Patients with karyotypically normal spontaneous premature ovarian failure (as defined by screening protocol 91-CH-0127, i.e. women who have at least 4 months of amenorrhea, two FSH levels above 40 mIU/ml, at least one month apart, and a normal 46, XX karotype, diagnosed with premature ovarian failure prior to the age of 40) who are between the age of 18 and 42 years will be candidates.