Good news and bad for women who take the pill: new research finds that those who meet their partners while taking oral contraceptives report less sexual satisfaction in their relationships — but they’re also less likely to split up.

A study of 2,519 mothers, mainly from the U.S. and Czech Republic, found that those who met their first child’s father while on the pill were less sexually satisfied with their men, less attracted to them and experienced greater sexual dissatisfaction over time, compared with women who weren’t taking birth control pills.

But they also reported greater satisfaction with other aspects of their relationships, including the financial support provided by their mates, and were about 10% more likely to stay together. (If they did break up, the split was around 10% more likely to be initiated by the woman than the man.)

So, how could the pill possibly affect mate choice? It comes down to chemistry.

The researchers had previously discovered that women’s menstrual cycles affect the types of men to which they are most attracted. Part of having “chemistry” with someone is liking his smell, which is determined in part by an immune system molecule called MHC.

People tend to be attracted to partners with MHC types that are dissimilar from their own, probably because this would give their offspring a greater chance of survival by creating a diversified immune system. The pill, however, puts the body into a hormonal state similar to pregnancy — and pregnant women tend to prefer MHC scents that are similar to their own, probably because this would make them feel safe and comfortable around supportive relatives.

That means that if you’re taking the pill, you may be more likely to find attractive men whose MHC is similar to your own — but during your regular cycle, these men might seem less your “type.”

Indeed, during their most fertile phase, women tend to be drawn to more dominant, masculine men who are more likely to be unfaithful. In contrast, during the second part of their cycle, when they could already be pregnant, they are more attracted to calmer, more nurturing types.

So, basically, meeting while on the pill might make you choose a “dad” who may not be the most exciting guy, but who will stick around and support the kids. Conversely, meeting while not taking hormonal contraceptives might make the bad-boy “cad” seem irresistible.

Of course, there are many, many variables involved in choosing a partner and the influence of taking the pill is not huge. It’s possible that other underlying factors actually account for the differences between pill users and nonusers, perhaps related to their decisions about contraception and attitudes toward sex. The researchers tried to control for these factors, however, and still found that the effect persisted in two different countries.

Lead author Craig Roberts of the University of Stirling in the U.K. told the BBC: “Choosing a non-hormonal barrier method of contraception for a few months before getting married might be one way for a woman to check or reassure herself that she’s still attracted to her partner.”

My guess, however, is that if you are that concerned about your relationship, you might have other issues to iron out before booking the caterer.

You know what leads to less sexual satisfaction for everyone involved?  Having kids!  Seems like a fair trade to me.

TheTaoOfSteve writes:

Do you do it or do you pull out?

8% yearly failure rate with couples and the fact that SHE is responsible for taking them has kept me skeptical..

So I guess I’ll take this opportunity to share some of TC’s rules for safe sex.

First of all, every guy out there knows how much condoms suck.  They’re uncomfortable, they’re inconvenient, and they just don’t feel all that great.  So the temptation to doing sans-condom is always there.  The answer to this is, of course, doing it with a girl who’s on birth control!  After all, the chances of her getting preggers is about as good as when you wear a condom, right?

Well, before you dive in (literally), there are some things you need to consider…

First of all, you’re going to want to know if you can trust this girl.  Is she reliable?  Does she actually take her pills like she’s supposed to?  Is she disease free?  If the girl is flaky, forgetful, or a slut, then those are definite warning signs you do not want to be barebacking.  Condoms may suck, but they are very good at two things – preventing pregnancy and preventing disease.  So before you toss the jimmy hats away, think about the girl you’re gonna be having sex with.

Second, try and find out her views on being pregnant before you do anything with her.  Some girls will be paranoid about getting pregnant, some might not be worried about it.  But when/if it happens, you have to know how she’ll react.  Is she strongly religious or pro-life?  If that’s the case, she may not agree to an abortion, and then you’re stuck with a kid if an accident happens.  Always find out what the girl is open to when it comes to an unwanted pregnancy before you have sex without a condom.  If she’s fine with abortions, then its okay to take the chance, but if she’s not, then don’t risk it.

Don’t bareback women you don’t know that well.  Personally, I would never bareback a girl I’ve just met, even if she said she was on the pill, barren, totally clean, or whatever.  There’s just no way I’m taking that chance.  Save off for a girl you’re in a relationship with if you can, or at least a girl you know really well.  (As in, you’ve already had sex with her a few times.)

Have some emergency precautions available as well.  Go to your local CVS or any other pharmacy, and spend $50 on a morning after pill.  This is your “saving grace” purchase.  It’s always a good idea to have this handy in case your condom breaks or comes off, but if you’re really worried, just have the girl take it after you’re done with sex (and for the love of God, actually WATCH HER take it!).  Get the kind that’s just one pill, not the kind that requires two.  This isn’t 100% effective, but it will offer some added protection if you’re worried maybe the girl hasn’t been that diligent about taking her birth control.

And if you REALLY want to be sure, take your girl in for a Depo-Provera shot.  It’s a simple injection her doctor can give her, and it can prevent pregnancy for up to three months.  This is one of the most effective birth control methods available, and it works even better if the girl gets the shot every 12 weeks, because the hormone will build up in their system.   If you REALLY wanna bang a girl without a condom and blow your load inside her, this is the way to go.  However, it does require a prescription from her doctor, so it will require time, money, and effort on her part to get it.  If she can’t afford to see a doctor or whatever, you may want to pay for this yourself.

So there you go!  Just remember that you always take a risk when you don’t jimmy up.  And it’s not just an issue of pregnancy, it’s also an issue of disease.  So be sure you trust the girl you’re with, take all the preparations you can to stay safe, and have a back-up plan just in case something goes wrong.