Thank you for that post; I always appreciate it when someone provides links to actual studies rather than Wikipedia or media summaries. I’ll read those when I have the time.
The way failure rates are generally communicated is “For every 100 women using this method for one year, ___ will become pregnant,” not “An individual woman’s chances of becoming pregnant in one year is ___ with this method of contraception.”
Does that change your numbers? I honestly don’t remember jack from my statistics course, except that a 50% chance of becoming pregnant in 8 years on The Pill seems absurdly high and out of line with reality. Certainly 50 out of 100 women who use the pill for 8 years don’t become pregnant.
Or is this a case of lies, damn lies and statistics?
And yet you never responded to the link to the actual study that I offered earlier, in response to your distorted media summary of the study.
Edit: Direct study link
The statistics are right, but we are talking about people not dice. We aren’t talking about a 50% chance of having a baby. We are talking about 50% chance of needing an abortion. Not exactly something you are going to post on Facebook. As I alluded to earlier, but most failures are just forgetting to take your pill, which is another good reason to not spread it around that you got pregnant.
Over 8 years that is over 300 days you can get pregnant and that is over 300 times you can forget to take your pill. Then you add in people the go on a trip and forget to bring their pills or they run out and cant get a new prescription until next week. All I know, if women were as forgetful as I am, the rate would be a lot higher than 8%.
No, we’re not–I’m almost certain you’re misinterpreting the statistics. Those women who don’t take the pill perfectly have a way of weeding themselves out of the pool of women taking the pill. It’s simply not the case that over eight years, half the women on the pill get pregnant. Those pregnancies aren’t evenly distributed, a necessary factor for your analysis to be correct.
By way of analogy, If I say that in any given year, 8% of the population will end up in prison, it does not follow that in 8 years, half the population will be in prison.
Huh. Yes, you are correct. Never thought of it that way, to be honest. And I did find one sourcethat seems to verify this:
Guess that’s a pretty good argument for using more than one method.
But here’s where I’m still confused: A woman isn’t going to be fertile every day she has sex, especially on the Pill, even if she’s taking it incorrectly. She’s also not likely to have sex every time she’s accidentally fertile.
If I take my Pill perfectly all but three days in one cycle, I’m supposed to use a back up method. I may very well ovulate that month, but when is going to be unpredictable. Still, I’d have to have sex without a backup method 24 to 48 hours before that unexpected ovulation to get pregnant.
Over 8 years, a woman on *no *birth control is only fertile about 312 days (3 days a cycle, 13 cycles a year on average). How is it that Typical Use of the Pill only removes 12 of those days? That seems more like Moronic Bulimic on Antibiotics use of the Pill!
You’re forgetting that a sperm live up to three days so even if you are, strictly-speaking, fertile 3 days (maybe a couple more), the total of “dangerous” days is closer to 6 per cycle.
In fact, NFP users usually abstain for about 7-9 days.
You are apparently have some issues with math. If you look at the numbers it works out to 8% failure rate per year. That works out to 640 pregnancies per 1000 women. The chances are that most of those pregnancies happened to a minority of women and most women didn’t get pregnant at all. That still doesn’t change the probability.
The prison analogy is actually pretty close, since most people going to prison are recidivists.
Math. Not even once.
I said over300. I was rounding. 312 is actually the correct number, but I doubt many women have that perfect a period. I suspect the women who notice they forgot to take their pill and take alternative measures aren’t part of the 8%.
**Everyone in the USA has access to birth control
**
Everyone in the world has access to birth control. It’s called not screwing.
When I read up on the 3 day per cycle thing it was how the egg usually stays on the wall of the uterus and had nothing to do with sperm. If there isn’t a viable egg in the uterus, then the sperm is irrelevant.
Are you confusing me with some other poster? I haven’t commented on any of your posts.
Yeah, the way I read it (in Toni Weschler’s book, natch) is that the extra days are mostly “to be safe” bumpers. They’re rigidly defined areas of doubt and uncertainty. Because, yes, sperm live a while is good fertile mucus, you’re likeliest to get pregnant from sex the two days before you ovulate and the day of ovulation. Conceiving from sex after you’ve ovulated is actually pretty rare, as it takes the sperm some days to swim up to the fallopian tubes, and 24 hours after exiting the ovary, the egg isn’t “ripe” anymore.
So FAM predicts the day of ovulation based on your previous cycles, but it doesn’t recognize it (through a rise in basal temp), until you’ve actually ovulated. By that day, you could have gotten pregnant from sex since two days ago. To be safe, if you really don’t want to be pregnant, instead of 2, you give it 3-4 days before your predicted ovulation and call it “fertile” and abstain or use contraception - just in case you’re a day or two early with your ovulation this month. And sometimes the moment of ovulation signs are subtle, so best to extend it a day or two past the presumed ovulation, just in case you got it wrong by 24 hours this month.
It’s not that you’re actually fertile for 6-7 days a month, it’s that, using previous months’ records, you can only narrow your fertile period down to 6-7 days, 3 of which will be fertile.
That’s a particularly worthless comment.
Well exactly. The issues I have are not with math, but with your math. Your claim that you have about a 50/50 chance of being pregnant after 8 years moves the focus from pregnancies to individuals.
The chances are probably something more like this:
-After 1 year, you have an 8% chance of getting pregnant.
-After that year, you’re either off the pill, or you’re one of the bad pill users (whose chance of pregnancy in the first year was significantly higher), or you’re one of the good users. The bad users are starting to get winnowed out, replaced by other bad users; the good users remain in the group.
-In the second year, the bad users continue to have a high chance of self-selecting out; the good users probably have only, say, a 2% chance of pregnancy. Overall the number of pregnancies among women who have been using the pill for more than a year probably are less than 8%. And when you get to women who have been successfully on the pill for 8 years, there’s probably a very small annual chance of pregnancy.
Your first statement that I quoted above was an abuse of stats, precisely because it doesn’t recognize the self-selecting nature of women who continue to remain on the pill.
Joke. Public service ads about amphetamine? “Meth. Not even once.”
Where are you pulling the assumption that women will stop using the pill if they get pregnant? Do you have any documentation for that? Even if they don’t get an abortion, then they will resume taking birth control after birth. This has nothing to do with the statistic that 8% of women using the pill will get pregnant each year. You never explicitly state what the women who stop using birth control pills are doing.
I just googled it, so now I know what you are talking about, but I don’t think I’ve ever seen the ad. Substance abuse PSAs in my demographic tend to run more toward alcohol.
They’re having a baby is what many of them are doing, and so they’re stopping the pill for a year or longer. Others, seeing that the pill isn’t working for them, are switching to other forms of birth control.
I don’t have documentation for these ideas, of course, any more than you have documentation for the idea that bad pill users continue using it in exactly the same numbers as good pill users. That latter assumption is necessary for your extrapolation; I’m suggesting it’s a poor assumption.