Women of reproductive age who will receive treatment for cancer that includes chemotherapy may participate in a study measuring ovarian function over time. Eligible women are asked to complete a questionnaire, a menstrual diary, a brief physical examination, an ultrasound, and a blood test before, during and after cancer treatment.

A total of 7 study visits will be completed at 3 month intervals including 1 visit prior to treatment, and at least 2 visits after completion of treatment. Duration of study participation is 18-30 months, depending on length of treatment.

Review and Documentation of Cancer Therapy will be abstracted from the clinical oncology chart by the oncology offices caring for the patient. Treatment will be summarized in terms of chemotherapeutic type, duration and cumulative dose; total radiation dose and location; history and type of bone marrow transplantation; and any surgery. Any attempts at fertility preservation or use of gonadotropin releasing hormone agonist treatment during cancer therapy will be captured as well.

Inclusion Criteria for exposed population:

• Postmenarchal females to be treated with chemotherapy
• between the ages of 11-35 years,
• with a uterus and at least one ovary

Inclusion Criteria for unexposed population:

• healthy postmenarchal females
• no prior or planned exposure to chemotherapy
• between the ages of 11-35,
• with a uterus and at least one ovary
• regular menstrual cycles (21-35 days)

Exclusion criteria for all subjects:

• positive pregnancy test at enrollment
• lactation within the previous 1 month,
• previous treatment with chemotherapy or radiation therapy with the exception of radioactive iodine for thyroid cancer.
• previous diagnosis of an illness associated with premature ovarian failure (Turner's syndrome, Fragile X permutation carrier)
• endocrine disorder associated with irregular menstrual cycles (Cushing's disease, Thyroid disease, hyper-prolactinemia, congenital adrenal hyperplasia).

Additional exclusions for the unexposed population:

• a history of infertility, defined as at least 12 months of unprotected intercourse without conception
• polycystic ovary syndrome (PCOS)

Postmenarchal females, ages 11-35, who will require chemotherapy; An unexposed cohort balanced to the exposed cohort with respect to age and oral contraceptive use.