Important Information About The Birth Control Pill

I haven't written alot of posts this week, because something came up on Wednesday that required some research and prayful consideration.

On Wednesday evening I was browsing through all of the new blog posts, and I came across a new post on my friend Amber's blog. If you'd like to read her post, check it out here.

Amber wrote saying that one of her friends had recently brought to her attention a fact about the birth control pill that she had not been previously aware of. She wrote that the pill works in three ways to prevent pregnancy:

1. Prevents ovulation (we all knew this one, right?)

2. Thickens the cervical fluid to make it difficult for the sperm to reach the egg.

These first two effects are contraceptive - they prevent conception, that is, the joining of the egg and the sperm. However, there is also a third effect that I had not heard of before.

3. Thins the lining of the uterus so that if an egg is fertilized, the feritilized egg will not be able to implant in the uterus. The fertilized egg would then die and be lost with the next menstrual cycle.

I am very pro-life, and I believe that life begins at conception. But this third effect means that the pill can cause a fertilized egg (which I believe to be a human being) to be lost. It's an abortive effect.

This information sent me reeling. I hadn't ever heard of this before, and I was pretty skeptical. I knew some methods of birth control, like IUDs (intra-uterine devices), caused fertilized eggs to be lost, but I had never heard of the birth control pill doing the same thing.

I'm very scientifically minded, so I decided to do some research on this before making a decision. Here's what I found out.

First I tried to find other resources that would give me information on whether or not this effect actually occurs, or whether it was just one of those theories that some anti-birth control person had come up with that didn't have alot of supporting evidence.

Every medical website that I checked listed all three effects of the pill. I checked out my specific birth control, and though the website for my birth control didn't list that third effect, it was confirmed to me by the other medical websites I checked that said low-dose hormonal birth control (which is what I take), does thin the lining of the uterus. I couldn't find one website that said that the pill does not thin the endometrium - every website either listed that as one of the effects, or didn't refer to it at all, but I couldn't find a source refuting it.

In addition, the statement that the lining of the uterus is thinned with hormonal birth control made sense to me. Don't most birth control pills broadcast that they can give you shorter, lighter periods? The lining of the uterus, or endometrium, is what is shed during your period, so if the period is lighter, the lining of the uterus must have been thinner.

I found a good paper on this topic written by a couple pro-life doctors, as well as an abbreviated version of the information in a book entitled Does the Birth Control Pill Cause Abortions? by Randy Alcorn. Please see resources 1 and 2 for links to those resources.

I was pretty disturbed by this information. I didn't want my birth control to have that effect. I like the pill - my periods were extremely irregular and heavy before I started the pill, and I liked the lighter periods and knowing when my period would be.

I wondered how often "break-through ovulation" occurs on the pill. I mean, the pill makes your cycles regular, and if ovulation almost never occurs on the pill, Derek and I could just guess the time that I would ovulate, if ovulation were to occur, and we could abstain during that period.

However, after a little more research I found out that in a study performed by Dr. Don Gambrell, JR. 4.7% of women on high dose birth control had breakthrough ovulation (meaning they ovulated even though they were on the pill), and 14% of women on low-dose birth control (50 mg or less) had breakthrough ovulation (see Resource 3). And apparently the only hormonal birth control that is really available today is of the low-dose variety. That means that you'll probably ovulate a couple times a year, even on the pill. If you ovulate and don't get pregnant, it's because one of the other two mechanisms kicked in. If the sperm never reached the egg, there's no problem, but if it did reach the egg and there was no pregnancy, then the egg was unable to implant and was lost.

What about staying on the pill and just trying to guess when you ovulate and abstain during that time? Unfortunately it seems that it is possible to ovulate any time during the month (see Resource 4). Even if you try to monitor ovulation through taking your basal body temperature or cervical mucous, those methods really can only tell you when ovulation has already occurred, or when it is imminent. In order to ensure that the egg isn't fertilized you have to stop having sex about seven days before ovulation, because sperm can survive for up to seven days inside the woman's body. I couldn't find a reliable way to predict ovulation that far in advance.

My conclusion from all this information hunting was that, yes, hormonal birth control of any kind (ring or pills) can prevent a fertilized egg from implanting, which, in effect, is very early abortion. Breakthrough ovulation can and does occur on hormonal birth control, and it is difficult to determine if and when ovulation occurs until after the fact, making the option of abstaining when ovulation is suspected to occur unreliable. *(Note: See update to this information after the Resources section.)

