CESAREAN DELIVERY

There are two ways that a baby can be born. The most common way is through the mother's birth canal. This is known as vaginal birth. The other way is by means of incisions made in the mother's abdominal wall and her uterus (womb). This method is called cesarean delivery, or cesarean birth. In the United States, about one out of every five births is by the cesarean method, although this proportion varies depending upon the year, the region of the country, and some other factors. In some South American countries the cesarean delivery rate is as high as 50 percent or more.

Historical Overview

The origin of the term "cesarean birth" or "cesarean section," as it is often called, is disputed. Clearly, the name does not come from the Roman emperor Julius Caesar having been born by such an operation. In his day this operation was fatal to the mother, and it is known that Caesar's mother survived his birth. There are references to abdominal birth in Roman documents dating to as early as 715 B.C.E. when it was mentioned as the Lex Regis, or Law of the King: If a pregnant woman died, the baby was to be delivered as quickly as possible through an abdominal incision to save its life. In the time of the Caesars this law became the Lex Cesare, from which the modern name for cesarean birth may have been derived. Also "cesarean" may have been derived from the Latin word cadere, which means "to cut." Furthermore, in Rome children born by abdominal delivery were referred to as caesones. Because of the high maternal death rate from cesarean births, the operation was rarely performed until the twentieth century, when modern surgery was improved with the development of anesthesia and the means to control hemorrhage and to prevent and treat infection. By 1950 it was possible for a hospital in New York City to report that 1,000 consecutive cesarean deliveries had been performed without a single maternal death.

Shifting Reasons for Cesarean Delivery

Until 1970 cesarean births accounted for fewer than one in twenty births in the United States. The reason cesarean births were performed was largely for conditions that threatened the life of the mother. These conditions included uterine hemorrhage, hypertension of pregnancy, tuberculosis, diabetes, heart disease, and prolonged labor caused by disproportion between the size of the infant and the size of the birth canal. A small proportion of the cesarean births were performed because the baby (fetus) was in danger of hypoxia (lack of oxygen) as when the umbilical cord slips out of its normal position. Also, some cesarean deliveries were performed as repeat cesarean births for women who had a previous baby by cesarean, because it was believed that once a cesarean had been performed, all subsequent births should be by cesarean delivery.

In the early 1970s, electronic means of continuously monitoring a baby's heart rate during labor became available, and intensive care for newborns was beginning to result in dramatic improvements in the survival of seriously ill infants. In addition, the frequency of serious maternal complications of cesarean birth had continued to decline. As a result of these improvements in the care of mothers and infants, doctors became more inclined to recommend cesarean delivery in situations where either the mother or infant were at any increased risk of illness or long-term developmental abnormality that might be caused by vaginal birth. For example, before 1970 almost all breech births (in which the buttocks or feet of a baby rather than its head are the first to be born) were by vaginal delivery, but by 1988 almost all such births were by cesarean delivery. The increase in the use of cesarean delivery to prevent harm to the fetus from labor and vaginal delivery accounted for the increase in the cesarean birthrate from 5 percent of live births in 1970 to 25 percent in 1988. After 1988 the rate of cesarean birth began to decline somewhat so that by 1996 it was 21 percent.

One of the common reasons for cesarean birth is repeat cesarean delivery, which accounts for approximately 25 percent of all cesarean births. Women who have had a cesarean delivery are at risk of the uterine incision rupturing during labor. This can result in the death of or the serious injury to the infant and life-threatening hemorrhage and possible need for a hysterectomy for the mother. The risk of uterine rupture depends upon the type of uterine incision. A vertical incision in the uppermost portion of the uterus has a 12 percent risk of rupturing during labor. This type of incision was used commonly in the early part of the twentieth century but now is used only on rare occasions. A woman who has had a cesarean birth by this method should have all subsequent births by cesarean delivery before the onset of labor to avoid a catastrophic rupture of the uterus. A transverse incision in the lower portion of the uterus, which is now the most common method of performing a cesarean delivery, is associated with a 0.5 percent risk of rupture during labor. Most women who had this type of cesarean delivery can safely attempt a trial of labor and vaginal delivery provided that labor occurs where there are facilities for and personnel who can perform an immediate cesarean delivery if signs of uterine rupture occur. The increase in the incidence of vaginal birth after a previous cesarean birth accounted for the gradual decline in the cesarean delivery rate after 1988.

