Why sperm induces labor

There is a proliferation of DIY methods to induce labour that can be found online, and one of the most common recommendations is to have sex. But does sex initiate labour? There are biologically plausible reasons why having sex at term may help to speed the arrival of a baby. First, semen is a natural source of prostaglandins, which are used in synthetic form to encourage cervical ripening in preparation for labour.

Second, sex plus or minus orgasm has been found to increase uterine activity, and nipple stimulation is also thought to stimulate the uterus to induce labour.

But despite the biological plausibility and popularity in the community, there has been very little scientific evidence so far to support sex as a method of inducing labour. One study found that sexual intercourse at term was associated with earlier onset of labour. However, when the researchers repeated this study , they found the reverse: women who reported having sex at term were actually less likely to go into spontaneous labour than women who abstained.

Clare Herbert Community midwife. Many parents are adamant that having sex brought on labour for them. There are several ideas behind the theory, including the role of orgasms in stimulating the womb uterus , the release of oxytocin inducing labour contractions and sperm helping to soften the opening to the womb cervix. Can having an orgasm induce labour? Having an orgasm is one of three theories behind why having sex could help you go into labour. The theories are:. J Sex Med. Epub Sep PMID: Effect of vaginal intercourse on spontaneous labor at term: a randomized controlled trial.

Archives of Gynecology and Obstetrics 6 : Women's use of nonprescribed methods to induce labor: a brief report. Birth 38 2 : The association of sexual intercourse during pregnancy with labor onset. Iranian Red Crescent medical journal, 17 1 , e The orgasmic history of oxytocin: love, lust, and labor. Methods of induction of labour: a systematic review. BMC Pregnancy Childbirth Inducing labour. National Institute for Health and Care Excellence.

The other half were told that sex was safe during pregnancy, but that its effects on labor were unknown. The researchers then tracked the women to determine how long their pregnancies lasted and whether they required any medical intervention to start labor. They found that about 85 percent of the women who were encouraged to have sex did follow the doctor's advice, while 80 percent of women in the other group also had sex.

Women in the group advised to have sex also had it more frequently for the remaining duration of their pregnancies - three times versus two. But the rates of induced labor were similar in both groups: 22 percent of those advised to have sex and Jonathan Schaffir, an associate professor of obstetrics and gynecology at The Ohio State University College of Medicine who has studied obstetrical folklore, said the findings offer good support for the idea that sex won't induce labor.

Earlier research had relied primarily on surveys of women about their sexual experiences during pregnancy, but this study was "the first attempt to really randomize the experience, for some to have sex and some to not, which is a very hard thing to do," he said. Schaffir wouldn't advise his patients to have sex for the express purpose of going into labor, he added, but the study did indicate that there aren't any hazards to it.

IE 11 is not supported.