Update 8/2010: Since writing this post I have done alot more research on the signs of ovulation and how to predict ovulation in order to prevent , which appears to be alot more do-able than I originally thought. However, I still think it would be difficult to predict ovulation when taking the birth control pill, because of the additional hormones that the pill introduces to the body and the effects of those hormones on the quality and amount of cervical fluid (see the above list of the effects of the birth control pill). Changes in cervical fluid consistency must be observed in order to predict ovulation and prevent the fertilization of the egg. It would be very difficult to identify changes in cervical fluid when taking hormonal birth control because the pill causes a dry-up of cervical fluid, and that sign would then be obscured. Therefore, my previous concerns with adequately predicting ovulation when taking hormonal birth control are still valid.

I thought all you married, pro-lifers out there had a right to know this information. Each couple has to evaluate the information and decide for themselves. Hearing about this has resulted in a few restless nights, a ton of time spent researching, and quite a bit of prayer, but we finally came to a decision.

Knowing all this information, Derek and I could not justify continuing to use hormonal birth control. If the abortive effect of the hormonal birth control were to occur it would most likely be extremely rare, and may not even happen at all; however, there is a possibility it could happen, and there is no way to reliably prevent an egg from getting fertilized, should breakthrough ovulation occur.

If there is even a chance that a human life could be ended because of our choice to take birth control, can we really justify it? Derek and I couldn't. And believe me, I tried. I researched every avenue and excuse I could think of, but nothing can assure me that losing a fertilized egg won't happen. I really don't want to stop taking the pill - it makes my life so much easier and better, and I honestly don't think I'm ready to be a mother.

But do I want to answer to God someday for continuing to take the pill, even though I knew there was a possiblity that I could be losing babies by taking it? I don't want to be judged for that someday.

I believe every human life is precious, and I believe human life begins as soon as that sperm fuses with that egg. I have to try to do what is right, even though it's not what I want to do right now.

I prayed before I even began my research that the Lord would show us the right choice, that He would make the choices so clear that there wouldn't be a way that I could pick the wrong one. And I feel like He made His opinion on it pretty clear to me.

To be honest with you, I'm absolutely terrified! I don't want to get pregnant right now, and even though Derek and I have a pretty good plan for not getting pregnant, the chances are certainly higher that we might. But there was a fork in the road - choose my own way, follow my own desire and stay on the pill? Or do what I know is the right choice, take a leap of faith, stop taking the pill, and trust in the Lord to take care of us? If I really call myself a follower of Jesus, I have to choose the second. And I think my Jesus will continue to take care of me, whether we get pregnant right now or not. He's never let me down so far, and I really have no reason to believe He will now!

For a little more information on how we plan to try not to get pregnant, check out Resource 5 and 6. I'll do another post ASAP on our game plan, just in case any of you are interested.

My original post stopped here, but another question was brought up in the comments section which I spent some more time researching. My response and conclusions are below.

Brittany, my dear blogging friend, brought up a point in the comments section that referred to how some doctors think the research is inconclusive on whether the thickness of the endometrium in pill-users can cause fertilized eggs to be lost. So yes, I did more research! Here's some more stuff I found out.

I did a little more research on why some doctors think the research is inconclusive for the third effect. I found a research paper (see Resource 7) that stated that some doctors think that if breakthrough ovulation does occur in women who are taking birth control, the associated increase in estrogen will help to thicken the lining of the uterus at that time. There are no studies that show that the endometrium does thicken after breakthrough ovulation, but there's no studies that show that it doesn't either. That's why some pro-life doctors are okay with birth control, because there hasn't been a study done to see what the endometrial thickness is in women on birth control after breakthrough ovulation.

I did a little more research on the average pre-ovulatory endometrial thickness in women who are not on birth control. If the difference in thickness between women who are in the pre-ovulatory phase and women on birth control is pretty significant, that would be some information that I would consider helpful in my own decision-making process.

The average pre-ovulatory endometrial thickness in women who are not on birth control is anywhere from 3-8 mm (I found one page that said it could be 3 mm, but I lost that page - one resource I found says 4-8 mm usually before ovulation - see Resource 8). In the ovulatory phase (right before and after ovulation) it is usually 6-10 mm thick, and post-ovulation it increases again to anywhere from 7-14 mm thick.

I found a study (see resource 9) that measured the uterine thickness in pill users and non-pill users, and concluded that "Endometrial thickness was significantly smaller in the pill-using group, correlating with the well established fact that oral contraceptives cause atrophy of the endometrium". "In the pill-using group, endometrial thickness was 1.1 mm in both phases . . ."

