Cesarean Delivery

INTRODUCTION

The phrase cesarean delivery is defined as the delivery of a fetus through a surgical incision through the abdominal wall (laparotomy) and uterine wall (hysterotomy). In the United States, it is customary to use only the letter e in the first syllable of cesarean. In Australia and England, the letters a and e still are used (ie, caesarean).

The words cesarean and section both are derived from verbs that mean to cut; thus, the phrase cesarean section is a tautology. It is preferable to use the terms cesarean delivery or cesarean birth.

In the United States, cesarean delivery has become the most common surgical procedure. By the early 1990s, almost 25% of all live births were from cesarean deliveries. In the last decade, acceptance has been growing for allowing women to have a vaginal delivery after having had a prior cesarean delivery.

History of the Procedure: The exact origin of the term cesarean is unclear. The term cesarean may have arisen in the Middle Ages from the Latin verb caedere (to cut). Children of such births were referred to as caesones. The term also may originate with an eighth century BC Roman law, lex regis. Later called lex cesarea, this law mandated a postmortem operative delivery so that both the mother and child could be buried separately.

Although many references to abdominal delivery are made in many cultures, many of the ancient medical writers (eg, Galen, Hippocrates, Soranus) do not describe such a procedure.

In 1581, Fran蔞is Rousset wrote about cesarean deliveries. He describes 14 such procedures from information he received from letters, but he never actually witnessed such a procedure. By the mid 17th century, more reports by obstetricians about this operation began to appear. Early descriptions of such procedures reveal that abdominal delivery was performed in rare circumstances.

The ability of obstetricians to perform the procedure was limited by anesthesia and infection control. In 1846, the anesthetic agent diethyl ether was introduced at Massachusetts General Hospital. Queen Victoria delivered Leopold (1853) and Beatrice (1857) by cesarean delivery with the administration of chloroform. However, despite the increased potential for abdominal procedures provided by anesthesia, mortality from the procedure from infectious morbidity remained high following cesarean delivery.

Surgical technique also was a limiting factor for the acceptability of the procedure. Initially, maternal mortality from blood loss also was high because surgeons were reluctant to close the uterine incision. Some advocated hysterectomy at the time of cesarean delivery to control bleeding and decrease infection. In 1882, Max Sanger, from Leipzig, described the value of suturing the uterine wall with silver wire (developed by 19th century gynecologist J. Marion Sims) and silk in a 2-step closure. His report documented the survival of 8 of 17 mothers delivered by American surgeons.

Although the introduction of internal sutures decreased hemorrhagic morbidity, infectious morbidity from peritonitis remained substantial. In 1907, the extraperitoneal approach was first described by Frank and modified in 1909 by Latzko. This approach appeared to decrease the risk of peritonitis, and, in 1912, Kr霵ig described that this approach also allowed access to the thinner lower uterine segment. Kr霵ig described a vertical median uterine incision with delivery aided by forceps. Then, the lower segment was covered with peritoneum.

This technique was modified further and introduced in the United States by Beck (1919) and DeLee (1922). Finally, in 1926, Kerr described a low transverse incision in the lower uterine segment, the most commonly used uterine incision throughout the world today. With the discovery of penicillin by Alexander Fleming in 1928 (purified in 1940), the need for an extraperitoneal procedure essentially was eliminated.

INDICATIONS

A cesarean delivery is recommended to prevent maternal and/or fetal morbidity when a contraindication to allowing labor is present or when a completion of a vaginal delivery is anticipated to be unsafe or lengthy. Some indications are for maternal benefit alone, some are for fetal benefit alone, and some are for both maternal and fetal benefit.

Maternal indications

Relatively few indications for a cesarean delivery solely benefit the mother.

• Women with an abdominal cerclage in place: Those mothers with an incompetent cervix in whom vaginal cervical cerclages have failed but who wish to have more children should have a cesarean delivery.

  　

• Obstructive lesions in the lower genital tract: Cesarean delivery would be performed in the setting of obstructive lesions in the lower genital tract, including malignancies and large vulvovaginal condyloma.

  　

• Women with prior vaginal colporrhaphy and major anal involvement from inflammatory bowel disease: These patients would be candidates for an outright cesarean delivery.

