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Pregnancy Labor Induction

The Use of Prostaglandins for Induction of Labor

Prostaglandins are commonly used as a method of pregnancy labor induction. We provide a list of five methods of prostaglandin use for inducing labor.

What are Prostaglandins?

Prostaglandins are fatty acids that have a hormone-like effect on cells. Prostaglandins impact numerous systems in the body, but are particularly known for the softening-effect they have on the cervix. Before labor, the cervix softens in a process called ripening, which makes the cervical tissue more pliable and uterine contractions effective in causing dilation.

Due to the effectiveness in prostaglandin agents in softening the cervix and even causing contractions, they are used medically to induce labor. Natural prostaglandins may also be used by the mother to soften her cervix, and, if her body is ready, perhaps even entice labor contractions to begin.

Prostaglandins for Natural Labor Induction


Prostaglandins are present in semen, a fact which has produced two common recommendations in pregnancy.

First, women who have been experiencing contractions that may lead to preterm labor have been put on pelvic rest, a term indicating she should avoid sexual contact. The prostaglandins in the semen and the uterine contractions that come with sexual stimulation and orgasm could start labor if the body’s hormones are prepared for it. In order to avoid a premature delivery, women are advised not to have sexual contact if they appear at risk for preterm labor.

But on the other hand, some women who are full term and wanting to assist their body in starting labor, have found that sexual intercourse is helpful for the very same reasons: the prostaglandins in the semen help to soften the cervix, and the uterine stimulation may start contractions.

Many women have used their partner's semen as a pregnancy labor induction method.

Evening Primrose Oil

Another way of utilizing prostaglandins is with Evening Primrose Oil. Evening Primrose Oil is a supplement available at pharmacies and health food stores.

Evening Primrose Oil is rich in gamma linolenic acid (GLC) which converts linolenic acid into prostaglandin. It can be taken orally 500 mg of Evening Primrose Oil three times a day after 37 weeks of pregnancy in order to boost prostaglandin levels.

At the same time, one capsule can be inserted at bedtime each night in the vagina near the cervix. The warmth and fluid of the vagina will melt the capsule and apply the gel to the cervical tissue.

Evening Primrose Oil is also available as a cold expressed massage oil. Generally, it is added to a base oil to make up 10% of the total massage oil. However, during labor Evening Primrose Oil can be used full strength to strengthen contractions that started on thier own.

Neither sexual intercourse or Evening Primrose Oil are considered risky and in need of a physician’s order; however, most health care providers advise that a mother discuss her plans to enhance cervical ripening with them. In a few situations, such as uncertainty regarding gestational age, there may be reasons to avoid stimulating the cervix.

Prostaglandins for the Medical Labor Induction

Medically, prostaglandins may be used by medical professionals to ripen the cervix for pregnancy labor induction. The page on pitocin labor induction gives more information on the use of prostaglandin products as cervical ripening agents.. These prostaglindin softening agents include Prepidil gel, Cervidal pessary, and Cytotec tablets. All are placed in or near the cervix during a vaginal exam.

Due to increased strength and risk of these agents, federal law allows them only to be used by qualified clinicians. Laws differ from state to state as to what qualifications are required, but in the United States most states limit their use to physicians and certified nurse midwives.

The use of prostaglandin for enhancing cervical softening and strengthening contractions can be used by any of the applications mentioned above for pregnancy labor induction. It is possible to start with the least interventive techniques (such as sexual intercourse or massage with Evening Primrose Oil) and then use the more interventive techniques if these are ineffective (gels, pessary or Cytotec tablets.)

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By Karen Newell Copyright 2003 - 2012 Better Childbirth Outcomes - All Rights Reserved
Camp Hill, Pennsylvania, USA