woman holding pregnant stomach, how long does it take sperm to induce labor
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How Long Does It Take For Sperm To Induce Labor?

Trying to make your cervix open faster? Read on.

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As the end of the third trimester nears, many pregnant women start to feel desperate to go into labor. The aches, pains, and insomnia that come along with the end of a full-term pregnancy are exhausting, and you probably feel more than ready to meet the little one that’s been growing inside of you. It’s not uncommon to seek out little tips and tricks that just might speed things along. One thing that’s rumored to help naturally induce labor is having sex — a lot of people say that sperm can soften the cervix and help get things going. Assuming that’s true, you’re probably wondering how long it takes for sperm to soften the cervix, and what you can expect.

The softening of the cervix is also known as “cervical ripening.” During most of your pregnancy, the cervix will be stiff and closed to keep your baby safely enclosed in your uterus. But once you start to go into labor, the cervix will begin to soften and widen, giving your little one the space they need to get through the birth canal. Softening of the cervix is necessary to have a vaginal birth, and when it begins to happen, it’s a sign that delivery is near.

When you feel more than ready to have your baby, you might try having sex in order to speed things along. We spoke to experts about whether or not sperm can induce labor, and how long it takes for sperm to soften the cervix.

Does sperm soften the cervix?

This one isn’t just an old wive’s tale — yes, sperm can actually soften the cervix. “Human sperm has a great amount of prostaglandin,” Dr. Daisy Ayim, board-certified OB-GYN located in Houston, Texas, explains to Romper. “It can help ripen the cervix, sort of prime it. Prostaglandin is one of the agents we use for cervical induction or to induce labor. So, indirectly, human sperm — because it has prostaglandin — can help the cervix ripen and prime it for labor to start.”

That said, you shouldn’t start having sex to induce labor unless your doctor says it’s okay. “We generally don’t recommend intercourse to soften the cervix because there may be contraindications in pregnancy where intercourse is not recommended,” Ayim says. “If a woman has the ‘all clear’ from her doctor and the labor seems to be delayed... sometimes sex could be good to get you started.” She recommends talking to your doctor and making sure it’s safe for you and the baby before trying this out.

How long does it take for sperm to soften the cervix?

You might be anxious to know how quickly sperm will work to get labor started, but the truth is, there’s really no exact time frame. “Some softening will occur relatively fast, but how close it gets you to active labor depends on your cervical exam prior to intercourse,” Dr. Monte Swarup, M.D., FACOG, board-certified OB-GYN and founder of HPD Rx, explains to Romper.

There’s no exact rule about how long it will take for sperm to soften the cervix, agrees Ayim. She notes that when synthetic prostaglandin is used for cervical ripening, they usually say there’s a 12-hour window. “Sometimes patients respond to it before that window is over,” she says. “For human sperm, there’s not really a specific time frame.” In short? There’s no way to tell for sure how long it might take.

How to naturally induce labor

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It’s normal to want your pregnancy to be over with because there’s so much to look forward to once your little one has entered the world. And let’s be honest — being nine months pregnant is far from comfortable. However, you have to be careful about pushing things along. In general, it’s best for things to move along at their own pace and happen naturally. You should never try inducing labor on your own, notes Ayim, unless your doctor has said it’s OK and you’re more than 39 weeks pregnant.

Aside from having sex, she says that working out — as long as your doctor as cleared you to do so — is one way to potentially get things going. She also often advises patients to walk around more than usual. Research shows that walking is one of the most common ways of trying to inducing labor, although there are currently no studies to back it up.

“Nipple stimulation will also cause contractions, but I do not recommend it as it is an uncontrolled and unmonitored situation,” Swarup tells Romper. In fact, he doesn’t really recommend pregnant women do anything to try and induce labor unless they’ve been explicitly advised to do so. “When we do cervical ripening or induction, it is in a hospital setting under protocols for safety of mom and baby,” he says. It’s best to let nature run its course, or leave it to the professionals.

Does sex induce labor?

That being said, you should know that having sex at the end of your pregnancy may very well help induce labor, whether semen is involved or not. “Sex without ejaculation or orgasm releases chemicals that help with cervical ripening and could induce active labor depending on a starting cervical exam and the body’s response,” Swarup says. “Generally, sex is safe in pregnancy unless contraindicated by your provider.”

In short, sperm may indeed soften the cervix and help start the process of labor. However, you still need to be careful. Don’t try having sex to induce labor unless you are after 39 weeks and have the OK from your doctor. And don’t expect things to happen on a specific timeline. There is no guarantee that sperm will make you have your baby right away.


Dr. Monte Swarup, M.D., FACOG, board-certified OB-GYN and founder of HPD Rx

Dr. Daisy A. Ayim, M.D., FAACS, board-certified OB-GYN located in Houston, Texas

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