Most fertility guidance suggests keeping your legs elevated or lying on your back for 10 to 15 minutes after intercourse. There’s no need to stay in position longer than that. The goal is simple: give sperm a brief window where gravity isn’t working against them as they begin their journey toward the egg.
Why 10 to 15 Minutes Is the Sweet Spot
After ejaculation, semen starts out as a thick, gel-like substance. Proteins from the seminal vesicles form a temporary barrier that encapsulates sperm, and it takes roughly 20 to 30 minutes for semen to fully liquefy into a fluid state that frees sperm to swim on their own. Lying down during those first minutes keeps the semen pooled near the cervix while this process plays out, rather than letting it flow away from where it needs to be.
The strongest evidence comes from a clinical study on intrauterine insemination (a procedure where sperm is placed directly into the uterus). Women who stayed lying down for just 10 minutes afterward had a pregnancy rate of 29% per couple, compared to 10% among women who got up immediately. The pregnancy rate per cycle nearly tripled: 13.3% versus 4.4%. While this involved a medical procedure rather than intercourse, the underlying logic is the same. Keeping sperm close to the cervix for a short period gives them a meaningful head start.
Legs Up, Pillow Under Hips, or Just Lying Flat
You’ll find different variations of this advice: rest your legs up against a wall, tuck a pillow under your hips, or simply lie on your back. No single position has been proven superior to another. All three accomplish the same thing by using a slight downward angle toward the cervix. A pillow under your hips creates a gentle pelvic tilt that pools semen in the right direction. Legs up a wall does something similar. Even just lying flat on your back is enough.
Pick whatever feels comfortable and sustainable for 10 to 15 minutes. You don’t need to do a headstand or hold an awkward pose. Standing up or going to the bathroom too soon may pull semen away from the cervix, so the one thing worth avoiding is jumping up immediately.
You Can Still Pee Afterward
If you’re prone to urinary tract infections, you’ve probably heard that urinating after sex helps flush bacteria from the urethra. The good news is that peeing does not interfere with conception. The urethra and the vagina are separate openings. Urine exits through the urethra, while sperm travel up through the vagina and cervix. Urinating after your 10 to 15 minutes of rest won’t wash away any sperm that matter.
There’s no reason to choose between UTI prevention and trying to conceive. Just wait out the brief rest period, then use the bathroom normally.
What Actually Matters More Than Position
Lying down briefly can help, but it’s a small piece of a much larger fertility picture. The factors that have the biggest impact on your chances each cycle include timing intercourse within your fertile window (the five days before ovulation and the day of ovulation itself), sperm health, and overall reproductive health.
Sperm are surprisingly capable swimmers. Once they enter the cervical mucus, they can reach the fallopian tubes within minutes, and they survive in the reproductive tract for up to five days. The brief rest period after sex simply reduces the amount of semen that leaks out before sperm have a chance to enter the cervix. It’s a practical step, not a magic trick.
No specific sexual position has been proven to improve pregnancy odds either. Missionary, from behind, side-lying: none outperform the others in studies. What happens after sex matters slightly more than what happens during it, and even then, the effect is modest compared to getting the timing right relative to ovulation.
When Longer Rest Doesn’t Help More
You might wonder if 30 or 45 minutes would be even better. There’s no evidence that resting beyond 15 minutes provides additional benefit. By that point, semen has largely liquefied, motile sperm have already entered the cervical mucus, and gravity’s role is essentially finished. Spending a half hour with your legs in the air won’t hurt anything, but it won’t meaningfully improve your odds compared to the standard 10 to 15 minutes.
The practical takeaway is straightforward: after intercourse, lie back comfortably for about 15 minutes with a pillow under your hips if you’d like, then go about your day. It’s one of the simplest things you can do to give sperm a slight advantage, and it costs nothing but a few minutes of your time.