Induction of labor is the artificial starting of labor. Usually, labor is induced by giving the woman oxytocin, a hormone that makes the uterus contract more frequently and more forcefully. The oxytocin given is identical to the natural oxytocin produced by the pituitary gland. It is given intravenously with an infusion pump, so that the amount of drug given can be controlled precisely. Sometimes prostaglandins, which help the cervix open (dilate), are also given to help start labor. Alternatively, a tube (catheter) with a balloon attached can be inserted in the cervix. The balloon is then inflated to dilate the cervix.

Throughout induction and labor, the fetus's heart rate is monitored electronically. At first, a monitor is placed on the woman's abdomen. After the membranes are ruptured, an internal monitor may occasionally be inserted through the vagina and attached to the fetus's scalp. If induction is unsuccessful, the baby is delivered by cesarean.

Augmentation of labor is the artificial hastening of labor that is proceeding ineffectively or too slowly. Oxytocin is used to augment labor. Labor is augmented when women have contractions that are not effectively moving the fetus through the birth canal.

Slowing of labor is the artificial delaying of labor that is proceeding too forcefully. Very rarely, a woman has contractions that are too strong, too close together, or both. If contractions are caused by the use of oxytocin, the drug is stopped immediately. The woman may be repositioned and given analgesics. If the contractions occur spontaneously, a drug that can slow labor (such as terbutaline or ritodrine) may be given to stop or slow the contractions.

A vacuum extractor consists of a small cup made of a rubberlike material that is connected to a vacuum. It is inserted into the vagina and uses suction to attach to the fetus's head. A vacuum extractor is occasionally used in a normal labor to ease delivery. If vacuum extraction delivery is tried and is unsuccessful, cesarean delivery is done. Rarely, a vacuum extractor bruises the baby's scalp or causes bleeding in the baby's eyes (retinal hemorrhage). The risk of shoulder dystocia and jaundice is also increased.

Forceps are metal surgical instruments with rounded edges that fit around the fetus's head. Forceps are occasionally used instead of a vacuum extractor in a normal labor to ease delivery. Rarely, using forceps bruises the baby's face or tears the woman's vagina.

Vacuum extraction or forceps delivery may be required in the following situations:

• When the fetus is in distress
• When the woman is having difficulty pushing
• When labor is prolonged
• When the woman has a disorder (such as some brain or heart disorders) that make vigorous pushing inadvisable

Using Forceps or a Vacuum Extractor Forceps or a vacuum extractor may be used to help with delivery. Forceps are placed around the baby's head. A vacuum extractor uses suction to adhere to the baby's head. With either device, the baby is gently pulled out as the woman pushes.

Cesarean Delivery

Cesarean delivery is surgical delivery of a baby by incision through a woman's abdomen and uterus.

In the United States, about 2 to 3 in 10 deliveries are cesarean.

Doctors use a cesarean delivery when they think it is safer than vaginal delivery for the woman, the baby, or both, as in the following situations:

• When the woman has had a previous cesarean delivery
• When labor is prolonged
• When the fetus is in an abnormal position, such as breech presentation (buttocks first)
• When fetal distress requires quick delivery

An obstetrician, an anesthesiologist, nurses, and sometimes a pediatrician are involved in this surgical procedure. Use of anesthetics, intravenous drugs, antibiotics, and blood transfusions helps make a cesarean delivery safe. Having the woman walk around soon after surgery reduces the risk of blood clots forming in the legs or pelvis, traveling to the lungs, and blocking arteries there (pulmonary embolism). Cesarean delivery results in more overall pain afterward, a longer hospital stay, and a longer recovery time than vaginal delivery.

For a cesarean delivery, an incision can be made in the upper or lower part of the uterus.

• Lower incision: This type of incision is more common. The lower part of the uterus has fewer blood vessels and so less blood is usually lost. Also, the healed scar is stronger, so that it is less likely to open in subsequent deliveries. A lower incision may be horizontal or vertical.
• Upper incision: Usually, this incision is used when the placenta covers the cervix (a complication called placenta previa), when the fetus lies horizontally across the birth canal, when the fetus is in breech presentation, or when the fetus is very premature.

The choice of having a vaginal delivery or a repeat cesarean delivery is usually offered to women who have had a lower incision. Vaginal delivery is successful in about three fourths of these women. However, such women should plan to have their baby in facilities equipped to rapidly do a cesarean delivery because there is a very small chance that the incision from the previous cesarean section will open during labor.

Last full review/revision December 2008 by Julie S. Moldenhauer, MD