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Recent news reports in Europe and elsewhere have mentioned a possible link between the
use of oral contraceptives (OCs) containing the newest formulations of progestins and the
development of blood clots. Family Health International recently provided background
materials to scientists and health providers worldwide to help clarify this relationship.
The following is from a "Question and Answer" sheet circulated by FHI.
Question: Oral contraceptives (OCs) have been studied for
years. Why have concerns about cardiovascular risks been raised now?
Answer: A large epidemiological study, designed to gain more information on
contraceptive use and cardiovascular disease, has been conducted by the World Health
Organization (WHO). While study results are preliminary, some results were published in
British newspapers.
According to a news release from WHO, these preliminary study results suggest that users
of combined oral contraceptives containing estrogen and the newest synthetic progestins,
desogestrel and gestodene, appeared to have twice the risk of venous thromboembolism
(blood clots) than users of pills containing the older progestins, levonorgestrel and
norethindrone.
This information prompted the British Committee on the Safety of Medicines, the country's
regulatory agency, to issue a warning about contraceptives containing the newest
progestins. The government has said women may continue using the new progestin pills if
they accept the higher risk.
Question: Which brands of pills contain desogestrel and
gestodene?
Answer: The pills are marketed under the following brand names: Desolett,
Femodeen, Femoden, Femodene, Femodene ED, Femovan, Frilavon, Ginoden, Gynera, Gynovin,
Marvelon, Marviol, Mercilon, Microdosis, Microdiol, Minulet, Minulette, Moneva, Myvlar,
Planum, Practil, Prevenon, Securgin, Segurin, Tri-Minulet, Triadene, and Varnoline. The
names of contraceptives vary from country to country.
Question: Does the U.S. Agency for International
Development (USAID) supply these brands?
Answer: No. None of these brands are distributed by USAID.
Question: Should women who are using pills containing the
newest progestins, desogestrel and gestodene, stop taking these pills? Should they switch
to another brand of pills?
Answer: It is important to remember that the new study results concern only the
newest synthetic progestins, desogestrel and gestodene. The results do not apply to the
older progestins, levonorgestrel and norethindrone.
Healthy women who use pills containing the newest progestins desogestrel and gestodene
have a very, very low risk of developing blood clots. However, women who have questions or
who may be interested in switching to a different brand of oral contraceptives should be
advised to see their family planning provider.
To help put risks in perspective, both the World Health Organization and the International
Planned Parenthood Federation (IPPF) have issued statements regarding the recent reports.
The organizations agree that because the incidence of venous thromboembolism in women of
reproductive age throughout the world is very low, an excess risk from using combined oral
contraceptives would affect a relatively small number of women.
WHO states that "current users of oral contraceptives containing desogestrel or
gestodene appear to be at higher risk of venous thromboembolism compared to users of pills
containing levonorgestrel or norethindrone." WHO, however, has noted that "the
possibility that these results are due to chance or bias cannot be excluded entirely and
the results should be confirmed by further studies."
WHO advises "that until further information becomes available, low estrogen dose oral
contraceptives containing progestins other than desogestrel and gestodene may be
preferred."
The IPPF statement says that women wishing to use pills containing desogestrel or
gestodene should be counseled about the possibility of increased risks for thromboembolic
disease. If women already using these pills wish to switch to a brand without desogestrel
or gestodene, they should complete their present cycle of pills before beginning a new
brand.
Dr. Olav Meirik, chief of WHO's Task Force for Epidemiological Research in Reproductive
Health, said in a WHO written statement that "it should be understood that health
risks from pills containing the progestogens desogestrel or gestodene are very low. The
risks from an unplanned pregnancy or unwanted pregnancy are far greater in
comparison."
Question: What do we know today about contraceptive use and
cardiovascular disease?
Answer: When oral contraceptives were first introduced more than three decades
ago, they contained high doses of the hormones estrogen and progestin. Since then, the
amount of these hormones has been significantly reduced in combined oral contraceptives.
Older oral contraceptives contained 75 to 100 µg of estrogen. Newer formulations of oral
contraceptives contain 20 to 50 µg of estrogen. Also, researchers have developed an oral
contraceptive that contains no estrogen, only progestin (the mini-pill, progestin-only
pill or POP).
Early scientific research on the relationship between cardiovascular disease and oral
contraceptive risks studied women using high-dose pills. Scientists found that estrogen
promoted blood coagulation; consequently, blood clots were more likely to develop in oral
contraceptive users than in nonusers.
Because newer combined pills contain smaller amounts of estrogen, they have less effect on
blood coagulation, so the risks of heart disease are very rare with these pills. However,
because estrogen can still affect blood coagulation as well as blood pressure and lipids,
these methods are not generally recommended for women who have a history of heart disease
or blood clots or women who are at risk for heart disease. (These studies did not include
pills containing desogestrel and gestodene.)
Modeling studies at Family Health International have examined the risks of death for women
who use low-dose oral contraceptives. These studies have found that among users of
lose-dose OCs, the risk of cardiovascular death exceeds the risk of death due to pregnancy
only among women who smoke 25 or more cigarettes a day and who are over 30 years of age.
Question: Are there guidelines or recommendations that
healthcare providers can follow when counseling women about oral contraceptives and
cardiovascular disease?
Answer: The World Health Organization has prepared a document entitled Improving
Access to Quality Care in Family Planning: Medical Eligibility Criteria for Initiating and
Continuing Use of Contraceptive Methods. The criteria were prepared after discussions
among international health experts, including physicians from Family Health International.
According to these recommendations, use of low-dose oral contraceptives presents an
unacceptable health risk in:
- women with high blood pressure (a systolic level greater than 180 and a diastolic level
greater than 110)1
- women with blood vessel disease (vascular disease)
- women with a history of deep venous thrombosis (blood clot) or pulmonary embolism (blood
clot in the lung), or women who presently have these conditions2
- women with current ischemic heart disease, or a history of ischemic heart disease
- women with a history of stroke
- women with complicated heart valve disease
- women who are planning to undergo major surgery and will be immobile for a long period
of time
- women who have severe headaches accompanied by disturbances in vision
- women who are both over age 35 and are heavy smokers (more than 20 cigarettes per day).
In addition to these women who should not use OCs, the WHO guidelines say the use of
combined oral contraceptives is generally not recommended for women who have certain
conditions that might increase their risks of heart disease, since the risks of using the
method usually outweigh the benefits of pregnancy protection. Unless more appropriate
methods are not available or acceptable, OCs are generally not recommended for the
following women:
- women who are over age 35 and are light smokers (20 or fewer cigarettes per day)
- women who have a history of high blood pressure with a systolic pressure of 159 to 179
and diastolic pressure of 99 to 109
- women who have had vascular disease or diabetes for more than 20 years.
Footnotes
- High blood pressure or hypertension is a risk factor for
heart disease. Women who are using combined OCs and develop a blood pressure level of
160-179 (systolic) over 100-109 (diastolic) should discontinue using combined oral
contraceptives. Women with mildly elevated blood pressure can use combined oral
contraceptives.
- Healthy women face little risk of developing deep venous
thrombosis or pulmonary embolism; however, women who already have these conditions should
consider another family planning method.
For more information, visit Family Health International's Website at www.fhi.org
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