Labor Induction

As Shakespeare may have put it: "To induce or not to induce, that is the question." The rate of labor inductions has been increasing steadily over the last 10 years such that nationwide almost 20% of labor is induced compared to 10% in 1989. Some inductions of labor are medically indicated however some are elective, as they are performed solely for the convenience of the mother. It is the elective induction of labor, performed in the absence of medical or obstetric indications, which is most controversial.

There are many medical and obstetric indications for labor induction. In general if it is felt that continuing the pregnancy poses risks to either the mother or baby then induction will be advised. Some obstetric indications for labor induction are preeclampsia, growth restriction of the fetus (when the baby isn’t growing properly), Post dates pregnancy (more than 41-42 weeks gestation) an infection of the uterus (chorioamnionitis) and premature rupture of the membranes. Medical conditions of the mother that might warrant induction include high blood pressure, diabetes, lung or kidney disease. Sometimes labor is induced because of logistic reasons such as living a long way from the hospital or a history of very fast labors. These inductions are not particularly controversial, it is the purely elective induction done for the convenience of the mother and possibly her physicians that generate controversy.

Supposed benefits to elective induction of labor include escaping the discomforts of the last weeks of pregnancy, scheduling of work, childcare or other commitments, availability of other support people, effecting a delivery during daylight hours when both mother and her caregivers are less tired. If an induction is relatively short and easy these are worthy reasons for induction. However if the induction is long or results in complications for mother or baby then the indications need to be reevaluated. Because of potential complications associated with any induction method the mother has to be continuously monitored which may prevent walking during labor. Some women feel that an induced labor is more painful than natural labor. The medical literature has many studies looking at induction of labor; it appears that the cesarean section rate is higher in induced labors than spontaneous labor. Assuming a term fetus and appropriate monitoring it is as safe as spontaneous labor for the fetus.

The most important consideration before starting an induction is determining if the baby is ready to be born. Elective inductions are not performed before the 39^th week of pregnancy to avoid delivering a premature baby. Next is determining if induction of labor is safe for the mother. An induction is more likely to be successful if the cervix is favorable. This refers to several parameters: dilation, effacement, position and consistency of the cervix and the station of the fetus. In general as the cervix becomes softer, more dilated, easier to reach and the baby’s head descends into the pelvis the more likely the induction is to work. These factors have been quantified into something called the Bishop score. If the Bishop score is more than 8 then the chances the induction will result in a vaginal delivery are the same as spontaneous labor. The lower the Bishop score the less likely the induction is going to be successful.

There are several methods for inducing labor. With a favorable cervix oxytocin (also called Pitocin) is used. This is given through an intravenous catheter and, if the uterus is ready, will cause contractions similar to spontaneous labor. If the cervix is sufficiently dilated rupturing the membranes (amniotomy) can be used instead of or in conjunction with oxytocin. With an unfavorable cervix prostaglandin containing medications are used to "ripen" the cervix and make it more conducive to induction with oxytocin. Although prostaglandins will successfully "ripen" the cervix and lead to a higher bishop score it is not clear that their use decreases the cesarean section rate in women who need to have labor induced.

If an induction of labor is not successful then what happens? Depending on the clinical circumstances a cesarean section is performed or the mother goes home and either awaits spontaneous labor or the induction is tried again at a later date. Needless to say the latter can be quite frustrating to the mother who has spent hours in the hospital hoping to have her baby on that particular day.

When discussing labor induction remember that the most important issue is whether the induction is in the best interest of you and your baby. A thorough understanding of the benefits and risks of labor induction is important for any woman considering elective labor induction.