Once-a-month contraceptive pill is scientifically possible, say experts

http://www.theguardian.com/society/2013/sep/23/once-month-contraceptive-pill-possible

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A contraceptive tablet that acts like the morning-after pill but could be taken up to a month after sex is probably scientifically possible and would be welcomed by women, scientists have said.

But the authors of a paper in a leading medical journal say efforts to get such a pill on the market could falter because of the political controversy likely to be kicked up by opponents of abortion.

The authors of the paper in the Journal of Family Planning and Reproductive Health Care, part of the British Medical Journal group, would like to see funding for exploratory work on a post-sex pill, which they anticipate would be similar to the morning-after pill but used routinely and potentially as rarely as once a month or only after the woman has missed a period. The morning-after pill has to be taken within 72 hours of unprotected sex.

"A woman could potentially use a postfertilisation method on a planned schedule only once in each menstrual cycle, no matter how many prior coital acts she had had in that cycle," wrote the experts from the US and Sweden.

"If the drug were effective when administered after implantation of an embryo, timing would be flexible, and she might even be able to limit its use on average to a few times a year when her menstrual period was late. Importantly, post-fertilisation methods would eliminate the conceptual and logistical challenge of needing to obtain and initiate contraception before having sex, which can be daunting for both women and men."

But controversy is inevitable, they say. Pregnancy is defined in the UK and US as occurring when the fertilised egg implants in the uterus. Some people are uncomfortable even with contraceptive methods that prevent implantation of a fertilised egg, the authors say, but interrupting the course of a pregnancy after implantation "is abortion by any definition".

Abortion is legal in the UK, the US and elsewhere and is safer the earlier in the pregnancy it is carried out. Nearly a third of women in England and Wales and the US will have an abortion in their lifetime.

The article says some contraception methods currently in use probably act after fertilisation, at least in part. The IUD – internal uterine device or coil – prevents pregnancy in the womb but not always ectopic pregnancy in the fallopian tube. That suggests, they say, it may work by preventing the fertilised egg implanting in the uterus.

Existing hormonal contraception methods may in the long term affect the lining of the womb, reducing the chances of fertilised eggs implanting. And while the morning-after pill generally prevents ovulation, one version contains the drug mifepristone, which also has a use in abortion.

Dr Elizabeth Raymond of Gynuity Health Projects in New York, the lead author, said one concern she and her colleagues shared in writing the paper was publicising the post-fertilisation effects of some of the current contraceptive methods, for fear of causing unwelcome controversy.

"The family planning advocacy community has not wanted to really talk about that very much because it could raise concerns about those contraceptives as well and that could be a problem," she said.

"But we feel we need to be open and start really talking about how the current methods really work and how this future method could work if we could develop it. Overall, that will help us make progress. Sunlight is the best disinfectant."

Pharmaceutical companies have not always been innovative in this field, she said. Many new developments, such as the contraceptive implant and the female condom, came originally from non-profit research groups.

"This has been a problem for a long time," she said. "With this particular method there is the additional particular issue of concerns about abortion."

Not every woman wants to take daily pills, she said, especially if they are not regularly having sex. "Many women are not satisfied by the currently available methods."

There is limited evidence from surveys that some women would like to be able to take a pill less frequently, even if it is post-fertilisation, she said.

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