Fetal indications

Fetal indications for cesarean delivery include those in which neonatal morbidity and mortality could be decreased by the prevention of trauma, infection, and prolonged acidemia.

• Malpresentation: A fetus in a nonvertex presentation is at increased risk for trauma, cord prolapse, and head entrapment. Malpresentation includes preterm breech presentations and nonfrank breech term fetuses. A randomized controlled trial assessing the safety of term breech deliveries has been completed and is awaiting publication. Furthermore, in twin gestations, a second twin in a nonvertex presentation is a relative indication for an outright cesarean delivery, as are higher order multiples (triplets or greater).

  　

• Congenital anomalies: A cesarean delivery is recommended for several congenital anomalies; these include fetal neural tube defects, some cases of hydrocephalus, and some skeletal dysplasias. Whether or not an outright cesarean delivery should be performed in the setting of a fetal abdominal wall defect (ie, gastroschisis and omphalocele) remains controversial.

  　

• Nonreassuring fetal heart rate: In the setting of a nonremediable and nonreassuring pattern remote from delivery, a cesarean delivery is recommended to prevent a mixed metabolic or metabolic acidemia that could potentially cause significant morbidity and mortality.

  　

• Genital herpes infections: Mothers with an active vaginal herpes infection (especially with primary outbreak) are candidates for cesarean delivery. Neonatal infection with herpes can lead to significant morbidity and mortality, especially with a primary outbreak. With recurrent outbreaks, the risk to the neonate is reduced by the presence of maternal antibodies. Unfortunately, not all women with active viral shedding can be detected upon admission to labor and delivery.

  　

• Human immunodeficiency virus infections: Treatment of women with the human immunodeficiency virus has undergone tremendous change in the past few years. Women with a low CD4 count and high viral titers should be offered cesarean delivery at 38 weeks (or earlier if they go into labor). In women who are being treated with antiretrovirals, cesarean delivery (prior to labor or without prolonged rupture of membranes) appears to further lower the risk for neonatal transmission.

Maternal and fetal indications

Indications for cesarean delivery that benefit both the mother and the fetus include abnormal placentation, abnormal labor due to cephalopelvic disproportion, and those situations in which labor is contraindicated.

• Abnormal placentation: In the presence of a placenta previa (ie, the placenta covering the internal cervical os), attempting vaginal delivery places both the mother and the fetus at risk for hemorrhagic complications.

  　

• Abnormal labor due to cephalopelvic disproportion: Cephalopelvic disproportion can be suspected on the basis of possible macrosomia or an arrest of labor despite augmentation. Continuing to attempt a vaginal delivery in this setting increases the risk of hemorrhagic and metabolic consequences from a uterine rupture, increases the chance of infectious complications to both mother and fetus from prolonged rupture of membranes, and increases the risk of maternal trauma and fetal trauma (eg, Erb or Klumpke palsy and metabolic acidosis) from a shoulder dystocia.

  　

• Contraindications to labor: In women who have a uterine scar (prior myomectomy in which the uterine cavity was entered or cesarean delivery in which the upper contractile portion of the uterus was incised), a cesarean delivery should be performed to prevent the risk of uterine rupture.

WORKUP

Lab Studies:
　

• When patients are admitted for labor and delivery, most have blood for a CBC count and type and screen drawn when an intravenous line is started (a basic requirement for patients when they are admitted to the labor floor). If a patient has a hemoglobin level within the reference range, has had an uncomplicated pregnancy, and is anticipated to have a vaginal delivery, the use of having blood submitted to the lab for a routine CBC count and type and screen currently is being scrutinized from a cost-benefit standpoint. In many centers, blood is drawn and simply held in case the patient's course changes. Namely, if the decision is made to perform a cesarean delivery for an abnormal labor course, nonreassuring fetal testing, or abnormal bleeding, then the blood work is submitted.

