Get It On and Get It... Out? Can Having Sex Induce Labor?

Sexual intercourse may stimulate labor in several different ways.

If you’re in your second or third trimester, you may have already noticed that you experience a hardening of your uterus after having sex. This is because the contractions you have after orgasm (or even just the increase in physical activity) may set off what are called Braxton-Hicks or “false” labor contractions.

Braxton-Hicks usually go away with rest or water or a change in position, so they’re not the real deal. But as you get closer to your due date, you may want to pay close attention, because at some point these tightenings can turn out to be true labor.

How sex may help initiate labor, at least in theory:

• Semen contains prostaglandins — lipid compounds that produce hormone-like effects. In fact, scientists say that of all the prostaglandin-containing substances produced by the body, semen contains the most concentrated form. During sexual intercourse, when ejaculate enters the vagina, these prostagladins are deposited near the cervix and can help ripen (soften) it to prepare for dilation and may even cause the uterus to contract.
• Beyond that, the uterine contractions produced by the female orgasm may also bring about labor. Again, you may notice tightenings in your lower abdomen after sex. These may just be Braxton-Hicks, but if they get enough strength and rhythm, they may end up being the real thing.
• Oxytocin is the hormone released during orgasm. It’s also called the “love hormone” because it plays a role in romantic relationships, sex, reproduction, and even bonding between caregivers and infants. What you may find interesting is that oxytocin is the natural form of Pitocin. Sound familiar? Yup — Pitocin is the synthetic hormone you may receive in a drip if you have a formal induction at a hospital.

Related: Sex drive during pregnancy: 5 things that happen

There’s a surprising amount of research on the topic of sex and labor — some dating back decades. Sex isn’t considered the most effective way to get things going — but that doesn’t mean your efforts will be in vain.

Keep in mind that if your body isn’t ready to labor, nothing you do will necessarily get you going. That’s why sex at any stage of your pregnancy is still safe.

Having sex will not cause labor to begin before your body is ready for delivery. Instead, the prostaglandins, uterine contractions, and oxytocin may simply augment the processes that are already at work (whether you realize it or not).

Yes, sex works!

In a 2006 study, researchers asked women to keep a record of sexual activity after they had reached 36 weeks of gestation. Some 200 women completed diaries. The results showed that the women who were sexually active at term did tend to deliver sooner than those who did not have sex. Not only that, but the need for labor induction was also reduced.

In a 2014 study, a group of researchers collected data from a university hospital. Over 120 women presented at the hospital with signs of labor, like bloody show or ruptured membranes, and they were asked about their sexual activity in the week prior.

The researchers discovered that the gestational age of babies born to sexually active couples was “significantly lower” than those born to couples who were not active. They concluded that sexual intercourse may very well be associated with bringing on labor.

Nope, try something else!

On the flip side, a 2007 article published in Obstetrics and Gynecology did not show a positive relationship between sexual intercourse and labor. In the study, around 200 women were split into two groups and given instructions to either have sex in the weeks before delivery or to abstain. The rate of spontaneous labor between the two groups was 55.6 percent and 52 percent, respectively. Pretty much the same.

Further, an earlier study that appeared in the same publication echoed these results. This time, the researchers examined 47 women who had sex at term (39 weeks) versus another 46 who were not sexually active. The gestational age of the babies born to the sexually active women was actually slightly older (39.9 weeks) than those who were not active (39.3 weeks). The team concluded that sex at term does not induce labor or ripen the cervix.

Related: How to start labor contractions

In other words, sex may or may not induce labor. But is sex safe during pregnancy? The short answer is yes.

First things first: Your partner’s penis won’t poke your baby’s head. It’s cushioned by amniotic fluid, your mucus plug, and muscles of the uterus.

Now that this popular myth is out of the way, sexual intercourse is fine and dandy, provided you don’t have certain complications, like placenta previa, incompetent cervix, or preterm labor, where your doctor or midwife has placed you on “pelvic rest.”

Other considerations:

• Keep it fresh. Most positions you enjoyed before pregnancy are still safe during pregnancy. If something stops feeling comfortable, try another position that feels good.
• Practice safe sex, like using condoms. Even though you’re pregnant, you should still take precautions to guard against sexually transmitted infections (STIs), which you can get from vaginal, anal, or oral sex.
• Don’t have your partner blow into your vagina during oral sex. Doing so may cause what’s called an air embolism. This means that the air bubble blocks the blood vessels, and it is dangerous for both you and your baby.
• Use caution with anal sex. Since the anus has plenty of bacteria, any vaginal penetration after anal sex may spread the bacteria into the vagina. While the mucus plug is there to protect the uterus from bacteria, you may still develop an infection that can spread to your developing baby.
• Do not have sex if your water has broken. Intercourse may introduce bacteria into the vaginal canal. When the membranes are ruptured, this means the bacteria/infection can more easily reach your baby.
• Contact your doctor or head to the emergency room if you experience anything like a gush of fluid, pain or severe cramping, or heavy bleeding after sex.

Even if sex or an orgasm doesn’t set you into full labor, you may still experience Braxton-Hicks contractions or “false” labor. These feel like a hardening of your uterus and usually do not come in any predictable pattern.

Real labor contractions are regular, last between 30 to 70 seconds, and continue to come on longer and stronger whether or not you rest or change position.

Related: Are contractions after sex normal?

Not in the mood?

It’s also totally normal to not want sex when you’re 9 months pregnant. Maybe your libido is lacking or you just can’t find a comfortable position. Maybe you’re just tired.

At the core, sex is about intimacy. You can still feel close to your partner by doing things like massage, cuddling, or kissing. Keep the line of communication open and discuss your feelings with your partner.

If you still are looking to jump-start your labor, you might try masturbation, which will still get those uterine contractions and oxytocin going. And nipple stimulation actually has some research backing it as a labor induction method — safely in low-risk pregnancies — in its own right. You may do this manually or with the use of a breast pump.

Whatever the case, be sure to check with your doctor before you try to induce labor on your own.

Related: Masturbation during pregnancy: Is it safe?

The research is split on whether or not sex in late pregnancy induces labor. This doesn’t mean you can’t try (and enjoy) this method for yourself.

Be sure to check in with your doctor to make sure you don’t have any conditions that would make sex near your due date risky. Otherwise, find a comfortable position and see what happens. If nothing else, it may be a fun way to pass the time when it feels like all you’re doing is waiting for your little one to arrive!