Dear Doctor Column, June 5, 2006

Menstrual Periods Optional?

 Question:

I’ve heard there is a new birth control pill that stops your monthly period. Is this safe?

Using birth control pills to limit or eliminate monthly periods is not a new idea, but the practice is gaining wider acceptance among women and physicians. Some women, often those with endometriosis, painful cramps, or premenstrual syndrome, have suppressed their monthly periods for years by skipping the seven placebo pills in their 28-days packs, continuously taking the active-hormone pills.

In 2003, the Food and Drug Administration (FDA) approved Seasonale, an extended-cycle birth control pill limiting periods to just four per year. The pill proved popular, and a number of new products aimed at reducing or ending monthly menstruation are entering the market. The FDA recently approved Seasonique, another extended-cycle birth control pill. Unlike Seasonale, a birth-control regimen that includes 12 weeks of active-hormone pills followed by 7 days of placebo pills, Seasonique users skip the 7-day hormone-free interval at 3 months, instead taking a week of low-dose estrogen pills. The drug’s manufacturer expects the low dose of estrogen to reduce menstrual symptoms, including bloating and withdrawal bleeding.

The withdrawal bleeding experienced by most women taking oral contraceptives, including conventional pills taken in 28-day packs with 21 active pills and 7 placebo pills, mimics a true menstrual period, but is not the same.

Most birth control pills contain two synthetic hormones — estrogen and progestin. These hormones shut down ovarian function, preventing ovulation and thickening cervical mucus, which stops sperm from entering the uterus. The uterine lining, which grows thick each month in women not taking oral contraceptives and is shed during their period, stays thin in women on birth control pills. When active-hormone pills are replaced with placebos for 7 days, withdrawal from the hormones causes bleeding. Women taking birth control pills generally lose about two thirds less blood than women not taking oral contraceptives. They also often have fewer cramps and other problems linked to menstruation.

A pill designed to end periods altogether is poised to enter the market this summer. The FDA is expected to approve Lybrel, the first continuous-cycle birth control pill, in June. Lybrel does not include a placebo-pill interval, delivering low doses of estrogen and progestin 365 days a year. Studies evaluating the pill found that Lybrel’s suppression of monthly periods provides significant relief from the moodiness, irritability, and physical discomfort often associated with menstruation. Research also showed about one third of women had breakthrough bleeding, which grew less frequent the longer women took the pills. Several drug companies have products in development designed to stop or reduce monthly periods.

Many doctors think that blocking periods is no more risky than regular long-term use of conventional birth control pills. All oral contraceptives have side effects and hold some risks: serious complications are uncommon, but include life-threatening blood clots, stroke, and heart attack. Women who are older than 35 years and smoke have a higher risk of these side effects and should not take birth control pills.

New contraceptive options will likely make menstrual suppression more popular with women who would just as soon skip the monthly inconvenience of a period. But no one knows the long-term effects of continuous hormones. Again, many doctors believe they are safe, but others are cautious, noting that without long-term data, risks are unclear. The bottom line: talk to your gynecologist about new birth control options, including the risks and benefits.