# Likelihood of conception **URL:** \ **Category:** Factual Questions\ **Created:** [May 28, 2006, 2:14pm UTC](https://boards.straightdope.com/t/likelihood-of-conception/358539 "2006-05-28T14:14:39Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Fiveyearlurker](https://avatars.discourse-cdn.com/v4/letter/f/da6949/32.png) [@Fiveyearlurker](https://boards.straightdope.com/u/Fiveyearlurker)\ **Post date:** [May 28, 2006, 2:14pm UTC](https://boards.straightdope.com/t/likelihood-of-conception/358539/1 "2006-05-28T14:14:39Z")
I realize that there will be a large amount of “It depends” to this question, but the wife and I are finally trying to get pregnant, so I’m just looking ballpark. So, assuming that we have sex daily in the five day period of her cycle where conception is most likely, and also assuming that we are healthy, what are the odds that in any given month that will lead to egg fertilization and implantation? ---
**Author:** ![Sattua](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sattua/32/11906_2.png) [@Sattua](https://boards.straightdope.com/u/Sattua)\ **Post date:** [May 28, 2006, 2:24pm UTC](https://boards.straightdope.com/t/likelihood-of-conception/358539/2 "2006-05-28T14:24:03Z")
I believe that, assuming everyone is healthy and motile and all that, the likelihood of conception during one of the woman’s cycles is 1/2, and the likelihood of implantation is 1/4. I tried to Google this for a citation, but all I’m coming up with are infertility websites. I heard this statistic from someone who was talking about birth control pills. And even though you know it already: it SO depends. Everyone is different. This is the weak spot in statistics–it doesn’t have anything to do with the individual. ---
**Author:** ![WhyNot](https://avatars.discourse-cdn.com/v4/letter/w/c77e96/32.png) [@WhyNot](https://boards.straightdope.com/u/WhyNot)\ **Post date:** [May 28, 2006, 2:27pm UTC](https://boards.straightdope.com/t/likelihood-of-conception/358539/3 "2006-05-28T14:27:31Z")
Well, it’s hard to say. It’s believed that a whole lot of potential pregnancies never happen because conception doesn’t occur, or because the blastocyst doesn’t implant, or because it does but stops developing and is expelled during a “heavy period” without the woman ever knowing she was pregnant. So they’re not reported and tracked. We know from IVF that up to 75% of embryos made from IVF patients have abnormal chromososmes. Of the normal ones, implantation rates are about 25-30%. [cite.](http://www.genomenewsnetwork.org/articles/12_00/fertile_genome.shtml) But these are from IVF patients, remember - generally older and with fertility challenges. The other number we can look at is the pregnancy rate of couples using no birth control. 85% of them will be pregnant within a year. [cite.](http://www.fda.gov/Fdac/features/1997/conceptbl.html) If your sperm count and mobility is normal, and if your wife has healthy eggs and a good supply of quality fertile cervical fluid and you time the intercourse for a day or two before ovulation, your chances are pretty damn good. But I don’t have a number for you, sorry. Please do pick up a copy of [Taking Charge of Your Fertility](http://www.amazon.com/gp/product/0060937645/qid=1119722711/sr=8-1/ref=pd_csp_1/102-9945800-7350530?n=507846&s=books&v=glance) for more information on pregnancy achievement. It will give you a whole new appreciation of your wife’s amazing body. ---
**Author:** ![Maastricht](https://avatars.discourse-cdn.com/v4/letter/m/a88e57/32.png) [@Maastricht](https://boards.straightdope.com/u/Maastricht)\ **Post date:** [May 28, 2006, 2:32pm UTC](https://boards.straightdope.com/t/likelihood-of-conception/358539/4 "2006-05-28T14:32:05Z")
> [@WhyNot](#): > > Please do pick up a copy of [Taking Charge of Your Fertility](http://www.amazon.com/gp/product/0060937645/qid=1119722711/sr=8-1/ref=pd_csp_1/102-9945800-7350530?n=507846&s=books&v=glance) for more information on pregnancy achievement. Seconded. Very readable book, and armed with the information in it you and your wife will feel a lot more in charge and a lot less like you’re playing a form of roulette you’ve been vaguely told the rules of. ---
**Author:** ![don\_t\_ask](https://avatars.discourse-cdn.com/v4/letter/d/e68b1a/32.png) [@don\_t\_ask](https://boards.straightdope.com/u/don_t_ask)\ **Post date:** [May 28, 2006, 2:35pm UTC](https://boards.straightdope.com/t/likelihood-of-conception/358539/5 "2006-05-28T14:35:05Z")
The numbers I recall are the same as those quoted by **Sattua** - about a 1 in four chance per cycle and about 75 - 80% per year. So you are long odds on to be pregnant within a year, but not so certain that you should worry if you aren’t. ---
**Author:** ![Fiveyearlurker](https://avatars.discourse-cdn.com/v4/letter/f/da6949/32.png) [@Fiveyearlurker](https://boards.straightdope.com/u/Fiveyearlurker)\ **Post date:** [May 28, 2006, 2:35pm UTC](https://boards.straightdope.com/t/likelihood-of-conception/358539/6 "2006-05-28T14:35:49Z")
Thanks for the links, those are about the ballpark figures that I wanted to know, particularly the 85%. We sort of decided to give it four months (this is the first, and we will find out success in the next few days) of trying before we start being too concerned that there is any sort of worry. We’re both in our early 30s, so it’s not the slam dunk it would have been five years ago, but her family has a history of, well, fertility. ---
**Author:** ![WhyNot](https://avatars.discourse-cdn.com/v4/letter/w/c77e96/32.png) [@WhyNot](https://boards.straightdope.com/u/WhyNot)\ **Post date:** [May 28, 2006, 2:40pm UTC](https://boards.straightdope.com/t/likelihood-of-conception/358539/7 "2006-05-28T14:40:31Z")
Most ethical IVF docs won’t schedule an appointment with a 30something unless they’ve been “trying” for a year. Here’s a potentially useful quote/link I found: > [@](#): > > As a general rule, 55 percent of couples who try to get pregnant naturally will conceive within three months, 72 percent within six months, and 85 percent by the end of one year. It depends on age, but typically if a couple has been trying for a year without success, it is appropriate to seek treatment with an infertility specialist. Usually, if a woman is younger than 35, one year of unprotected intercourse should be adequate to achieve pregnancy. The closer a women gets to 40, the sooner she should seek help, sometimes even after only six months of trying. From [Ask An Expert](http://healthjournal.upmc.com/0405/AEinfertility.htm) Keep us updated, and remember the Post Pics rule for babies and kittens! ---
**Author:** ![David\_Simmons](https://avatars.discourse-cdn.com/v4/letter/d/9de053/32.png) [@David\_Simmons](https://boards.straightdope.com/u/David_Simmons)\ **Post date:** [May 28, 2006, 3:10pm UTC](https://boards.straightdope.com/t/likelihood-of-conception/358539/8 "2006-05-28T15:10:32Z")
[hijack]A woman was on a TV audience participation show and was asked how many children she had. “Sixteen” “How many boys and how many girls?” “All boys.” “I see, a boy every time, eh?” “Oh no, hundreds of times there was nothing.”