If you spend any time at all looking for fertility advice on the Internet, you’ve probably heard that you’re supposed to have sex every other day for the best chances to conceive. For many couples, that seems reasonable enough, and they don’t give it another thought.
But if you’re the inquisitive type, like we are, you might ask yourself: if every other day is good, wouldn’t every day be even better? Or maybe sex every other day seems like too much. Could you get away with having sex a little less? How did we land on the consensus for sex every other day, anyway? Is it one of those Internet rumors that gets repeated so much people think it’s true, or is it backed up by solid research?
It turns out that the recommendation to have sex every other day is pretty sound, but it’s a surprisingly complex path to get there. A number of factors influence the recommendation, some of them almost contradicting one another. We’ll spell it all out for you below, and reveal why some couples might be better off doing it every day. Read on, then decide for yourself.
A sperm count of at least 20 million parts per milliliter is necessary for conception to occur, and studies show that chances of conception are highest when it’s at least 40-50 million/mL. There’s a wide range for what’s considered “normal” when it comes to sperm count—anywhere from 35 to 120 million/mL.
If your guy is on the low end of that spectrum, you want to ensure that when you have sex, he has a high enough sperm concentration for conception to be possible. The best way to do that is to give him a day off between ejaculations. Of course, it’s possible that your partner has such a high sperm count that he never falls below 40 million/mL. If that’s the case, you can have sex as often as you’d like without any conception probability repercussions. But there’s no way of knowing for sure without doing a semen analysis.*
Ejaculating every two to three days keeps sperm healthy. If your partner goes more than two or three days without ejaculating, his sperm count will rise, but so will the proportion of dead, immotile, or morphologically abnormal sperm—hurting your chances for conception.
Sex During Fertile Window
Having sex every day during your fertile window (usually the five days leading up to the day of ovulation, including the OV day itself) gives you a 25 percent chance at conceiving. Doing it every other day gives you slightly lower chances, 22 percent. When couples have sex just once per week, conception probability drops dramatically—to just 10 percent.** If you have a hard time tracking your fertile window or just don’t feel like it, just have sex roughly every other day all month long. With this schedule, you’re guaranteed to have sex at some point during your peak fertile time.***
Sex During Non-Fertile Window
You might think that what you do in your non-fertile window doesn’t have much of an impact on your chances of conception. In fact, it does! A couple of recent studies have suggested, somewhat radically, that sex changes a woman’s immune system in ways that improve her chances of conceiving.
Burnout One of the biggest problems that couples who are trying to get pregnant struggle with is a feeling of burnout when it comes to sex. When we asked Ava’s beta testers how they felt about having sex for conception, they used words like “robotic,” “tedious,” “stressful,” and “emotionally draining.” For most couples, the slight increase in conception probability with daily sex versus every-other-day probably isn’t worth it. Then again, if you’re like our beta tester who told us “I’m always in the mood when I know I’m ovulating!” then hey, do it every day! (As long as your partner has a decent sperm count.)
*Interesting fact: sperm concentration for a 35-year-old man went from an average of 73.6 million/mL in 1989 to 49.9 million/mL in 2005!
**By the way, these figures reflect pregnancies that ended in live births. When miscarriages are included, the conception rates are moderately higher for both daily and every other day sex.
***In this scenario, your chances for conception *might* be slightly higher if you had sex every day during your fertile window. But without knowing exactly when that is, you’d have to have sex every single day for months on end just to make sure you were always hitting it. (Your fertile window, that is. You’d already always be hitting it.) Anyway, the modest increase in conception probability you’d gain probably isn’t work the decrease in sexual satisfaction most couples feel when they attempt to have sex that much.