If a pregnant woman took birth control, what would happen to the fetus?

January 6, 2006 7:54 AM

If a woman on birth control pills became pregnant, but continued to take the pills, what would happen to the fetus, if anything? This is idle curiosity - I'm not asking for a personal situation at all.
posted by agregoli to health & fitness (12 comments total)

From this page:

If you continued taking your birth control pill because you didn't realize you were pregnant, don't be alarmed. Despite years of this accident happening, there's very little evidence that exposure to the hormones in birth control pills causes birth defects.
posted by dead_ at 7:57 AM on January 6, 2006

But it also says:

Still, the birth control pill is a potent estrogen. Lessons learned from women who took diethylstilbestrol — a synthetic estrogen that was later linked with cancer — to prevent miscarriage in early pregnancy suggest that such exposure should be minimized.

Once you learn that you're pregnant, stop taking the birth control pill.

What would happen if a woman took them all throughout her pregnancy? I've been searching, since I'm sure someone has done this, but can't really find much.
posted by agregoli at 8:17 AM on January 6, 2006

I'm trying to remember my brain chem. class, but I believe estrogen and testosterone are processed in strange ways by babies. IIRC, estrogen is metabolized into testosterone inside the cells, so I would imagine that extra estrogen would actually cause more manly babies?

Balancing the hormones a fetus gets is very important, and different doses can cause huge differences in personality types and phenotypes. A lot of what people consider 'genetic' differences are actually prenatal differences caused by all sorts of stuff.

It's best to avoid doing anything funky with your biochemistry while pregnant, IMO. However, there is of course a lot of difference between hormone levels in different women, so taking birth control while pregnant probably wouldn't create a baby outside of the norm, but they might be different personality wise then they might otherwise have been.
posted by delmoi at 9:05 AM on January 6, 2006

I've wondered this myself.

I thought that BCP trick your body into thinking it is pregnant, so therefore it wouldn't do any damage.

However, they say that the morning after pill is just like 4 regular BCP in one dose.
posted by k8t at 9:43 AM on January 6, 2006

as far as the hormonal effects go, this recent article could pertain: link
sounds like delmoi is right on, hormones have a pretty huge impact on babies.
posted by tysiva at 9:49 AM on January 6, 2006

I don't know about taking it all through pregnancy but I am familiar with at least one case of someone who got pregnant on the pill and the resulting child turned out perfect.
posted by Doohickie at 10:42 AM on January 6, 2006

Yes, yes, lots of people get pregnant on the pill.

I'm interested in what would happen to the fetus if the pregnancy was in paralell with birth control pill-taking throughout.
posted by agregoli at 10:45 AM on January 6, 2006

I thought that BCP trick your body into thinking it is pregnant, so therefore it wouldn't do any damage.

From what I understand (i.e., what my doctor told me), the pill does 3 things:
- stops you from ovulating
- thickens the mucous around the cervix, so on the off-chance that you do ovulate, the sperm have a lower chance of getting through
- thins the uterine lining, so eggs have a lower chance of sticking around

So, it seems like if you were to get pregnant, the physical effects of the pill wouldn't do any harm. The hormones are another thing, and I have no idea what effect they'd have.
posted by rachelv at 11:08 AM on January 6, 2006

delmoi, other way around: testosterone gets aromatized into estradiol (main type of estrogen). but in the brain, anyways, estradiol is a big player in defeminization and masculinization of neuronal structure, synapse formation and a bunch of other stuff. How this translates (or if it does, significantly) into changes in phenotype isn't really known.

I only know about the brain, though.
posted by gaspode at 11:34 AM on January 6, 2006

Personal anecdote: My best friend continued to take her BCP for over 3 months into her pregnancy because she had no clue she was pregnant at the time. The kid came out fine and he's almost 4 now with no notable disabilities.
posted by chiababe at 12:11 PM on January 6, 2006

Again, not looking for personal anecdotes, unless your friend took BCPs for their entire pregnancy. But thanks.
posted by agregoli at 1:14 PM on January 6, 2006

delmoi, other way around: testosterone gets aromatized into estradiol (main type of estrogen).

Ah, I couldn't remember which direction it went.

Ultimately I think this would manifest itself most in a personality diffrence. The baby would be normal, well within the norm for humans, but they would be diffrent then they otherwise would have been. Only a large-scale study could suss out the differences.
posted by delmoi at 2:04 PM on January 6, 2006