Birth Control

    Today's IUD's typically use a plastic T-shaped frame about 1¼" across and 1½" high with a small string on the base, and with copper or gold wrapped around the stem of this frame. The metal dissolves very slowly, and slow-release progestogen may be added as well.CDC These are spermicides with two functions - first to curtail the ability of sperm to swim in the cervical mucus thus blocking entry, or for sperm that do make it into the uterus, to terminate them before they can pass up a eustachian tube to the normal site of fertilization. Non-hormonal IUD's prevent implantation. Standard spermicide-hormonal IUD's prevent fertilization.

    These IUDs put ions or hormone where they are functionally needed, not into systemic circulation, thus avoiding several problems caused by regular birth control pills. And in spite of the anomalous Dalkon Shield, IUD's have proved very safe for long-term use. They can also be used as "morning-after" treatment, and the non-hormonal form is compatible with breast feeding. The hormonal form of IUD is highly effective for up to seven years. Initial cost is high, but average cost is low.

    Birth control pills contain estrogen and/or progestin, and their primary mode of action is to prevent egg formation and ovulation. They also alter cervical mucus making passage by sperm unlikely. So there is nothing to fertilize and usually nothing to do a fertilization. If a women is erratic about following the daily schedule of pills, though, she might ovulate and have a fertilization, in which case the birth control pills may block implantation of an embryo. The pills are far too weak to abort a fetus or cause separation of a placenta from the uterine lining.   [The historic Catholic reason for not taking birth control pills is not avoidance of abortion as some claim.(see "Issues / Some Catholic History")]

    A better reason for not taking birth control pills is their side effects and times of poor reliability. Perhaps as many as a third of women can not tolerate them, side effects sometimes including cysts on the ovaries or in the breasts and on rare occasions blood clots or even fluid over-pressure in the brain. The pills commonly cause loss of sexual interest after about five months of use. And doctors commonly forget to advise, even for single women, that birth control pills stop working during and following antibiotics. Protection does not resume until a wait time after the antibiotics that is as long as the duration of taking the antibiotics. Three weeks of antibiotics, for instance, means no protection for six weeks.

    Natural birth control during lactation relies on similar hormones and has the same caveat. A women who provides all the nutrition for her child will not ovulate, not if she nurses every four hours during the day and every six hours at night. But as the child matures and she provides less, or perhaps even if she uses pumping instead of direct breast feeding, she will begin ovulating again. And she may have a fertilization she never notices, because with partial nursing, her partial supply of natural hormones may allow ovulation but prevent implantation.

Morning After Pills

    Emergency contraceptive pills or ECP's are intended for one time use. There are two types - Plan B offering pregnancy prevention if taken within three days after intercourse, and EllaOne offering about the same 60% effectiveness but after as many as five days.   Plan B is the more benign and most unlike the abortion pill, Ru-486.

    The primary modes of action of the Plan B morning after pill are to prevent ovulation and hence fertilization and to induce shedding of the uterine lining and hence prevent implantation if a fertilized egg should arrive. A Plan B pill is essentially the same chemically as several standard birth control pills combined into a higher dose for one-time use. It contains the same estrogen and/or progestin hormones and is still low enough dose not to abort an embryo that is already implanted.

    The EllaOne morning after pills are very different. They do not contain hormones but instead block hormone action, and specifically block the receptors for progesterone. They use a compound similar to Ru486 at 1/20th the dose level. This is not designed to prevent egg formation or ovulation or to induce abortion of an established fetus, but instead prevents implantation and may cause separation of a newly implanted blastocyst. At the time of approval in the U.S., data from test trials are not sufficient to establish for sure whether EllaOne might or might not sometimes cause established fetus separation or birth defects, or whether it should be avoided when breast feeding. It is clear, though, that some women who become pregnant even after taking EllaOne do have a small chance of miscarriage or induced abortion.

Abortion Pill

    Ru-486 is an abortion pill containing a high 600 mg dose of Mifepristone which is then followed two days later by 0.4 mg misoprostol to induce contractions. Birth control and Plan B morning after pills are very different and do not induce abortion.

    A lot depends on dose level. At 2 mg/day, Mifepristone is just a standard oral contraceptive preventing ovulation, and at 1 mg/day it doesn't even do that. The dose level required to cause separation of the placenta from the uterus and opening of the cervix is 600 mg. The combination with contraction-inducing misoprostol terminates 96 to 99% of pregnancies at up to 49 days gestation. Mifepristone is marketed under trade names Mifegyne and Mifeprex, and the product sold in the United States is made in China. Mifepristone functions by blocking progesterone receptors. The single high dose does not prevent egg formation or ovulation or alter cervical mucus like standard birth control pills. EllaOne pills contain 30 mg of ulipristal acetate (trade name Ellaone, HRA Pharma) and are not followed with anything to induce contractions.