In women on birth control the thickness starts out at about a third of the thickness of the lowest number I could find in a pre-ovulatory, non-birth control estimate (1.1 mm compared to 3 mm). The minimum thickness for implantation to occur can be anywhere from 5 mm to 9 mm to 13 mm (see Resource 1 again).

Since the thickness starts out so much thinner, and stays that way throughout both phases of the cycle, it seems to me that it would be questionable whether it would increase in thickness to the point that it could support implantation after breakthrough ovulation, if the thickness increases at all (remember there are still no studies on what happens after breakthrough ovulation on oral contraceptives).

The third effect of birth control seems to be pretty well accepted in the secular community (and why shouldn't they accept the evidence as it is - it doesn't affect their belief system like it does ours). The debate on whether that third effect does indeed happen seems to be mostly within the pro-life community - because it affects our pro-life belief system so much, I think it's harder for us pro-life people to be totally objective on this. But the secular community can be pretty objective, because they don't care if it inhibits implantation or not. I think more research should be done on the thickness of the endometrium in pill users after breakthrough ovulation. Until more studies are done, there is just no way to be sure what exactly happens.

I think the secular community to be more objective (as much as it pains me to admit that) on this topic because of their lack of belief that they need to change their behaviour depending on whether or not the third effect happens. So I'm going to go with the thought of the group that I would think to be a little more objective on this issue, until more research is done.

1. Larimore, Walter L.; MD. Stanford, Joseph B.; MD. "Post fertilization Effects of Birth Control and Their Relationship to Informed Consent." Arch Fam Med. 2000;9:126-133. Link:

2. Alcorn, Randy. "A Condensation of Does the Birth Control Pill Cause Abortions?" Link:

3. Schibler, Ann. "Growing debate over abortifacients: abortifacients, drugs or agents that cause an abortion, are commonly sold to women who think they are getting substances that prevent conception altogether." The New American, January 21, 2008. Link:

4. Grunebaum, Amos; MD. "Ovulation Issues", MedicineNet, WebMD Live Events Transcript, February 2, 2004. Link:
"Member question: Is it possible to ovulate the day after you stop bleeding?

Dr. Amos: It is possible to ovulate any time in your cycle, even the day after you stop bleeding. Most women usually ovulate around CD 14 or so, but much earlier and much later ovulations are possible."

5. A website on information on pregnancy. Check out this link for some good information on how to prevent pregnancy when you are not on the pill. Link:

6.'s Fertility Chart. Link:

7. Johnston, James P; D.O. "Do Oral Contraceptives Cause Abortions?" Updated january 7, 2005. Link:

8. Daiter, Eric; MD. The New Jersey Infertility Treatment Center. "Procedures Tutorials" page. Link:

9. McCarthy, Shirley; MD, PhD. Tauber, Cheryl; RT. Gore, John; PhD. "Female Pelvic anatomy; MR Assessment of Variations During the Menstrual Cycle With Use of Oral Contraceptives". Radiology, Volume 160, Number 1. 1986. Link:

*Update 8/2010: Since writing this post I have done alot more research on the signs of ovulation and how to predict ovulation in order to prevent or achieve pregnancy (see the post "The Fertility Awareness Method" for more information). Predicting ovulation appears to be alot more do-able than I originally thought.

However, I still think it would be difficult to predict ovulation when taking the birth control pill, because of the additional hormones that the pill introduces to the body and the effects of those hormones on the quality and amount of cervical fluid (see the above list of the effects of the birth control pill).

Changes in cervical fluid consistency must be observed in order to accurately predict ovulation and prevent the fertilization of the egg. Hormonal birth control causes a dry-up of cervical fluid. It would be very difficult to predict ovulation by identifying changes in cervical fluid when taking hormonal birth control, because that sign would be obscured as an effect of the pill. Therefore, my previous concerns with adequately predicting ovulation when taking hormonal birth control are still valid.
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Jenene said...

Wow. Thank you for being so honest about this. Tricky topic. I don't think I could ever write about this on my blog. Good on ya! (As Australians like to say).

I am not on the pill. 1) I didn't like the idea of artificially controlling my hormones like that. I'm quite wary of pills of any kind, and though they are sometimes necessary, the idea of the pill didn't sit right with me.

2) I have heard of a few people (friends, or friends of friends) who got pregnant, didn't know it, kept taking the pill, and then had a miscarriage. I think it's possible eve to abort eggs that HAVE planted themselves to the uterus.

