Evidence Supports Safety of New Contraceptive Pills

Posted on Fri, June 22, 2007

By Dr. Judy Bliss

SOME WOMEN have questions about the new birth control pills called Seasonale and Seasonique.

These pills work differently than most birth control pills, and cause fewer menstrual periods while being taken, which many women prefer.

Most birth control packets contain about 21 pills with one or more female hormones, and seven or less "blank" pills, without hormones. This is designed to produce "natural" cycle, and causes women to have their period during the monthly time of the "blank" pills.

Taking a pill every day (rather than stopping and starting) tends to minimize forgetting to take it.

The new birth control pills, Seasonale and Seasonique, cause women to have periods once every three months, instead of monthly. There is no buildup of toxins, and a period every three months is thought to be safe.

Menstruation is the result of a woman's egg-producing cycle that does not result in pregnancy. Each month the inner surface of the uterus becomes thicker in preparation for a pregnancy, and then sheds itself as the hormone levels drop at the end of the cycle.

This lets a woman know that she is not pregnant and prepares the uterus for the next cycle.

Birth control pills provide the female hormones, estrogen and progesterone - normally produced by the ovaries - fooling the ovaries into becoming inactive. This inactive state prevents pregnancy, and decreases the future risk of ovarian cancer.

Birth control pills most often fail because there is too long a time without hormone suppression, as when a woman forgets to take her pills. A woman becomes at risk of ovulating (producing an egg) if she goes more than eight days without the hormones in the birth control pills.

This occurs most frequently if there is a delay in starting the next month's packet immediately. A woman who stops taking the pills for seven days might forget to resume them right on time, whereas taking the pills regularly every day can become a useful habit.

Advantages of continuous hormonal levels as provided by Seasonale and Seasonique - without the "blank" pills - include decreased flow, less cramping and more effective contraception. Continuous hormones are also helpful in suppressing the condition called endometriosis.

Disadvantages of continuous birth control pills are that spotting (intermittent small amounts of vaginal bleeding) is more common, and the diagnosis of an unintended pregnancy may be delayed.

Doctors are also concerned that continuous birth control may raise some women's lifetime intake of female hormones, which may increase the risk of stroke and blood clots.

That risk goes up for women who smoke and are over age 35, or have other risk factors for cardiovascular disease, such as high cholesterol and obesity.

The best evidence we have suggests that continuous hormone pills are safe, but some side effects may become evident only after years of use. And many HMOs don't pay for these new pills, because they cost more than most birth control pills.

Women who prefer fewer periods along with contraception should discuss this option with their doctor.

Bliss practices obstetrics and gynecology at the Contra Costa Regional Medical Center in Martinez.