Cesarean Delivery

Definitions

Cesarean delivery (CD) is defined as birth of a fetus from the uterus through an abdominal incision. The terms cesarean delivery or cesarean birth are preferred as opposed to cesarean section . Primary cesarean refers to a CD in a woman without a prior cesarean birth, whereas repeat cesarean refers to a CD in a woman who had a cesarean birth in a previous pregnancy. This chapter reviews the history, incidence, indications, techniques, and complications of CD as well as tubal sterilization.

History of Cesarean Delivery

CD has been described since ancient times, and evidence exists from both early Western and non-Western societies of this surgical procedure being performed. The evolution of the term cesarean has been debated over time. Although originally believed to have been derived from the birth of Julius Caesar, it is unlikely that his mother, Aurelia, would have survived the operation; her knowledge of her son's invasion of Europe many years later indicates that she survived childbirth. In Caesar's time, surgical delivery was reserved for when the mother was dead or dying. Roman law under Numa Pompilius I (“Lex Regia”), then renamed after Caesar (“Lex Cesarea”), specified surgical removal of the fetus before burial of the deceased pregnant woman; religious edicts required separate burial for the infant and mother. The term cesarean may also refer to patients being cut open, because the Latin verb caedare means to cut. Cesarean operation was the preferred term before the 1598 publication of Guillimeau, who introduced the term section .

Although sporadic reports of heroic life-saving efforts through cesarean childbirth existed for hundreds of years, it was not until the latter part of the 19th century that the operation became established as part of obstetric practice. This coincided with the gradual transition of childbirth as primarily a midwife-attended event, often in rural settings, to an urban maternity hospital experience. The wide emergence of maternity hospitals in Europe during the 18th and 19th centuries laid the foundation for establishing obstetrics as a hospital-based specialty.

As new methods for pain relief such as laudanum syrup and chloroform anesthesia emerged, CD for obstructed labor gained popularity over destructive procedures, such as craniotomy, or high forceps delivery, which were often associated with significant fetal injury, deep maternal pelvic lacerations and permanent damage to the maternal bladder and anal sphincter. However, mortality rates for CD remained very high, with sepsis and hemorrhage as leading causes of postoperative deaths. Primitive surgical techniques and lack of antisepsis clearly contributed to morbidity. Surgeons attempted to complete the operation without closing the uterus, fearing that the suture material itself would promote infection and that the uterus would best heal by secondary intention.

Lebas first advocated suturing the uterus after CD in 1769. Traditionally, sutures were not used inside the abdomen or pelvis because they were considered impossible to remove once the cavity was closed. In 1876, Eduardo Porro advocated for supracervical hysterectomy and bilateral salpingo-oopherectomy during CD to control bleeding and to prevent postoperative infection. Shortly thereafter, surgeons gained experience with internal suturing using the silver-wire stitches developed by the gynecologist J. Marion Sims, who had perfected the use of these sutures in the treatment of vesicovaginal fistulae resulting from obstructed labors. In the early 1880s, two German obstetricians, Ferdinand Adolf Kehrer (1837–1914) and Max Sänger (1853–1903), both independently proposed a transverse incision of the lower segment of the uterus, just above the level of the internal cervical os, and developed two-layer uterine closure methods. Another pivotal contribution was made in 1900 by Hermann Johannes Pfannenstiel (1862–1909), a German gynecologist who described a transverse suprapubic incision, or pelvic skin incision.

As gynecologic surgeons performed more CDs and outcomes improved, greater attention was placed on technique, including the site of the uterine incision. Between 1890 and 1925, more and more surgeons began using transverse incisions of the uterus. John Martin Munro Kerr (1868–1960), a professor of midwifery at the University of Glasgow, popularized the Pfannenstiel skin incision and lower segment uterine incision and is considered the “father” of the modern CD. It was noted that such incisions reduced the rate of infection and the risks of incisional hernia and uterine rupture with subsequent pregnancies compared with the vertical incisions. However, before the advent of antibiotics, owing to the risk of peritonitis, extraperitoneal cesarean was advocated by Frank (1907), Veit and Fromme (1907), and Latzko (1909), and was popularized by Beck (1919) in the United States. Interestingly, the vertical opening of the abdomen was still the principal technique used in the 1970s, although it was known from the beginning of the 20th century to be associated with higher rates of long-term postoperative complications, such as wound dehiscence and abdominal incision hernia, and it is also cosmetically inferior.

