It's Oh, Oh OH...So Not Happening.

The question: Is she faking it? The answer: Yeah, probably. But not with me. NEVER WITH ME.

That pretty well sums up the research done by the American Psychological Association on orgasms, real and make believe. Ninety percent of men worry if their partner has an orgasm and they worry more when their wives or girlfriends had been away for a while. "Our research gives some preliminary evidence supporting the idea that the female orgasm functions to selectively uptake a particular man’s sperm over another,” William McKibbin says. McKibbin is a psychology professor at the University of Michigan, Flint.

Men subconsciously worry that if their women have been away for a while, they may have slept with another man and gotten pregnant. They hope to beat the other man's sperm to the punch by giving her an orgasm, thus helping his sperm to get to the egg before the rival's sperm.

Some researchers tend to be skeptical of the idea that a woman's orgasm has much of an effect on her likelihood of getting pregnant. Indiana University professor Elisabeth Lloyd, PhD, mentions that only 8% of women consistently have an orgasm from penis-vagina sex alone. She says that female orgasm is just a happy accident due to the fact that men have orgasms. (Yeah, I said it. Women have orgasms because of men. HA.) However, that's just because male and female fetuses share some biology early in their development. Men's tissues just get more developed over time.

So its not totally clear what effect, if any, an orgasm has on the odds of conception. Still, supporters of the theory do have their reasons to think that it does. A study at the University of Manchester in England found less sperm in the flowback of women that had orgasms than in the flowback of women that did not. (Flowback is the stuff and comes out of the vag after sex.) Another study at the Universities of Erlangen and Gottingen in Germany found that uterine contractions during orgasm help move sperm towards an egg. They suggest that women that are better at having uterine contractions are more likely to get pregnant.



Thanks to Karen Alloy for mentioning this study on her YouTube blog.
Source:
http://www.apa.org/monitor/2011/04/orgasm.aspx