PERIMENOPAUSE

Thomas Higgins, MD
6/25/2000

Menopause is defined as a lack of menses for 1 year and has an average age of onset in the United States of 51 years of age. Less than 1% of women develop menopause at age 40 or less and less than 5% develop it after 55 years of age. Smoking & stress are 2 factors which seem to lower the age of menopause. The perimenopause precedes actual menopause by anywhere from 2 to 10 years and lasts 4 years on the average. It generally begins in the late 30’s or early 40’s and is heralded by a change in the menstrual cycle. The usual change is a shortening of the cycle length. The average menstrual cycle length at 15 years of age is 29 days and decreases to 26 days by 40 years old. The first hormonal change is a drop in inhibin production by the ovary followed closely by an increase in FSH production by the pituitary. The high FSH levels actually cause an overall increase in the estrogen levels early on but the estrogen levels tend to vary widely leading to a "roller coaster" effect. Progesterone levels fall and menstrual bleeding becomes progressively irregular. In the United States, 500,000 to 600,000 hysterectomies are performed each year with 55% in the 35 to 49 year old age group. Many of these hysterectomies are related to the irregular bleeding due to the perimenopause. Other sign & symptoms including headaches, hot flashes, sleep disturbance, change in sex drive, irritability, memory problems, acne, unwanted hair growth, abnormal vaginal bleeding, urinary urgency, stress urinary incontinence, bone loss, acceleration of atherosclerosis, rheumatoid arthritis make their appearance in many women. Unfortunately, this is also a peak time for unplanned pregnancies, second only to the teenage years. Pregnancies in this age group are not only unplanned but half are terminated by elective abortion. Pregnancy in this age group is also associated with increased maternal mortality, an increased risk of fetal chromosomal anomalies and a higher incidence of spontaneous abortion.

On occasion depression & hypothyroidism can be mistaken for perimenopausal symptoms and should be screened for.

In 1990, the FDA approved the use of oral contraceptives in healthy, nonsmoking women over the age of 40. The benefit of low dose oral contraceptives (20 micrograms of ethinyl estradiol) in the perimenopause

include:

• Regulation of menstrual bleeding with an associated reduction in hysterectomies.
• Prevention of unplanned pregnancies.
• Relief of many symptoms related to the perimenopause.
• Reduction of bone loss.
• Reduction of atherosclerosis.
• A reduction of ovarian cancer & rheumatoid arthritis risk.

The only cloud on the horizon appears to be the association of estrogen use and breast cancer risk. Most experts acknowledge that there is a slight increase in breast cancer risk with long term estrogen use but the absolute numbers appear to be small. In addition, there is some indication that the risk of dying from breast cancer is actually less in women who use estrogen. The decreased risk of dying may be related to better surveillance in this group of people.

Finally, women should not be kept on birth control indefinitely. Even low dose oral contraceptives represent approximately 4 times the estrogen dose recommended for postmenopausal women. Since 99% of all pregnancies have occurred by age 50 & pregnancy is very rare after age 53, I would recommend changing to standard postmenopausal estrogen & progesterone doses after age 53.

The reader is referred to the companion article on estrogen replacement therapy for a discussion of the pros & cons of ERT after menopause.