• The following are several situations in which a CBC count and type and screen always will be submitted upon admission to labor and delivery:

• If a patient is admitted for a planned cesarean delivery

• A grand multipara

• History of postpartum hemorrhage

• History of a bleeding disorder

• On occasion, a coagulation profile is ordered. In patients with thrombocytopenia, a history of a bleeding disorder, or preeclampsia, coagulation studies (prothrombin time and activated partial thromboplastin time) may be ordered to assist the attending anesthesiologist in determining the safety of attempting regional anesthesia with an epidural or spinal procedure.

• On occasion, a patient has a specimen crossmatched, with blood available. The most common situation is a patient who has had several prior laparotomies (including several prior cesarean deliveries) or one who develops a coagulopathy from either severe preeclampsia or significant hemorrhage.

TREATMENT

Medical therapy: As stated, many indications exist for performing a cesarean delivery. In those women who are having a scheduled procedure (ie, an elective or indicated repeat, for malpresentation, placental abnormalities), the decision has already been made that the alternate of "medical therapy," ie, a vaginal delivery, is least optimal. For other patients admitted to labor and delivery, the anticipation is for a vaginal delivery. Every patient admitted in this circumstance is admitted with the thought of a successful vaginal delivery. However, if the patient's situation should change, a cesarean delivery is performed because it is believed that outcome for the fetus and/or mother may be better.

If a patient is diagnosed with a fetal malpresentation (ie, breech or transverse lie) after 36 weeks, the option for an external cephalic version is offered to try to convert the fetus to a vertex lie, thus allowing an attempt at a vaginal delivery. An external cephalic version usually is attempted at 36-38 weeks. The patient usually is observed in close proximity to the labor and delivery unit or in the labor and delivery unit itself. The patient has been asked to not eat for 8 hours prior to the procedure. An ultrasound is performed to confirm fetal presentation. If the fetus is still in a nonvertex presentation, an intravenous line is started and the baby is monitored with an external fetal heart rate monitor.

If fetal heart rate testing is reassuring, the version is attempted. An external cephalic version involves trying to externally manipulate the fetus into a vertex presentation. Usually, this is accomplished with ultrasound guidance to ascertain fetal lie. An attempt is made to manipulate the fetus through either a "forward roll" or "backward roll." The overall chance of success is approximately 40%. Some practitioners administer an epidural to the patient prior to the attempted version, and others may give the patient a dose of subcutaneous terbutaline (a beta-mimetic used for tocolysis) just prior to the attempt.

Factors that influence the success of an attempted version include multiparity, a posterior placenta, and normal amniotic fluid with a normally grown fetus. Also, to be a candidate, a patient must be eligible for an attempted vaginal delivery. Relative contraindications include poor fetal growth or the presence of congenital anomalies. Risks of an external cephalic version include rupture of membranes, labor, fetal injury, and the need for an emergent cesarean delivery due to possible disruption of the placenta.

If the version is successful, the patient is placed on a fetal monitor. If fetal heart rate testing is reassuring, either the patient is discharged to await spontaneous labor or she is induced if the fetus is of an appropriate gestational age and/or the patient has a favorable cervix.

The anesthesiologist monitors the patient's vital signs and tracks fluid intake and urine output. The average blood loss associated with a cesarean delivery is approximately 1000 cc. A patient at term will have up to a 50% expansion in their blood volume and could lose up to 1500 cc without showing any change in their vital signs. If a significant blood loss is encountered or anticipated, assess the hemoglobin level and crossmatch blood.

Abdominal incision

One option is to use a midline infraumbilical incision to enter the peritoneal cavity. This incision provides quicker access to the uterus. In pregnancy, entry commonly is enhanced by diastasis of the rectus muscles. This incision is associated with less blood loss, easier examination of the upper abdomen, and easy extension cephalad around the umbilicus. If a patient is anticipated to have significant intra-abdominal adhesions from prior surgeries, a vertical incision may provide easier access into the abdomen, with better visualization. Upon reaching the rectus sheath, either the rectus sheath can be incised with a scalpel for the entire length of the incision or a small incision in the fascia can be made with a scalpel and then extended superiorly and inferiorly with scissors. Then, the rectus muscles (and pyramidalis muscles) are separated in the midline by sharp and blunt dissection. This act exposes the transversalis fascia and the peritoneum.

