As women start to reach their late forties their bodies start to undergo a hormonal change once again. Females in general have a maximum number of oocytes (eggs) established at 20 weeks of gestation (fetus). As the finite number of oocytes decrease through life until about age 52, the ovaries start to atrophy. As the ovaries start to atrophy, the hormones, specifically estrogen, are no longer produced. This results in menstrual cycles become relatively shorter and more irregular, leading to accelerated follicular loss in the 10 years prior to menopause.
Eventually this leads to anovulatory cycles with only occasional ovulation. Periods start to become irregular and have inconsistent patterns usually longer (ex. >35 days between cycles). This transition phase from menstrual irregularity to final menstrual period is referred to as the Menopausal Transition. Menopause is defined as the point in time one year after the cessation of menstruation. Below shows a table hormone levels in relation to the two main common concerns of menopausal symptoms: hot flashes (vasomotor symptoms) and vaginal dryness.
|Early Menopausal Transition
||Variable length (>7 days from normal)
|Late Menopausal Transition
||>2 skipped cycles + intervals of amenorrhea of >60 days
|Final Menstrual Period
||12 mo without period or none
||Vasomotor sx decline (30%)
As the body undergoes these changes, women can have an increased risk for certain conditions. These include cardiovascular disease, vaginal atrophy, incontinence, breast changes, osteoporosis, thinning of the skin, and emotional distress.