The introduction of penicillin in the 1940s dramatically reduced the risk of peripartum infections. As antibiotic therapy emerged, the need for extraperitoneal dissection diminished. As technology developed, including improved anesthesia, use of uterotonics, and access to blood transfusion, CD became more commonplace in obstetrics. Given its current safety and effectiveness, a liberalized approach to using cesarean childbirth has emerged in developed countries over the past 40 years.

Incidence

The CD rate describes the proportion (prevalence) of women undergoing CD of all women giving birth during a specific time period. The CD rate may be further subdivided into primary and repeat CD rates, both as a proportion of the entire obstetric population. CD rates have risen in the United States in a dramatic fashion from less than 5% in the 1960s to 32% by 2017, with stable rates around 31% to 33% in the last 10 years or so. CD accounts for more than 1 million major operations performed annually in the United States. It is the most common major surgical procedure undertaken today in the United States and around the world. Among the reasons for this increase are (1) a continued increase in primary CDs for dystocia, failed induction, reduced operative vaginal delivery, and malpresentation (e.g., breech); (2) an increase in the proportion of women with obesity, diabetes mellitus, and multifetal gestation; (3) increased practice of CD on maternal request; and (4) limited use of a trial of labor after cesarean (TOLAC) delivery due to both safety and medicolegal concerns. Factors responsible for increased cesarean rates are shown in Box 19.1 .

A recent increase in international CD rates has also been documented. Rates of about 25% to 30% are reported in some European countries, such as the United Kingdom; they are over 40% in Italy, between 40% and 50% in China (which has seen a recent decrease), and over 50% in countries like Brazil, Mexico, Turkey, and Egypt. The rise in CD rates has prompted increased interest in the indications, complications, and techniques involved with this procedure.

The World Health Organization (WHO) has proposed a population incidence of CD between 10% and 15% as a target to optimize maternal and perinatal health. However, it is not possible to determine an optimal CD rate because any ideal rate must be a function of multiple clinical factors, for example, maternal age, maternal obesity and other comorbidities, and artificial reproductive technology, all of which vary in and within each population, and are influenced by medicolegal issues, practice style, and access to different levels of obstetric care. Further complicating this issue is the absence of complete and accurate data that focus on both maternal and infant outcomes. Hence, although CD rates can be considered a measure of a specific healthcare process (mode of delivery), these rates are not appropriate outcome measures because they do not indicate whether cesarean or vaginal birth results in optimal perinatal outcomes. Maternal and perinatal morbidity and mortality should be the outcomes monitored to ensure best quality of care. Higher CD rates (e.g., 15% to 20% compared with <5% to 10%) have been associated with better perinatal outcomes in several studies. Thus, instead of setting goals or limits for overall CD rates, it is most important to monitor maternal and perinatal health outcomes. The optimal CD rate in the early 21st century depends on the population. For example, Robson has suggested a helpful classification of different populations to compare cesarean rates. Class I is the most common class in most centers and includes singleton term vertex gestations admitted in spontaneous labor. Only by comparing data for similar Robson classes, or at least a similar case mix, can data regarding CD rates be objectively evaluated. Moreover, institutions involved in tertiary obstetric care that manage a large number of preterm deliveries and maternal complications of pregnancy should have higher cesarean rates than primary care facilities. Two populations often targeted for comparison include nulliparous women with a singleton vertex gestation at 37 weeks or greater without other complications and women with one prior low transverse CD delivering a single vertex fetus at 37 weeks or greater without other complications. The use of these simple case-mix adjusted rates makes comparative evaluation of CD rates and their comparison to maternal and perinatal outcomes more meaningful.

In 2014, the American College of Obstetricians and Gynecologists (ACOG) and the Society for Maternal-Fetal Medicine (SMFM) published an obstetric care consensus document on the safe prevention of primary CD in which several interventions were suggested to prevent unnecessary CDs ( Box 19.2 ). Institutions can indeed safely reduce cesarean birth rates through quality-improvement initiatives.

Indications for Cesarean Delivery

CD can be performed for maternal-fetal, fetal, and maternal indications. The most common current indications are, in order of frequency, (1) failure to progress, also called cephalopelvic disproportion (CPD) or dystocia (about 30%); (2) prior cesarean (30%); (3) nonreassuring fetal heart rate (FHR) patterns (10% to 20%); and (4) fetal malpresentation (5% to 10%). Indications are listed by category in Box 19.3 . Considering just the first CD, the common indications are shown in percentages in Fig. 19.1 .