The peritoneum is identified and entered at the superior aspect of the incision to avoid bladder injury. Prior to entering the peritoneum, care is taken to avoid incising adjacent bowel or omentum. Once the peritoneal cavity is entered, the peritoneal incision is extended sharply to the upper aspect of the incision superiorly and to the reflection over the bladder inferiorly.

Most commonly, a transverse incision through the lower abdomen is made. The incision is either a Maylard or, more commonly, a Pfannenstiel incision. Transverse incisions take slightly longer to enter the peritoneal cavity, usually are less painful, have been associated with a smaller risk of developing an incisional hernia, are preferred cosmetically, and can provide excellent visualization of the pelvis.

The Pfannenstiel incision is curved slightly cephalad at the level of the pubic hairline. The incision extends slightly beyond the lateral borders of the rectus muscle bilaterally and is carried to the fascia. Then, the fascia is incised bilaterally for the full length of the incision. Then, the underlying rectus muscle is separated from the fascia both superiorly and inferiorly with blunt and sharp dissection. Clamp and ligate any blood vessels encountered. The rectus muscles are separated in the midline, and the peritoneum is entered.

A Maylard incision is made approximately 2-3 cm above the symphysis and is quicker than a Pfannenstiel incision. It involves a transverse incision of the anterior rectus sheath and rectus muscle bilaterally. Identify and possibly ligate the superficial inferior epigastric vessels (located in the lateral third of each rectus). For most cesarean deliveries, only the medial two thirds of each rectus muscle usually needs to be divided. If more than two thirds of the rectus muscle is divided, identify and ligate the deep inferior epigastric vessels. The transversalis fascia and peritoneum are identified and incised transversely.

Uterine incision

Upon entering the peritoneal cavity, inspect the lower abdomen. The uterus is palpated and commonly is found to be dextrorotated such that the left round ligament is more anterior and closer to the midline. Dissect the bladder free of the lower uterine segment. Grasp the loose uterovesical peritoneum with forceps, and incise it with Metzenbaum scissors. The incision is extended bilaterally in an upward curvilinear fashion. The lower flap is grasped gently, and the bladder is separated from the lower uterus with blunt and sharp dissection. A bladder blade is placed to both displace and protect the bladder inferiorly and to provide exposure for the lower uterine segment (the acontractile portion of the uterus).

One of essentially 2 incisions can be made on the uterus, either a transverse or vertical incision. The decision for the type of incision is based on several factors, including fetal presentation, gestational age, placental location, and presence of a well-developed lower uterine segment. The choice of incision must allow enough room to deliver the fetus without risking injury (either tearing or cutting) to the uterine arteries and veins that are located at the lateral margins of the uterus.

In more than 90% of cesarean deliveries, a low transverse (Monroe-Kerr) incision is made. The incision is made 1-2 cm above the original upper margin of the bladder with a scalpel. The initial incision is small and is continued into the uterine wall until either the fetal membranes are visualized or the cavity is entered (take care to not injure the underlying fetus).

The incision is extended bilaterally and slightly cephalad. The incision can be extended with either sharp dissection or blunt dissection (usually with the index fingers of the surgeon). Blunt dissection has the potential for unpredictable extension, and care should be taken to avoid injury to the uterine vessels. The presenting part of the fetus is identified, and the fetus is delivered either as a vertex presentation or as a breech. With a low transverse incision, the risk for uterine rupture in subsequent pregnancies is approximately 1%, and patients can be counseled about the safety of an attempted trial of labor and vaginal birth.

In some instances, a vertical incision is used. A vertical incision may be used if the lower segment is not well developed (ie, narrow), if an anterior placenta previa is present, or if the fetus is in a transverse lie or in a preterm nonvertex presentation. Again, the bladder has been dissected inferiorly to expose the lower segment, and the bladder blade has been placed.

The vertical incision again is initiated with a scalpel in the inferior portion of the lower uterine segment. Care is taken to avoid injury to the underlying fetus, and the incision is carried into the uterus until the cavity is entered. When the cavity is entered, the incision is extended superiorly with sharp dissection. The fetus is identified and delivered. Note the extent of the superior portion of the uterine incision.

