Plan B Not Abortifacient, But Doesn't Change Much, Either

As the news that the FDA may soon make Plan B , the progesterone only protocol that is often called "Emergency Contraception" or the "morning after pill," available without prescription, we'll probably hear all sorts of opinions about whether or not it is an abortifacient or will lower the abortion rate.

The answer is probably "no" for both.

There is good news about the Plan B protocols, the progesterone-only formulations. The evidence is not conclusive, but I am fairly convinced that the protocols only work before ovulation and any effect after ovulation would serve to slow the sperm so that it's less likely to get to the oocyte in the fallopian tube, where fertilization takes place and to actually *encourage* implantation if there is fertilization.

This latter makes sense when we remember that one of the reasons for miscarriage is low progesterone and fertility docs often give
progesterone to women early in pregnancy.

It is very important to spread the news that if the pill only works by blocking ovulation, it will only work - and is only useful- during the 5 days or so before ovulation. (Fortunately, that's the most fertile period of the cycle, too.)


The most significant information about the mechanism by which the Levonorgestrel-only medicines function are the studies from Brazil by Croxatto and his group (H.B. Croxatto et al. Contraception 70 (2004) 442–450), which was a blind study, cycling women who were otherwise unable to get pregnant (sterilized or with - what I consider unethical and potentially abortifacient - IUD's) through 3 courses - placebo, and two forms of progesterone-only pills. The researchers followed the women with serial ultrasound and hormonal blood essays of hormone levels. The levonorgestrel interupted ovulation, so there could be no fertilization and no lost pregnancies.

There is a supporting study by Durand, et.al. (M. Durand et al. Contraception 71 (2005) 451– 457), from 2001 which tested surgically sterilized women given 2 doses of Levonorgestrel, 12 hours apart. These women were studied by serial ultrasounds and women who ovulated also underwent endometrial biopsy. There was no difference in their uterine lining function or anatomy although there was a difference in the expression ofglycodelin-A. This protein prevents binding of the sperm to the zona pellucida of the oocyte and so, prevents fertilization. (There is some speculation that the protein acts to help implantation, too.)

The conclusions from the data are still controversial. I am not one to risk causing death until I am certain, so I hope that Croxatto and Durand will continue their research and that others will replicate it.

On the other hand, results from other countries indicate that the abortion rate will not come down with increased access to Plan B. In fact, women and girls who were provided with the morning after pill in advance were no more likely to use the medication than before and were no more and no less likely to have unprotected sex.

From the British Medical Journal:

After emergency hormonal contraception was made available over the counter, levels of use of different types of contraception by women aged 16-49 remained similar. No significant change occurred in the proportion of women using emergency hormonal contraception (8.4% in 2000, 7.9% in 2001, 7.2% in 2002) or having unprotected sex. A change did, however, occur in where women obtained emergency hormonal contraception; a smaller proportion of women obtained emergency hormonal contraception from physicians and a greater proportion bought it over the counter. No significant change occurred in the proportion of women using more reliable methods of contraception, such as the oral contraceptive pill, or in the proportion of women using emergency hormonal contraception more than once during a year.

From Medical News Today, a fairly reliable source for medicine news, is this story from December 2004;

Morning after pill fails to reduce abortion rates
04 Dec 2004

The decision to provide women with the morning after pill over the counter has failed to reduce the UK's abortion rate, new figures reveal.

Researchers from Dundee, Edinburgh and Oxford universities found that a 28-month scheme by Lothian Health Board had no effect on women who were not already using family planning services.

Nearly 18,000 women aged from 16 to 29 were given packs of the morning-after pill to keep at home under the scheme.

However, the study concluded that many people were "too embarrassed" to ask for the advance emergency contraception.

More than 4,500 of the women gave at least one course to a friend and 45 per cent of the women used at least one of the courses themselves during the study, but admitted that they rarely asked for advance supplies of emergency contraception due to embarrassment and concern about being judged by health professionals as morally inadequate.

(Please note the fact that women gave these pills to other women and girls.)

What will change is that there will be less of a chance for a woman or a girl to have personalized medical advice or any sort of examination for the other problems that come from unprotected sex.