3) When Art was a few years younger (in his late teens), he dated a couple of girls who were on the pill (not b/c they were sexually active, at least not with him) and he said their moods were all over the place. He begged me not to go on it, and I didn't want to anyway.

4) My periods are regular, and not too heavy. I am very sorry that your periods are worse, b/c THAT is a good reason to justify taking the pill. I will definitely pray that God will heal that area so that you don't have to suffer and regret going off the pill.

Art and I also us the "rhythm method", and so far it's worked. I try my best to figure out which day ovulation might occur, and then account for the 6 "risk days" before and after.

But to each their own. I'm glad that have taken this to God in prayer, and that you are willing to obey. It's a tough decision, but I pray that God will bless you b/c of your obedience.

And sorry for the really long comment. :)

Jenene said...

Oh, and one more thing. I know this is kind of shocking, and you might not believe me, but if you research the origins of birth control and Planned Parenthood, you'll find out that it was first invented to be given to poor people, so that they wouldn't reproduce, so that eventually, the "race" of poor people would die out.

Check out the movie Expelled by Eugene Levy. It's mostly about the farce of evolution, but it talks about the pill a little bit (the idea of weeding out poor people comes from a Darwinian way of thinking. Same one that Hitler used.)

Callie said...

Thanks for your prayers about my cycles, Jenene! That means alot. That, honestly, is the biggest reason I'm so concerned about going off the pill, because it's going to be kind of hard to guess when I ovulate if my cycles are as irregular as they were before. And I had awful cramps and my periods lasted for about seven days . . . it is just not fun. My PMS symptoms have actually been better since I've been on the pill then when I was off it (including the emotional symptoms). So yeah, I am definitely in need of prayer!

I have heard of the whole eugenics movement being connected to planned parenthood, and it doesn't surprise me that the pill was a result of that. Isn't it deplorable how they want to just kill off certain people groups like that? I actually heard that the lady who started Planned Parenthood actually hates black people, and they have funding specifically for abortions for African Americans. It's pretty disturbing stuff.

You're talking about Expelled with Ben Stein right? I love that movie! Derek and I actually own it, if that's the one you're talking about. IU didn't remember anything about the pill in it though, so maybe you're talking about something different.

Brittney Galloway said...

Great Post! We found out about that #3 about a month after we got married, when I heard a sermon from Mark Driscoll (in Seattle.) I was heavily convicted as well, but I was also convicted by part of the sermon that goes on to say it is also wrong to bring a child into this world when you have absolutely no means of providing for them (ie food, clothing, health care.) Not that he was justifying #3 of a birth control pill, but he was saying that all of the research on #3 is inconclusive. They THINK that is what is happening/causes it. Even Focus on the Family was quoted on how inconclusive the evidence on #3 was. Funny how some research sites make it sound like they absolutely have the answer when it is still in the research pipeline.

Callie said...

Hey Brittany!
Yeah, I found Dr. Dobson's statement on his position on birth control, and he said if it does indeed have the third effect then it would present a problem to pro-life individuals. Alot of the doctors he talked to thought that it didn't have an abortifacient effect, but he said they would be following the research on it. That was back in 1999. I couldn't find any more recent statements on it from FOTF.
My big problem was that I couldn't find any sources that said the research was inconclusive, but I did find a resource sheet from Focus on the Family about this that said there are only two studies that are against the abortifacient effects of hormonal birth control. Apparently the rest seem to confirm it.
If you have any resources that bring into question that third effect, I would be interested in seeing them. I still feel like even if the research is inconclusive (which like I said, most of the resources I could find confirmed that third effect or just didn't mention it), but there is a significant chance that a fertilized egg could be lost, I can't in good conscience continue to use it.

Jenene said...

Sorry, yeah, Ben Stein. I was thinking of the right guy, I just got his name wrong. And I don't know if the movie mentioned the pill, but it mentioned Planned Parenthood, and the pill is one "branch" of their

Amber said...

Good post, Callie. It's going to be hard for us too, but I know it's the right decision for us as well. Another thing that I read somewhere (and this was one thing that really convinced me) was that you can take multiple birth control pills at once in place of the "Plan B" (emergency contraceptive). I'm sad that I have to stop too. My body is the exact same way. I might not have a period for 50 days, or I might only go two weeks before I get another one. And mine are bad as well. So I'm not looking forward to that (I've been on it for 3 1/2 years trying to regulate my cycle). But God knows my intentions are pure, and I am praying that He'll bless me for wanting to do the right thing and help my body regulate itself. Hopefully we don't end up preggo in six months!