If the incision is confined to the lower acontractile portion, it is considered a low vertical incision and patients can be counseled for a trial of labor and vaginal delivery in subsequent pregnancies. With a true low vertical incision, the risk of uterine rupture with a trial of labor is approximately 1-4%, with most recent reports finding a risk for uterine rupture of less than 2%. If the incision should be either extended into the contractile portion of the uterus or is made almost completely in the upper contractile portion, the risk of uterine rupture in future pregnancies is 4-10% and patients are counseled to undergo a repeat cesarean delivery with all subsequent pregnancies.

A vertical incision also may be considered in those cases where a hysterectomy may be planned in the setting of a placenta accreta or if the patient has a coexisting cervical cancer for which a hysterectomy would be the appropriate treatment. A vertical incision is associated with increased blood loss and longer operating time (takes longer to close) with less risk of injury to the uterine vessels than a low transverse incision.

Delivery

When the fetus is delivered, the umbilical cord is doubly clamped and cut. Blood is obtained from the cord for fetal blood typing, and a segment of cord is placed aside for attaining blood gas results if a concern exists regarding fetal status. Following delivery, oxytocin (20 U) is placed in the intravenous fluid to increase contractions of the uterus. The placenta usually is delivered manually. Awaiting spontaneous delivery of the placenta with gentle traction is more time consuming but is associated with decreased blood loss, lower risk of endometritis, and lower maternal exposure to fetal red blood cells, which can be important to Rh-negative mothers delivering an Rh-positive fetus.

After delivery of the baby, administer prophylactic antibiotics. A single dose of ampicillin or a first-generation or second-generation cephalosporin is appropriate. If the surgery is prolonged, a second dose can be administered later. If the patient has chorioamnionitis, broader-spectrum antibiotics, such as gentamicin and clindamycin or Unasyn, are indicated and should be continued in the postoperative period until the patient is afebrile.

Repair of the uterine incision

Repair of the uterus can be facilitated by manual delivery of the uterine fundus through the abdominal incision. Externalizing the uterine fundus facilitates uterine massage, the ability to assess whether the uterus is atonic, and the examination of the adnexa.

The uterine cavity usually is wiped clean of all membranes with a dry laparotomy sponge, and the cervix can be dilated with an instrument, such as a Kelly clamp, if the patient underwent delivery with a previously undilated cervix. Typically, an Allis clamp is placed at the angles of the uterine incision. The incision is inspected for other bleeding vessels, and any extensions of the incision are evaluated. Inspect the bladder and lower segment inferior to the incision.

Repair of a low transverse uterine incision can be performed in either a 1-layer or 2-layer fashion with zero or double-zero chromic or Vicryl suture. The first layer should include stitches placed lateral to each angle, with prior palpation of the location of the lateral uterine vessels. Most physicians use a continuous locking stitch. If the first layer is hemostatic, a second layer (Lembert stitch), which is used to imbricate the incision, does not need to be placed. A large prospective study has shown no increase in postoperative complications with a 1-layer versus 2-layer closure. Although the risk of uterine rupture with subsequent trials of labor appears to not be increased with a 1-layer closure, the authors await follow-up data from this trial.

Closure of a vertical incision usually requires several layers because the incision is through a thicker portion of the uterus. Again, a heavy suture material is used, and usually the first layer closes the inner half of the incision, with a second and possible third layer used to close the outer half and serosal edges. Again, note the extent of a vertical uterine incision because it impacts how a patient should be counseled regarding future pregnancies.

When the uterus is closed, attention must be paid to its overall tone. An atonic uterus can be encountered in a patient with a multiple gestation, polyhydramnios, or a failed attempt at a vaginal delivery in which the patient was on Pitocin augmentation for a prolonged period. If the uterus does not feel firm and contracted with massage and intravenous oxytocin, consider intramuscular injections of prostaglandin (15-methyl-prostaglandin, Hemabate) or methylergonovine and repeat as appropriate.

