RENEE MONTAGNE, host:
This is MORNING EDITION from NPR News. I'm Renee Montagne. In your health today, women and birth control.
Among women who use birth control pills, there's growing popularity for what's called continuous contraception - taking birth control hormones every day of the month to eliminate menstrual periods for three months, four months, even a year or more.
NPR's Patricia Neighmond reports.
PATRICIA NEIGHMOND reporting:
Heidi Matari is 28-years-old, lives in Seattle, is single and works in health research.
Ms. HEIDI MATARI (Health Researcher, Seattle): You take your normal pack of birth control pills, which has 21 active pills in it and then normally you would take the seven spacer pills afterwards. So I just throw out those spacer pills and start a new pack.
NEIGHMOND: And the next month, Matari does the same thing. She's been doing this for about six years. Not only is it effective birth control, but it's reduced the uncomfortable symptoms - cramps, bloating and feeling sick - that accompanied her monthly periods.
Matari says she doesn't miss that at all.
Ms. MATARI: I do hear that kind of talk, like, you're supposed to be missing, but realistically, I don't. I don't miss it at all. I mean, I don't think I ever really enjoyed getting my period before, so I don't miss it now.
(Soundbite of doctor speaking to patient)
Dr. LESLEY MILLER (OB/GYN, Harborview Medical Center): ...and take your blood pressure. How've you been doing?
NEIGHMOND: Dr. Lesley Miller is an OB/GYN at Seattle's Harborview Medical Center. Matari used to be one of her patients. Dr. Miller says more and more of her patients are taking birth control hormones without a break.
Dr. MILLER: When a woman then uses something like the birth control pill, every day becomes the same, hormonally. She has a set dose of progestin and a set dose of estrogen. She takes the pill, those hormones are absorbed, there's a maximum blood level within 1-2 hours, it then begins to fall and by 12 hours, there's a nadir, a very low level of these two hormones. And by 24 hours, she needs another pill.
NEIGHMOND: And if hormone production is lowered every day, then there's no build up of the uterine lining, and therefore no need to shed it. When women are on traditional 21 days on/7 days off birth control, monthly periods are artificial anyway, says endocrinologist Sheldon Segal, a long-time contraceptive researcher at New York's Population Council.
Artificial, because they're not sending an unfertilized egg along with the uterine lining. They're just bleeding and monthly bleeding, says Segal, was actually a marketing decision made decades ago when the pill was first developed.
Mr. SHELDON SEGAL (Endocrinologist, New York Population Control): Their marketers felt, at that time, that an oral contraceptive might or might be accepted by the public. Those were different times you have to remember.
NEIGHMOND: Taking away ovulation was already a big change, says Segal. It might be too much to also take away monthly periods.
Mr. SEGAL: You have to remember, also, that this was a time that was before the drugstore pregnancy tests. So that if a woman was not bleeding or not having a regular menstrual period, she wouldn't know whether she was pregnant or not. There would be an anxiety about unintended pregnancy.
So that was another reason why the marketer felt that it would be better to have a one-week off period to allow this artificial menses to occur.
NEIGHMOND: Ironically, Segal says, it's not all that natural to menstruate as much as women do today anyway. The average American woman has 450 periods during her lifetime. In early human history, he says, women menstruated a lot less.
Mr. SEGAL: The usual pattern was for a young woman, young female, moving around in Nomadic tribes, always exposed to males, to become pregnant as soon as she showed the first signs of sexual maturity in the menarche. And then being either pregnant or lactating for the rest of her life.
NEIGHMOND: Dr. Kirtly Parker Jones is an OB/GYN at the University of Utah. Jones says that for years women physicians have controlled their own menstruation.
Dr. KIRTLY PARKER JONES (OB/GYN, University of Utah): In fact, I just did an exam for a female OB/GYN physician today and I asked her when her last period was and she said, I don't know. Three years. I only have periods when I want to get pregnant.
NEIGHMOND: And when women stop the pills to get pregnant, Jones says fertility returns pretty quickly.
Dr. JONES: Ninety percent of them are pregnant within one year, and about 50 percent of them are pregnant in six months. And most people are back achieving some pregnancies in the first two months after pills.
NEIGHMOND: Jones says taking birth controls continuously, carries the same risks as taking them for 21 days with a seven-day break. In rare instances, women suffer blood clots, stroke, or heart attack. Controlled studies have looked only at one year of continuous contraception, and showed no increased risks. Jones says big, multi-year studies probably aren't feasible because women taking part would have to promise not to get pregnant for three, five, even 10 years. Jones says there's powerful evidence from years of experience with patients on 21-day pill cycles, that suggests continuous birth control is also safe.
Dr. JONES: Remember, we've had pills for 40 years, and remember that we - that millions, and millions, for at any given time, about 30 percent of women of reproductive years, are taking hormonal conception. So, 30 percent of what might be 50 million women ends, up being about 15 million women times 40 years, is a lot of information.
NEIGHMOND: Long-term research on 21-day birth control regimens show hormonal contraception is highly protective against uterine and ovarian cancers. Less is known about breast cancer, but Jones says early data from women now in their 60s, who took the pill during their reproductive years, indicates no increased risk of breast cancer later in life. The FDA is expected to decide within a month, on an application from Wyeth Pharmaceuticals, to market the first oral contraception intended to be taken every day of the month.
Patricia Neighmond, NPR News.
NPR transcripts are created on a rush deadline by Verb8tm, Inc., an NPR contractor, and produced using a proprietary transcription process developed with NPR. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.