Method of early detection of risk of infertility and ovarian aging in and treatment of a human female who has not experienced infertility and is not otherwise indicated to have premature ovarian aging. A number of CGG repeats on each allele of the isolated FMR1 gene is measured by using an assay, and a testing regimen is performed only when the determined number of CGG repeats on one of the FMR1 gene alleles is less than 26. The testing regimen includes periodically measuring serum level of a hormone related to fertility, such as Anti-Müllerian Hormone, Follicle Stimulating Hormone and/or estradiol over a period of about three to eight years and, after each measurement, determining if the measured serum level is less than a set confidence interval for a human female of the same age of the female. If so, the human female is treated for premature ovarian aging.