Continued closure

If the uterine incision is hemostatic, the uterine fundus is replaced into the abdominal cavity (unless a concurrent tubal ligation is to be performed). The incision is reinspected for hemostasis, and the bladder flap also is inspected. The paracolic gutters are visualized, and any blood clots are removed with dry laparotomy sponges. The vesicouterine peritoneum and parietal peritoneum can be reapproximated with a running chromic stitch. Many physicians prefer to not close the peritoneum because these surfaces reapproximate within 24-48 hours and can heal without scar formation. Furthermore, the rectus muscles to do not need to be reapproximated.

The subfascial tissue is inspected for bleeding, and, if hemostatic, the fascia is closed. The fascia can be closed with a running stitch, and synthetic braided sutures are preferred over chromic sutures. Chromic sutures do not maintain their tensile strength as long or as predictably as synthetic braided material. If the patient is at risk for poor wound healing (eg, those with chronic steroid use), then a delayed absorbable or permanent suture can be used. Place stitches at approximately 1-cm intervals and more than 1 cm away from the incision line.

The subcutaneous tissue should be inspected for hemostasis and can be irrigated according to physician preference. The subcutaneous tissue does not have to be reapproximated, but in patients who are obese (subcutaneous depth >2 cm), a drain may be placed and connected to an external bulb suction apparatus. The skin edges can be closed either with a subcuticular stitch or with staples (removed 3 or 4 d postoperatively).

Postoperative details: In the recovery room, vital signs are taken every 15 minutes for the first 1-2 hours, and urine output is monitored on an hourly basis. In addition to routine assessment, palpate the fundus to ensure that it feels firm. Attention needs to be paid to the amount of vaginal bleeding.

If the patient had regional anesthesia, they usually receive a long-acting analgesic with the regional anesthetic. Therefore, pain control usually is not an issue in the first 24 hours. If a patient did not receive a long-acting analgesic or had general anesthesia, narcotics can be administered either intramuscularly or intravenously (on schedule or with a basal rate supplemented with patient-controlled boluses). When the patient is tolerating liquids, narcotics can be administered orally as needed.

When patients recover sensation after a regional anesthetic and vital signs have been stable with minimal vaginal bleeding, they can be taken to their room. The patient should have vital signs taken every hour for at least the first 4 hours and, again, attention should be paid to urine output.

Overall, a patient should receive approximately 3-4 L of intravenous fluid from initiation of the intravenous line through the first 24 hours. The patient can be started on clear liquids 12-24 hours after an uncomplicated procedure, and diet can be advanced accordingly. When the patient is able to tolerate good oral intake, the intravenous fluids can be stopped.

The bladder catheter can be removed 12-24 hours postoperatively. If the patient is unable to void in 6 hours, consider replacing the Foley for an additional 12-24 hours.

On the first postoperative day, encourage the patient to ambulate. Increase ambulation every day as tolerated by the patient. The dressing can be removed 12-24 hours after surgery and can be left open after that time. Typically, the blood count is checked 12-24 hours after surgery, or sooner if a greater than average blood loss has occurred.

If a patient plans to breastfeed, this can be initiated within a few hours after delivery. If a patient plans to bottle feed, a tight bra or breast binder should be used in the postoperative period.

If the patient has recovered well postoperatively, she can be discharged safely 3-4 days after surgery. If staples were used to approximate the skin, remove them prior to discharge. If the patient has had a vertical skin incision or is at risk for poor healing (eg, diabetes or long-term steroid use), the physician may elect to keep the staples in for 2-3 extra days and have the patient return to the office at that time.

Prior to discharge, a discussion about contraception should take place. Stress that even if a mother is breastfeeding, she still can conceive. Ask patients to refrain from intercourse for 4-6 weeks postpartum.

Follow-up care: After a cesarean delivery, the patient can be observed as a patient who delivered vaginally. The normal recommendation is to have the patient make a follow-up appointment 4-6 weeks after delivery. If bleeding has stopped, a repeat Papanicolaou test is customary. During this visit, review any notable findings from the surgery and discuss delivery options for future pregnancies.

COMPLICATIONS

Compared to a vaginal delivery, maternal mortality and especially morbidity is increased with cesarean delivery. The overall maternal mortality rate is 6-22 deaths per 100,000 live births, with approximately one third to one half of maternal deaths after cesarean delivery being directly attributable to the operative procedure itself. Part of this increase in mortality is that associated with a surgical procedure and, in part, related to the conditions that may have led to needing to perform a cesarean delivery.

