How many times should you have intercourse to induce labor

Is having sex to induce labor in your third trimester really possible? We spoke with an expert to find out.

Photo: Illustration by Emma Darvick

You've probably stumbled across the old wives' tale saying that sex can induce labor. The reasoning behind this claim makes sense (orgasms release hormones and spur contractions) but you shouldn't be too hasty to hop under the sheets. It turns out that this natural way to induce labor may not necessarily be true.

"There are no consistent scientific facts to support the notion" that sex can induce labor, says Jimmy Belotte, an Ob-Gyn in the Department of Obstetrics & Gynecology and Women's Health at Montefiore Health System, and an associate professor in the Department of Obstetrics & Gynecology and Women's Health and the Albert Einstein College of Medicine. Your body needs to be completely ready to give birth, so having sex at 37 weeks or 39 weeks probably won't cause any labor symptoms.

On the other hand, some experts believe that having intercourse when you're overdue (40 weeks and beyond) can put you on the fast track to labor. "Theoretically, the stimulation of the cervix and orgasm during sexual intercourse have the potential to trigger labor," explains Dr. Belotte. That's because orgasms mimic the motion of uterine contractions, which may prompt the real thing.

Prostaglandins – a hormone-like substance found in semen – may also spur labor when it's introduced to a woman's birth canal. "Semen contains chemicals capable of softening the cervix and initiating contractions," explains Dr. Belotte. In fact, prostaglandins are also used in medical inductions.

Along those lines, sexual intercourse releases oxytocin, which is also known to cause contractions. (Pitocin, a synthetic form of oxytocin, is commonly used to induce labor at the hospital). Nipple stimulation releases oxytocin as well, so feel free to add it into your foreplay as long as you run it by your doctor first. Overstimulation of the nipples can bring on too strong or too frequent contractions.

Is Sex to Induce Labor Safe?

If you're antsy to induce labor, there's nothing stopping you from having pregnancy sex – as long as your ginormous belly and swollen body don't make things too comfortable. As an added bonus, pregnancy sex comes a host of benefits, including lower blood pressure, better sleep, and increased intimacy with your partner.

Keep in mind, however, that having sex while expecting isn't safe for everyone. Women with certain pregnancy complications – such as placenta previa and risk of preterm labor – should avoid intercourse altogether. You also shouldn't have sex after your water breaks or else an infection could occur. Always consult a doctor if you're unsure.

Also, while there's no best sex position to induce labor naturally, you should also follow safe pregnancy sex practices. For example, avoid having the woman lay on her back, which may harm the fetus. "It is recommended that sexual positions like the woman on top, or the couple laying down sideways with the pregnant woman in front, are preferred to minimize discomfort and increase blood flow," explains Dr. Belotte.

There are a lot of myths out there about ways to trigger labor including eating spicy foods, dancing, taking a shot of castor oil, and others. The point is, that by the time a woman is 40 weeks pregnant, she's ready to do pretty much anything to get that baby out of her body.

In fact, nearly 30 percent of 2,400 mothers surveyed by maternity care organization Childbirth Connection reported trying to induce labor on their own.

But one of the most persistent myths is whether having sex can actually induce labor. After all, it's what got you into this situation...can it help you out of it?

Not officially. "There have been many studies on sex-inducing labor and most studies have not been able to find that the role of sexual intercourse can be used as a method of induction of labor," said Jessica Shepherd, MD, OB-GYN, and director of minimally invasive gynecology at the University of Illinois College of Medicine in Chicago.

According to a 2022 study published in American Family Physician, although exercise and nipple stimulation can increase the likelihood of spontaneous labor, sexual intercourse may not be effective.

And a 2019 meta-analysis published in The Journal of Sexual Medicine looked at clinical trials involving 1,483 women. The authors write that sexual intercourse during pregnancy is commonly believed to trigger the onset of contractions and, therefore, labor. However, in low-risk pregnancies, there is neither association with preterm birth, premature rupture of membranes, or low birth weight, nor with spontaneous onset of labor at term.

That said, it's not a totally bogus idea. There are a couple of theories as to why sex could prime the body for labor. For starters, there's the fact that sex causes mechanical irritation of the cervix, said Felice Gersh, MD, OB-GYN, and director of the Integrative Medical Group of Irvine in California.

"During sex, the physical rubbing and touching of the cervix by the penis can potentially affect the cervical mucous and stimulate the release of labor-stimulating substances in people with a history of early labor or of a weak cervix," said Gersh.

Sex also involves two hormones that are crucial to labor, prostaglandins, and oxytocin. "Human semen is the biological source that is presumed to contain the highest prostaglandin concentration," said Shepherd, and unprotected sex is definitely going to introduce that to the cervix. Prostaglandins soften and open the cervix, which could lead to the onset of contractions, according to the American Family Physician study.

"Meanwhile, orgasms trigger a surge of oxytocin release, which is key to the production of labor contractions," said Gersh.

"Studies have found that your body releases oxytocin upon orgasm, a hormone similar to Pitocin—the drug healthcare providers use to start or speed up labor because it causes uterine contractions," said Nita Landry, MD, OB-GYN, and co-host of talk show The Doctors. If you have post-climax contractions, you could theoretically trick your body into thinking it's time for labor contractions, but that hasn't been proven.

A quick Google search will show that there's a lot of debate around the best sex positions to induce labor—but that's a moot point. Labor is brought on by hormonal changes, as explained above, so your sexual position doesn't really matter. What matters (in theory) is that you orgasm.

All of this is hypothetical, so don't freak out about having sex before your due date. An orgasm isn't going to spontaneously send you into labor too early. If you have concerns or have had any issues with your pregnancy, talk to your healthcare provider. Unless they tell you otherwise, though, sex is totally safe throughout the entirety of your pregnancy (except after your water has broken; that can lead to infections).

For people with normal, complication-free pregnancies, sex is only likely to trigger labor if they're full-term or past-term. So if you are at that point and you just can't take another day, go ahead and get it on.