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If you’ve hit (or passed) your due date, you may be looking for natural ways to nudge your baby along already. But can sex induce labor in full-term women? And are there risks for having sex in the last few weeks of pregnancy?

While studies on the topic are still limited, sexy time could be your ticket to labor and delivery. Here’s what you need to know about whether sex can induce labor.

Can Having Sex Induce Labor?

Sex might seem the obvious solution to speeding along labor: Contractions of the uterus are part and parcel of having an orgasm, and they can be quite powerful and last up to half an hour. But it’s not just those post-climax contractions that are thought to potentially help induce labor if your body is ready.

Sperm contains prostaglandins, or fatty acids that act like hormones, which are also produced by your uterus to thin and dilate the cervix and jump-start contractions in preparation for delivery. In fact, medications used by doctors to induce labor (like misoprostol) contain a synthetic version of prostaglandins that have been shown to help speed along labor.

What’s more, nipple and genital stimulation as well as orgasm have been touted as a natural way to increase levels of oxytocin, a hormone produced by your body to trigger labor contractions when you’re ready to deliver. Oxytocin is also commonly used by doctors in a synthetic form to induce labor.

Does Sex Always Induce Labor?

Although there’s reason to think that late-term sex could potentially induce labor, there just hasn’t been enough research to prove that it really works. One small study found that sex did, in fact, induce labor in low-risk women at 41 weeks — but when the study was repeated a few years later, full-term women who got it on were actually less likely to go into labor. In fact, most of the studies that have been done have either been inconclusive or shown that sex does not induce labor.

When Can Sex Bring on Labor?

Research shows that for women with normal, complication-free pregnancies, sex and orgasm don’t trigger labor unless conditions for labor are ripe — in other words, if you’re full-term or past-term.

Is It Risky to Have Sex in the Last Weeks of Pregnancy?

Worried that sex might induce labor a bit too soon — from week 32 up to 37, 38 or 39 weeks? The contractions after orgasm aren’t a sign of labor unless your body is ready for it. If there’s a reason you shouldn’t have sex during pregnancy (because you’re at high risk for preterm labor or have a placenta problem, for example), your practitioner has likely already brought it up with you (and usually well before the home stretch). So if you still have the urge to get it on and you have the green light from your ob-gyn or midwife, go for it!

Can Some Sex Positions Induce Labor More Than Others?

There’s just no good research showing that any sex positions are more likely to induce labor than others. That said, a key ingredient to sex potentially inducing labor is that both of you orgasm — so choose whatever position (woman-on-top is a favorite pick) or sex toy that does it for you.

Remember that there are, of course, some sex positions you simply can’t attempt in the last few weeks of pregnancy —  notably your partner on top, since you should avoid spending too much time on your back to avoid cutting off blood supply to your lower body (plus it would practically take an acrobatic feat to comfortably navigate that baby bump). Rear-entry and side-lying are two other good options at the very end of pregnancy.

Bottom line: Most practitioners allow patients with normal pregnancies to have sex right up until delivery day without fear that they’ll go into labor before it’s really time. But check with yours to see what’s safe in your situation.

From the What to Expect editorial team and Heidi Murkoff, author of What to Expect When You’re Expecting. Health information on this site is based on peer-reviewed medical journals and highly respected health organizations and institutions including ACOG (American College of Obstetricians and Gynecologists), CDC (Centers for Disease Control and Prevention) and AAP (American Academy of Pediatrics), as well as the What to Expect books by Heidi Murkoff.