Major sources of morbidity and mortality can be related to sequelae of infection, thromboembolic disease, anesthetic complications, and surgical injury.

Intraoperative complications

• Uterine lacerations: Uterine lacerations, especially of the lower uterine segment, are more common with a transverse uterine incision. These lacerations can extend laterally or inferiorly. They are repaired easily. Take care to identify the uterine vessels when repairing lateral extensions, and, when repairing inferior extensions, the surgeon needs to think about the ureters. If the laceration extends into the broad ligament, strongly consider opening the broad ligament and identifying the course of the ureters.

  　

• Bladder injury: This is an infrequent complication. It is more common with transverse abdominal incisions and in repeat cesarean deliveries. The bladder most commonly is injured when entering the peritoneal cavity or when separating the bladder from the lower uterine segment. Bladder injury has been reported to occur in more than 10% of uterine ruptures and in approximately 4% of cesarean hysterectomies. If a possibility exists that a cesarean hysterectomy may be performed, mobilize the bladder inferiorly as well as possible when dissecting it free of the lower uterine segment. If the dome of the bladder is lacerated, it can be repaired simply with a 2-layer closure of 2-0 or 3-0 chromic sutures, with the Foley catheter left in place for a few extra days. If the bladder is injured in the region of the trigone, consider ureteral catheterization with possible assistance from a urologist.

  　

• Ureteral injury: Injury to the ureter occurs in up to 0.1% of all cesarean deliveries and up to 0.5% of cesarean hysterectomies. It is most likely to occur when repairing extensive lacerations of the uterus. Ureteral injury, most commonly occlusion or transection, usually is not recognized during the time of the operation.

  　

• Bowel injury: Bowel injuries occur in less than 0.1% of all cesarean deliveries. The most common risk factor for bowel injury at the time of cesarean delivery is adhesions from prior cesarean deliveries or prior bowel surgery. If the bowel is adherent to the lower portion of the uterus, dissect it sharply. Injuries to the serosa can be repaired with interrupted silk sutures. If the injury is into the lumen, perform a 2-layer closure. The mucosa can be closed with interrupted 3-0 absorbable sutures placed in a transverse fashion for a longitudinal injury. For multiple injuries and injury to the large intestine, consider intraoperative consultation with a general surgeon or gynecologic oncologist.

  　

• Uterine atony: Another intraoperative complication that can be encountered in a patient with a multiple gestation, polyhydramnios, or a failed attempt at a vaginal delivery in which the patient was on Pitocin augmentation for a prolonged period is uterine atony. When the uterus is closed, attention must be paid to its overall tone.

Postoperative complications

• Postpartum endomyometritis: This is increased significantly in patients who have had a cesarean delivery. The rate of endomyometritis is up to 20-fold higher than with a vaginal delivery, with a reported mean of 35-40% occurrence after a cesarean delivery. Major risk factors include whether the cesarean delivery was the intended (primary) procedure and the socioeconomic status of the patient. Other major risk factors include duration of membrane rupture, duration of labor, number of pelvic examinations, length of time with internal fetal monitors in place, and the presence of chorioamnionitis prior to initiating cesarean delivery. Blood cultures are positive in approximately 10% of patients with postoperative febrile morbidity, and broad-spectrum antibiotics should be used. The postcesarean rate of endomyometritis can be decreased to approximately 5% with the use prophylactic antibiotics.

  　

• Wound infection: Following a cesarean delivery, the risk of a wound infection ranges from 2.5% to higher than 15%. Risk factors are similar to those noted for endomyometritis, with the lowest risk associated with those having a planned cesarean delivery. If chorioamnionitis is present at the time of the procedure, the risk for a wound infection can be as high as 20%. If a wound infection is suspected, open, irrigate, and debride the incision. Then, the open wound can be packed and cleaned several times a day. The wound can be allowed to heal by secondary intention, or, when it has begun to granulate, it can be closed.

