The purpose of this study is to have a better understanding of the normal blood levels of AMH in females from 0-18 years of age and how the blood AMH levels correspond to a female's reproductive development.

Anti-mullerian hormone (AMH) is a chemical in the body that is found in the blood that can estimate the ability of a female to have her own children. It is widely used in adult female cancer patients to predict the onset of menopause and/or the inability to have children that can be associated with chemotherapy and/or radiation treatment. Normal blood levels of AMH are better understood in adults than in children and adolescents. The purpose of this study is to have a better understanding of the normal blood levels of AMH in females from 0-18 years of age and how the blood AMH levels correspond to a female's reproductive development. With a better understanding of normal AMH levels in children, we may be able to better assess a girl's risk of not being able to have children if she is a cancer patient, and may be able to offer her and her family options to increase the chances of having her own children.

Inclusion Criteria:

1. Pre- and post-pubertal females

2. Ages 0-18 years old

3. Tanner Stage I- V

4. Undergoing routine outpatient surgical procedure

   1. Hernia repair (inguinal, umbilical, epigastric)
   2. Excision of benign mass
   3. laparoscopic cholecystectomy

Exclusion Criteria:

1. Previous diagnosis of an illness associated with premature ovarian failure (Turner's syndrome, Fragile X permutation carrier) or endocrine disorder associated with irregular menstrual cycles (Cushing's disease, poorly-controlled Thyroid disease, hyperprolactinemia, polycystic ovary syndrome, and congenital adrenal hyperplasia) or insulin-dependent diabetes mellitus or autoimmune disorders

2. Previous diagnosis of any malignancy or any history of systemic/local chemotherapy, radiation therapy, or stem-cell transplant.

3. Previous surgical excision of one ovary or both ovaries

4. Pregnant females

5. All inpatient surgical patients

6. Undergoing non-routine outpatient surgical procedures

   1. Central venous catheter placement
   2. Supprelin insertion/removal
   3. Breast mass excision
   4. Gastrostomy tube insertion