Fact vs. Fiction: Does Sex Induce Labor?

By the time the end of the third trimester rolls around, many moms-to-be are eager to put pregnancy behind them and meet their baby. We get it: After nine+ months of aches, pains and discomforts, it’s no wonder you’re ready to move on. As you approach your due date, you may be wondering when labor will start—and whether there’s anything you can do to induce labor naturally. So it begs the question: Does sex induce labor? Keep reading to get the lowdown from experts on whether or not you can use sex to induce labor, plus what you need to know about this method before giving it a try.

When Can You Try to Induce Labor at Home?

Before trying to have sex to induce labor—or using any at-home induction methods, for that matter—check in with your doctor or midwife to get the green light. To allow for critical fetal development, it’s important to let the pregnancy come to full term whenever possible. Experts define “term” as 37 through 40 weeks and “full term” as 39 to 40 weeks. “Babies tend to do best when born during weeks 39 and 40, with babies born before 39 weeks having a higher risk of breathing problems, developing infections and spending time in the NICU,” says Jessica Shepherd, MD, an ob-gyn at Baylor University Medical Center in Dallas, Texas, and chief medical officer at VeryWell Health. “A baby’s lungs, liver and brain continue to develop during those last weeks of pregnancy. It also reduces the likelihood of vision and hearing problems, gives the baby time to gain sufficient weight and promotes being able to suck, swallow and stay awake after birth long enough to eat.”

Once you’re 39 weeks pregnant, it’s generally safe to deliver, according to Rebekah Mustaleski, a certified professional midwife and compression director with Motif Medical. At this point, as long as you have your provider’s approval, “you can start doing natural things to get labor started,” she says. So can sex induce labor?

Does Sex Induce Labor?

The short answer is no. “Unless your body is ready to go into labor, having sex won’t prompt the onset of labor in a healthy pregnancy, even if you’re full term,” Mustaleski says. But while it won’t send you into labor, sex could potentially help things along. Here’s the deal:

Theories on having sex to induce labor

Sex in late pregnancy has long been touted as an at-home method for bringing on labor contractions—and there’s some sound logic behind it. Prostaglandins are hormone-like substances found in semen and released by a woman’s body during sex. These prostaglandins help ripen the cervix, Shepherd says, which is the softening of the cervix that has to happen in order for dilation to begin and labor to progress. In fact, doctors use synthetic prostaglandins to ripen the cervix when inducing labor.

“It’s true that semen can help start preparing your cervix to open and dilate, but it won’t put you into labor,” Mustaleski says. “It might make your cervix more responsive to your contractions once you are in labor, though, so sex at the end of pregnancy is usually a good thing!”

During orgasm (and when her nipples are stimulated), a woman’s body also releases oxytocin—the same hormone that drives labor contractions. “It’s what causes all of those wonderful feelings during climax. It’s also why some women feel crampy after they have sex, because the oxytocin is also causing the uterus to contract,” Mustaleski explains. “But unless your body is already prepared for labor, the oxytocin released during orgasm isn’t going to put you into labor. There are several other hormones required to complete the ‘labor cocktail,’ and without all of them, you’ll just have a good time with your partner.”

Research on having sex to induce labor

There isn’t enough research to support the claim that you can use sex to induce labor, says Casey Selzer, a certified nurse midwife and director of education at Oula, a maternity center in New York City.

A 2012 study looked at 1,100 pregnant women and found no direct relationship between having sex late in pregnancy and inducing labor. A smaller 2014 study looked at whether vaginal intercourse could induce labor at term and similarly found no direct relationship. More recently, a larger 2019 study, using data sets from three trials and close to 1,500 women, also found that vaginal intercourse didn’t help induce labor at term.

Still, the research on using sex to induce labor isn’t entirely black and white. A 2005 study found that breast stimulation appeared to help induce labor, but further research was needed. A small 2006 study concluded that sex at term was associated with a reduced requirement of induction at 41 weeks, and a 2015 study concluded that sex in the last week of pregnancy might be associated with the onset of labor. The key takeaway from all three? While there was some indication that sex might help bring on labor, there is no definitive cause-and-effect relationship between the two.

Having Sex in Late Pregnancy

If you’re concerned that having sex may push you into preterm labor, experts say that unless your provider has advised against sex due to a medical condition, you have nothing to worry about. “There is no evidence to support that sex during pregnancy causes preterm labor when no other medical risk factors for preterm labor are present,” Selzer says. “Because there is no evidence that sex actually induces labor, unless there is a medical complication such as placenta previa or a high risk of preterm labor, sex has been proven to be completely safe in pregnancy, regardless of the number of weeks you are.”

You may notice a tightening of your uterus after sex due to Braxton Hicks contractions, she adds, but these aren’t labor contractions and will go away after a while. If you’re experiencing regular uterine cramping after sex that doesn’t resolve or any vaginal bleeding or fluid leakage, contact your provider.

When it comes to having sex late in pregnancy, you should always listen to your body. If you’re anxious about having sex, then don’t, Mustaleski says. After all, if you’re worried about its effects on your pregnancy, you won’t be able to enjoy it. (Plus, there are plenty of other ways for you and your partner to be intimate.) “To help put your mind at ease, though, I will remind you that unless your body is already prepared to go into labor, having sex won’t make you have a baby,” Mustaleski adds. “If only it were that simple—we wouldn’t need all of the labor-inducing medications and methods we’ve developed.”

While sex isn’t guaranteed to help you meet baby sooner, as long as you have a healthy pregnancy and feel up to it, there’s no harm in trying different sex positions to induce labor. All three experts agree the main thing to focus on with sex late in pregnancy is comfort—and this will be different for each woman. Some of the best sex positions in the third trimester? “If you’re choosing penetrative sex, often the side-lying or hands-and-knees position, supported with a pillow, may be more comfortable,” Selzer says. “If your goal is to deposit sperm close to your cervix, deeper penetration would be more effective at that.” If you have questions or concerns about having sex during pregnancy or using sex to induce labor, speak with your doctor or midwife and follow their recommendations for your specific circumstances.

The biggest piece of advice Mustaleski has for women getting antsy about starting labor? Don’t stress out about it! “Remember, there is a huge mind-body connection. If you obsess about getting labor started, you’re actually less likely to get labor started!” she says. “It’s a great introduction to parenting—when you learn that kids do things when and how they want to!”

Please note: The Bump and the materials and information it contains are not intended to, and do not constitute, medical or other health advice or diagnosis and should not be used as such. You should always consult with a qualified physician or health professional about your specific circumstances.

Plus, more from The Bump:

Inducing Labor: What to Know About the Induction Process

What Is Cervidil—and How Does It Help Induce Labor?

Exercises to Help Induce Labor