  　

• Fascial dehiscence: An infrequent but emergent complication of a wound breakdown is a fascial dehiscence. It occurs in approximately 5% of patients with a wound infection and is suggested when excessive discharge from the wound is present. If a fascial dehiscence is observed, the patient should be taken immediately to the operating room where the wound can be opened, debrided, and reclosed in a sterile environment.

  　

• Urinary tract infections: The second most common etiology for postcesarean febrile morbidity is urinary tract infections. The incidence ranges from 2-16%, and the process of placing an indwelling catheter for the surgery is a risk factor in itself. The incidence of urinary tract infections is increased in patients with diabetes, those who have other comorbidity, and those who have a longer duration of use of the indwelling catheter.

  　

• Bowel function: Postoperatively, some patients may experience a slow return of bowel function. Postoperative narcotics may delay return of normal bowel function in a few patients. Most respond to conservative therapy, but a small portion may require decompression. In those with a slow return of bowel function, assessment of fluid and electrolyte status needs to be a priority.

  　

• Thromboembolic complications: These also are increased in the patient who has undergone a cesarean delivery. Approximately 1 in 400 pregnant patients experience a deep venous thrombosis. The risk for developing a thrombus is increased 3- to 5-fold with a cesarean delivery. Other risks include obesity, advanced maternal age, higher parity, and poor postoperative ambulation. In those with risk factors, consider pneumatic compression stockings. If a deep venous thrombosis is not treated, up to one quarter of patients will develop pulmonary emboli and 15% of these could be fatal. A deep venous thrombosis sometimes is difficult to diagnose, and the first sign may be associated with a pulmonary embolus.

  　

• Pelvic thrombophlebitis: Another infection-related complication of a cesarean delivery is septic pelvic thrombophlebitis. As many as 2% of patients with an endomyometritis or wound infection can develop this complication, and it is largely a diagnosis of exclusion. Suspect this diagnosis if a patient fails to respond to broad-spectrum antibiotics. Physical examination may detect a tender cordlike mass lateral to the uterus. Ultrasound, pelvic CT scan, or MRI may aid in the diagnosis. Place patients on therapeutic heparin along with continuing broad-spectrum antibiotics. The length of adequate treatment once a patient has defervesced is subject to debate (anywhere from 48-h afebrile to a total of 7-10 d of treatment). After completing the desired treatment course, patients do not need to be anticoagulated further.

OUTCOME AND PROGNOSIS

Patients who undergo cesarean delivery usually take slightly longer to fully recover than those who have a vaginal delivery. However, the overall long-term condition of the patient is not adversely affected. Occasionally, some patients can experience pelvic pain associated with intra-abdominal adhesions, a situation that can be aggravated in those who have multiple procedures.

The most important things for patients to know about their cesarean delivery are why they had one and what kind of incision was performed on the uterus.

If a patient had a cesarean delivery for presumed cephalopelvic disproportion, then attempting a vaginal birth with the next pregnancy is associated with a decreased risk of success. Overall, patients attempting a vaginal birth after a prior cesarean delivery can expect success approximately 70% of the time. If the cesarean delivery was performed because of an abnormal fetal heart pattern or for a malpresentation, then expectations for a successful vaginal birth can be higher than 70%. If the uterine incision was vertical, the risk of uterine rupture is increased above the approximate 1% risk associated with a low transverse incision. If the incision was confined to the lower segment, many physicians allow patients to attempt a vaginal birth in subsequent pregnancies. However, if the incision extended into the upper contractile portion, the risk of uterine rupture can approach 10%, with 50% of these occurring prior to the onset of labor.

A previous cesarean delivery can increase the risk of developing placenta accreta if placenta previa is present in any subsequent pregnancies. The risk of placenta accreta in a patient with previa is approximately 4% with no prior cesarean deliveries; the risk increases to approximately 25% with 1 prior cesarean delivery and to 40% with 2 prior cesarean deliveries.

FUTURE AND CONTROVERSIES

Further investigation continues to evaluate which patients should undergo a trial of labor after having a cesarean delivery.

Information about whether a cesarean delivery should be performed for all term breech presentations is currently being collected and will be published soon.

Urogynecologists are suggesting that all women should consider outright cesarean delivery to prevent pelvic floor dysfunction. This is an extremely controversial area that will receive more attention in the next few years.