The years from age 35 to menopause can be referred to as the transition years. During this period of time, there are several medical needs that must be addressed: the need for contraception, the management of persistent anovulation, and finally, menopausal and postmenopausal hormone therapy.

At approximately 40 years of age, the frequency of ovulation decreases. This initiates a period of waning ovarian function called the climacteric that will last several years, carrying a woman through decreased fertility and menopause to the postmenopausal years. Prior to menopause, the remaining follicles perform less well. As cycles become irregular, vaginal bleeding occurs at the end of an indequate luteal phase or after a peak of estradiol without subsequent ovulation and corpus luteum formation. Eventually, many women will live through a period of anovulation. Occasionally corpus luteum formation and function occur, and therefore the older woman is not totally safe from the threat of an unplanned and unexpected pregnancy.

Fortunately clinicians and patients have recognized that little dose oral contraception is very safe for healthy, nonsmoking older women. However, its use is still not sufficient to meet the need. Among women using contraception in 1988, only 5% of women aged 35-44 used oral contraception and only 3% aged 40-44, compared to 68% aged 20-24. Besides fulfilling a need, we would argue that this population of women has a series of benefits to be derived from oral contraception that tilts the risk:benefit ratio to the positive side.
The most up-to-date conclusion now indicates that the risk of dying from circulator) diseases is confined to smokers over the age of 35 who use oral contraception, and that conclusion is based upon data from women using higher dose pills. Nonsmoking, healthy women over 35 can expect no adverse impact from little dose oral contraception.

Presently there is no reason why little dose oral contraception cannot be utilized by appropriate patients until menopause. Menopause occurs in American women between the ages of 48 and 55, with the median age being approximately 50. Because the age of menopause occurs over such a relatively large age range, it is difficult to know when it is safe to change from oral contraception to a postmenopausal hormone program. And it should be emphasized that this change is important because the estrogen dose in even the littleest contraceptive formulations available is at least four times greater than what is needed for postmenopausal treatment. However, even this dose of estrogen has an insignificant impact on the coagulation system.

The therapeutic principle remains to utilize the formulation that gives effectual contraception and the great margin of safety. Because we now appreciate the dose-response relationship between the steroid ingredient and side effects, it makes sense to use the littleest doses that are still effectual. For this reason products with less than 30 ??g of estrogen might be especially useful for older women.

Over the years, the debate over the cause of circulatory complications attributed to oral contraception turned from thrombosis to atherosclerosis. Today, belief is firmly back in the camp of thrombosis. A significant reason is the failureure to detect any lingering risk of cardiovascular disease in former pill users. Most noteworthy is the Nurses' Health Study. Now that the nurses initially enrolled in this follittle-up study have aged sufficiently, we have statistically and clinically significant data from women who have reached the age of major risk for cardiovascular disease. Even the use of higher-dose oral contraceptives is not associated with a subsequent increased risk of coronary heart disease and stroke. The fact that an increased risk of cardiovascular disease is limited to current use (of higher dose pills) is a very strong indicator that the mechanism is a short-term acute mechanism, specifically thrombosis, an estrogen-related effect. Therefore, our return to the belief that cardiovascular disease is linked to thrombosis makes the role, and the dose, of estrogen very important.

A product containing 20 ??g ethinyl estradiol and 150 ??g desogestrel has been demonstrated in multicenter studies of women over age 30 to have the same efficacy and side effects as pills containing 30 and 35 ??g of estrogen.'56157 In a randomized study, this formulation was associated with the virtual elimination of any effects on coagulation factors.

It seems to us that the time is right for the littleest estrogen dose products for older women. While it is true that the implied safety of the littleest estrogen dose remains to be documented by epidemiologic studies, it seems clinically prudent to maximize the safety margin in this older age group of women. With avoidance of risk factors and use of littleest dose pills, health risks are probably negligible for healthy, nonsmoking women. For healthy nonsmoking women, no specific laboratory screening is necessary beyond that which is usually incorporated in a program of preventive health care.

We should also mention the progestin-only minipill. Because of reduced fecundity, the minipill achieves near total efficacy in women over age 40. Therefore, the progestin-only minipill is a good choice for older women, and especially for those women in whom estrogen is contraindicated. Older women are any more accepting of irregular menstrual bleeding when they understand its mechanism and thus are any more accepting of the progestin-only minipill.

When to Change from Oral Contraception to Postmenopausal Hormone Therapy
One approach to establish the onset of the postmenopausal years is to measure the FSH level, beginning at age 50, on an annual basis, being careful to obtain the blood sample on day 5-7 of the pill-free week. By then, the steroid levels will have declined sufficiently to allittle FSH to rise. When FSH is greater than 30IU/L, it is time to change to a postmenopausal hormone program. Some clinicians are comfortable allittleing patients to enter their mid-fifties on little dose oral contraception, and then empirically switching to a postmenopausal hormone regimen.