The Cesarean Operation

The cesarean operation, which usually takes from thirty to sixty minutes, begins with the administration of anesthesia by use of intravenous and inhaled anesthetic agents (general anesthesia) or the injection of anesthetic medications into the spinal canal (spinal anesthesia) or just outside of the spinal canal (epidural anesthesia). The skin of the abdomen is cleansed with antiseptic solution and surgical drapes are placed to maintain a sterile operating field during the procedure. An incision is made in the abdomen, after which a second incision is made in the uterus (womb) that is large enough to permit removal of the baby. The umbilical cord is clamped and cut, and the infant is handed to a nurse or doctor assigned specifically to care for the infant. The placenta (afterbirth) is then delivered through the same incisions. The incisions are closed with sutures (stitches) or other types of wound-closure devices. The expense of a cesarean birth is about two to three times that of a vaginal birth because of the additional personnel, equipment, and time required for performing the operation and the somewhat longer hospital stay following the birth.

Complications Related to Cesarean Delivery

Complications of the birth process may affect either the mother or the infant. Whereas the risk of complications for the mother is somewhat greater in a cesarean birth than in a vaginal birth, the risk of complications for the infant is greater from vaginal birth than from cesarean birth. Moreover, the type and severity of complications from each method of birth differs for both the mother and the infant. Complications of cesarean birth for the mother during the operative procedure include adverse reactions to anesthetic agents, injury of abdominal organs and hemorrhage from the surgical incisions; and after the procedure, pneumonia, urinary or wound infections, and blood clots in the legs, abdomen, or lungs. The most common long-term complication of cesarean birth is the risk of rupture of the uterine incision in a subsequent pregnancy, and the consequent increase in risk of future pregnancies having to be delivered by cesarean.

Complications of vaginal birth for the mother include many of the complications that occur in cesarean birth, but they occur much less often and are usually less severe. The long-term complication of vaginal birth is the increased risk of pelvic muscle dys-function that manifest as urinary or rectal incontinence.

Overall, the risk of maternal death from a cesarean birth (4 per 10,000 births) is four times greater than from a vaginal birth (1 per 10,000 births). Cesarean births, however, are often performed for medical or obstetrical complications that, by their nature, increase the risk of death for mothers. If one excludes pregnancies with such complications, there still remains a one and one-half times greater risk of the mother dying as a result of cesarean birth as compared to vaginal birth.

Complications of vaginal birth for an infant include birth trauma (fractured limbs or injured nerves resulting in paralysis of an arm), asphyxia (lack of oxygen) causing brain damage, and acquiring an infection from the mother's birth canal (herpes simplex virus or group-Bstreptococcus). Complications of cesarean birth for infants include lacerations from the surgeon's knife and a respiratory illness caused by the failure of excess fluid to be cleared from the infant's lungs.

Balancing the benefits and risks of vaginal birth as compared to cesarean birth for both the mother and the infant in a wide variety of birthing situations is the complex problem faced by doctors and midwives, who care for women during their pregnancies. Increasingly, women are becoming more involved in the decisions about the way in which they will give birth. During her pregnancy, a woman should be provided with accurate and updated information about the benefits and risks of the alternative methods of delivery for her situation so that together with her physician or midwife she can make an informed decision about the method of birth.

See also:BIRTH; MIDWIVES

Bibliography

Bowes, Watson, Jr. "Clinical Aspects of Normal and Abnormal Labor." In Robert Creasy and Robert Resnik eds., Maternal-Fetal Medicine, 4th edition. Philadelphia: Saunders, 1999.

Hankins, Gary, Steven Clark, F. Gary Cunningham, and Larry Gilstrap. "Cesarean Section." InOperative Obstetrics. Norwalk, CT: Appleton and Lange, 1995.

Phelan, Jeffrey, and Steven Clark, eds. Cesarean Delivery. New York:Elsevier, 1988.

Watson A.BowesJr.