Pregnancy and the Pill

Dear Mary Beth,

Thank you for your blog post about What the Church Really Teaches about Sex and Marriage. I have yet to see anyone mention the issue of contraception when it's required because of certain medications a person may be taking. Are you familiar with the medication, methotrexate?

That is an excellent question—one that isn’t addressed nearly as often as it should be. And I am happy to answer it.

Yes, I am familiar with methotrexate. And I’m glad you mentioned it, because it is a very interesting drug, and particularly useful for this discussion. Methotrexate is one of the primary drugs used in chemotherapy. It is also used in lower doses for rheumatoid arthritis and other chronic inflammatory conditions. And, finally, it is the “abortion drug,” given to women with ectopic pregnancies and those who wish to terminate healthy pregnancies.

Methotrexate, obviously, is very dangerous to unborn babies. That’s why they administer it to women who want to end their pregnancies. If the drug is ineffective, it generally leaves the baby with severe birth defects.  That is why contraception (generally the birth control pill) is “required” for women taking the medication.

I don’t think anyone would disagree that it would be a very, very bad idea for a woman to get pregnant while taking methotrexate. But let’s talk for a minute about why the “requirement” that they take birth control pills instead isn’t such a great idea either.

First of all, just because a woman is taking the pill, that doesn’t necessarily mean she won’t get pregnant. This is true in two ways. First of all, the pill has a failure rate. That simply means that it fails a certain percentage of the time. And “failure” is defined as a woman getting pregnant. Estimates of the Pill’s failure rate vary, but a quick Google search just gave me a range of between 6% and 9%—every year. When you think about how many women are taking the Pill, that adds up to a lot of pregnancies. The odds that some of those women are taking methotrexate are, I’m sure, not insignificant. Those babies will almost certainly either die or suffer significant birth defects.

But the deeper problem lies in the way the Pill works. It doesn’t necessarily prevent pregnancy. The old pills did a lot better job of that, but they had horrible side effects. The modern birth control pill (with slightly less horrible side effects) works on what is called the “triple threat.” First of all, it tries to prevent ovulation. But it’s not particularly good at this. So it also thickens a woman’s cervical mucus, making it more difficult (but not impossible) for the sperm to get to the egg. And, finally, it changes the lining of the uterus, so that the any newly conceived baby cannot receive the nourishment necessary to survive and grow, and thus dies.

This last action is not contraception, it is abortion. It is not preventing the baby from being conceived—rather it is allowing the baby to be conceived and then killing it.

Nobody knows for sure how often this abortive action happens among women taking the Pill, but I’ve seen estimates all the way from once or twice a year up to 50% of a woman’s cycles. I have no idea which is true. What I do know is that to continue to use the Pill— with or without Methotrexate—knowing that such an abortion is possible is to be complicit with that abortion when it happens.

So what is the answer for women on Methotrexate? Well, we all know that there is only one 100% effective way to prevent pregnancy, and that is to abstain from sex. Short of that, anything we do to prevent pregnancy will come with some risk of “failure,” and thus some statistical possibility of pregnancy.

Short answer: if birth control is “required” for you to take a particular medication, know that any birth control method will have a failure rate, which means if you’re taking it and having sex, you still stand a chance of getting pregnant. And, if you’re taking the Pill, you may very well be getting pregnant without knowing it.

I can’t see where there is any answer, aside from good old fashioned abstinence.

Do you have questions for Mary Beth?  Write to her at marybeth@catholicmatch.com.