There are a lot of myths out there about triggering labor: eating spicy foods, dancing, taking a shot of castor oil, and so on. The point being: 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% 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,” says Jessica Shepherd, MD, ob-gyn and director of minimally invasive gynecology at the University of Illinois College of Medicine in Chicago.
Research on the topic is ambiguous. For example, in a study published in the journal Obstetrics & Gynecology, researchers found that sex did induce labor at 41 weeks. A few years later, though, a replication of the study published in the Singapore Medical Journal found that sex was less likely to make women go into labor.
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, says 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 women with a history of early labor or of a weak cervix,” Gersh says.
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,” Shepherd says, 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.
Meanwhile, orgasms trigger a surge of oxytocin release, which is key to the production of labor contractions, Gersh says. “Studies have found that your body releases oxytocin upon orgasm, a hormone similar to Pitocin—the drug doctors use to start or speed up labor because it causes uterine contractions,” says 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 whether you’re doing it doggy style or spooning 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 doctor. 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 women 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.
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