosterone, men are not able to make sperm. FEMALES The ovaries are the primary reproductive organs in females. Immature eggs are pres- ent in the ovaries before birth. Females are born with all the eggs they will ever have, as the body is not capable of making more eggs. During puberty, hormones from the brain send signals telling the ovaries to begin maturing a small number of eggs. In most cycles, one of these eggs will be released each month. If no pregnancy occurs, a woman will have her period. Estrogen and progesterone are hormones made by the ovaries once a young woman starts puberty. They are also necessary for breast growth and other changes that happen during puberty, such as widening of the hips and pubic and underarm hair growth. Menopause takes place when the ovaries stop re- leasing eggs, which typically occurs when a woman is in her 50s. During menopause, estrogen production dramatically decreases and menstruation stops. PREGNANCY Pregnancy occurs when an egg is fertilized by sperm. This typically occurs during sexual intercourse, but some women may require medical treatment (such as in-vitro fertilization) to have children. Pregnancy cannot occur if a male or female has not yet reached puberty or if the body is not able to make the hormones needed for reproduction. n EFFECTS OF CANCER TREATMENT ON FEMALE REPRODUCTION AND PUBERTY Children diagnosed with cancer may have problems with fertility later in life. This is a potential long term side-effect of cancer treatment. The reproductive health of children treated for cancer will depend on many factors, including the age at the time of diagnosis, total dose and types of chemotherapies, and the combination of chemotherapy and radiation. Sometimes radiation and chemotherapy given together may increase a child’s risk for fertility problems. Other problems children may develop after cancer treatment include: • precocious puberty: puberty that begins before age 8 years in girls • delayed puberty: puberty that begins after age 14 years in girls • arrested puberty: puberty that has started but then stops before completion
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