I recently got a comment on my Natural Family Planning entry, and I did a little reading to respond to it properly. My response was long enough, and sufficiently interesting, that I’m going to elevate it to full post status.
The comment I was replying to said:
I’ve done similar research and I agree that the whole Church’s case for NFP is unclear. But I think I can help you with the problem of the pill. I think that nowadays the crucial argument of the church against the pill is that it is an early abortive measure. Modern pills are too weak to guarantee that there is no ovulation. They have extra mechanisms of which one is to make a mucus barrier for the sperms, the other is changing the tissue of the uterus in such a way that a blastocyste (if it happens to be conceived) cannot root into it - so it dies and is expelled. If the last situation occurs, and if it occurs the couple is unaware - we can talk of an abortion (life begins at the conception). Further more - there is plenty of evidence that the hormonal pill (and blisters too) is harmfull to woman’s health and even life. Summing up, the pill is now forbidden not so much by the VI but by the V Commandment.
Here is my response:
I’ve heard similar arguments about the pill before—a friend of mine even went to a downright medieval pre-Canna (they were emphasizing how the woman had to obey and have sex whenever the man wanted) that made similar claims. I had written them off as off-their rocker, but I think the claim that modern pills are too weak doesn’t hold water for more reasons than that those fellows didn’t like it. Specifically, they have pills that can hold off your ovulation for three months at a time! One example is called Seasonale and is produced by Duramed Pharmaceuticals. If this pill was really too weak to guarantee that there is no ovulation, then it wouldn’t be able to hold off menstruation for three months at a time.
Now, I’m confident that there are side-effects to taking these pills. My understanding is that they consist primarily of a combination of estrogen and progestin (or synthetic varieties of the two, such as progesterone, norethindrone, or levonorgestrel as progestin replacements and estradiol or ethinyl estradiol as an estrogen replacement), and what these pills achieve is, essentially, fooling the body into thinking that it’s already pregnant and thus doesn’t have to release an egg. Different pills have different amounts and formulations (which is good if one pill has side-effects like making the woman’s breasts sore, because there’s hope that another formulation will not have that side-effect), but the general effect is the same. Even without the pill fertilized eggs are not guaranteed to implant—at least 15% of the fertilized eggs that humans create don’t implant for whatever reason (given how poorly designed our reproductive systems are, it’s astonishing that we’re as prolific as we are). Surely these cannot all be considered abortions. This is a natural function of the body: the uterine lining (the endomitrium) is normally unreceptive to implantation at the time of conception.
From what I have read (for example, on the website of the Association of Pro-Life Physicians), it seems that the evidence of this alleged abortofacient side-effect of the pill is exceedingly weak to begin with. The reason for this is, in part, because the pill is not the only actor in the hormonal system of the uterus: the corpus luteum, once the egg is fertilized, generates massive amounts of estrogen—ten to twenty times as much as is there normally—which causes a thickening of the lining of the uterus and prepares it for implantation. The evidence that pills are abortofacients (i.e. that they cause abortions) is based entirely on observing the uterine lining during a non-conceiving cycle and is merely an observation that the lining is not as thick as when the woman is not taking the hormone supplements, which then ties into observations from in-vitro fertilizations where thin uterine linings have lower success rates. However, given what the corpus luteum does when the egg is fertilized (releases massive amounts of hormones designed to make the uterine lining grow quickly), and given that it takes six days to travel from the fertilization point (within the fallopian tubes) to a point where it can implant in the uterus, it is entirely plausible if not certain that the uterine lining is returned to its full strength by the power of the corpus luteum’s hormone production.
A more thorough description is here.
There are other reasons for refuting the supposed abortofacient nature of these pills (and the Association of Pro-Life Physicians gets into them at length), but the ones above are the ones that convince me the most.
Thanks for commenting, though!
