Premenopause

Premenopause is the stage of life before perimenopause, when cycles are regular and ovulation occurs in most months. It extends from the teen years to about the early or mid forties. Hormone levels remain fairly stable in these years. Estrogen (estradiol) and progesterone rise and fall in a consistent monthly pattern. FSH, the hormone that signals the ovaries to grow follicles, remains in the normal range. AMH, a marker of ovarian reserve, the remaining pool of eggs, peaks in the mid twenties. It then declines slowly, and the decline accelerates in the late thirties. For most women, premenopause is the period of highest natural fertility.

Charting the cycle during premenopause creates a baseline record. That record becomes useful later. Changes often appear on the chart years before they cause symptoms that lead to a clinic visit. These changes include mucus quality, cycle length, the length of the phase after ovulation, and spotting before a period. For RRM clinicians, years of charting form a long-term health record for the woman and the couple.¹

Premenopause ends when cycles begin to shift into the less regular, more variable pattern of Perimenopause. The body sets the timing, and age alone does not.