Unknown said...

Thank you for sharing this. I had not heard of this before.

I hope that eventually you will feel settled with your decision because whatever the outcome one day you are going to make a fantastic Mum for taking this decision. Although the risks are higher the rewards are greater :)

Callie said...

I did a little more research guys, because I was wondering why some doctors think the research is inconclusive on whether that third effect happens. Please check out my addition to this post!

Lydia said...

I have spent about ten hours researching this myself. I'm getting married soon and am attempting to make the decision about birth control.

You may or may not find it reassuring that I have come to all the exact same conclusions you have. I think until a study measures whether the endometrium thickens after breakthrough ovulation on the pill, we just can't know for sure.

I'm going to keep searching a bit longer, but I'm thinking the pill is out for me. My fiance and I had talked about what you and your husband did with abstaining or using protection when breakthrough ovulation might occur on the pill, and it was hard to find information about when that might be. It also sounds to me that it could be anytime. So that might mean no pill for us.

Lydia said...

Update: After more hours of searching, including looking through a scientific database, I talked more with my fiance. He said that, approaching the topic scientifically, there is no conclusive evidence either way, which is not a basis for prescribing action. Another important issue was the amount of concern and worry that not being on the pill would bring into our future marriage. For me, I have decided the best option is to be sensitive to his desires and leadership and try the pill.

Because there is no conclusive evidence about breakthrough ovulatory cycles, this whole issue especially is a personal decision for each couple before God.

Prayers and best wishes for all who are on this trail too. =)

Callie said...

Hi Lydia, I appreciate you sharing your thoughts on this. However, just to clarify for those reading, the area of this issue that has not been proven or disproven is whether break-through ovulation has an affect on the thickness of the endometrium while on the pill. There is much scientific evidence that the pill does indeed thin the lining of the uterus (endometrium) to levels that cannot support implantation in a non-breakthrough-ovulation cycle on the pill. It's listed as an established effect of the birth control pill. You are right that we can't know for sure at this time if the endometrium will reliably thicken enough to support a fertilized egg after ovulation if a woman were to conceive on the pill. It may, it may not,

Honestly, it likely varies woman to woman, since some people do get pregnant on the pill, but it's always going to be impossible to know if/how many babies may be lost before implantation because of this effect. We can only go off of the available evidence and the risks, and medically speaking, the risk of something happening is actually a reason to prescribe action. This happens all of the time. It becomes especially obvious when you do get pregnant and have children...there are all sorts of things we avoid during pregnancy, even though adverse effects in humans haven't been absolutely proven, because peripheral evidence leads doctors to believe there is a risk for an adverse effect. It's the same reason some parents choose to avoid vaccines, because there is enough peripheral evidence to lead them to believe there is a risk.

Hope you don't mind my inserting my opinion here, but then again, it is my blog! The bottom line is that we can debate probabilities, but there is a pretty universally recognized evidence for a risk of implantation being prevented as the result of the pill. There isn't enough research at this time to prove how much of a risk that is, just enough to know the possibility is there. The reason I wrote this post is because I wanted my fellow pro-life Christians to just know there is a risk there so they can pray about it and weigh it. For us, the possible risk of preventing a baby from implanting after conception was concerning enough that we didn't feel we could continue with it in good conscience. And I'm glad we didn't, or we wouldn't have the children we do now, since it took almost a full year for my cycles to return after we went off the pill. It was actually the Lord convicting us to go off the pill as much as our pro-life views, and I'm thankful we listened to His prompting.

Anyway, I'm not trying to change your mind necessarily at this point, just trying to provide my take on the risks for anyone reading this comment thread in the future, and also to encourage fervent prayer on this for those Christians who think the Holy Spirit might be convicting them too. Science can only take you so far. As I said in my original post, it is something that each pro-life Christian couple needs to pray about, seek the Lord's will for their future, and make their own decision. Thanks for the comment, and good luck to you and your fiancé!

Callie said...

I recently got some criticism for the above comment about Margaret Sanger and PP's eugenics origins, for not providing a source - this page provides plenty of supporting information for what I originally mentioned in the comment above in passing eight years ago, including videos of PP being more than willing to accept money designated for racial minority group abortions. To the person who left the recent critical comments, if you feel the need to respond, please be civil. I am more than willing to have a courteous discussion, but I won't allow insulting or nasty comments on my page. Thanks!

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