INTRODUCTION — As with most surgical procedures, there is no standard technique for cesarean birth. The following discussion will review each step in the procedure and provide evidence-based recommendations for surgical technique, when these data are available. In many cases, small absolute differences in outcome among surgical techniques are not clinically important; in these settings, time and cost savings assume greater importance [1].

Other aspects of cesarean birth are reviewed separately:

●(See "Cesarean birth: Preoperative planning and patient preparation".)

●(See "Anesthesia for cesarean delivery".)

●(See "Cesarean birth: Postoperative issues".)

●(See "Repeat cesarean birth".)

●(See "Cesarean birth on maternal request".)

The Enhanced Recovery After Surgery (ERAS) Society has published guidelines for perioperative care of patients undergoing cesarean birth, the ERAS Cesarean Delivery Guidelines, which cover the time from decision to operate (starting with the 30 to 60 minutes before skin incision) to hospital discharge [2-4]. The American College of Obstetricians and Gynecologists has published a guideline for enhanced recovery after surgery [5]. Other organizations and many hospitals have also created such guidelines/pathways [6].

OPENING THE ABDOMEN — The advantages and disadvantages of various incisions and the procedure for opening the abdomen from skin to peritoneum are generally the same as for any open abdominal surgery. (See "Incisions for open abdominal surgery".)

Skin incision

Choice of incision — For most patients, we prefer a transverse skin incision since it is associated with a better cosmetic appearance and possibly less postoperative pain and hernia formation than the vertical midline skin incision [7-9]. Although we rarely perform a vertical midline incision, we often select this approach when:

●The incision-to-delivery time is critical

●A transverse incision may not provide adequate exposure

●The patient has a bleeding diathesis and thus is at increased risk of subcutaneous or subfascial hematoma formation

Transverse incisions — Two common transverse incisions for cesarean birth are the Pfannenstiel type and the Joel-Cohen type incisions (eg, Misgav Ladach) (figure 1).

●The Pfannenstiel skin incision is slightly curved, 2 to 3 cm above the symphysis pubis, with the midportion of the incision within the clipped area of the pubic hair.

●The Joel-Cohen type incision is straight, 3 cm below the line that joins the anterior superior iliac spines, and slightly more cephalad than Pfannenstiel [10].

In meta-analyses of randomized trials of surgical incisions for cesarean birth, the Joel-Cohen type incision had significant short-term advantages compared with the Pfannenstiel incision, including lower rates of fever, postoperative pain, and use of analgesia; less blood loss; and shorter operating time (overall and incision-to-delivery) and hospital stay [11-13]. In two trials (411 women) comparing the incisions, the Joel-Cohen incision resulted in a 65 percent reduction in postoperative febrile morbidity (relative risk [RR] 0.35, 95% CI 0.14-0.87) and a 45 percent reduction in postoperative analgesic requirements (RR 0.55, 95% CI 0.40-0.76), as well as shorter incision to delivery time (mean difference [MD] -1.90, 95% CI -2.53 to -1.27 minutes), shorter operating time (MD -11.40, 95% CI -16.55 to -6.25 minutes), lower estimated blood loss (MD -58.00, 95% CI -108.51 to -7.49 mL), lower total dose of analgesia in the first 24 hours (MD -0.89, 95% CI -1.19 to -0.59), and shorter postoperative maternal hospital stay (MD -1.50, 95% CI -2.16 to -0.84 days) [11]. However, many surgeons continue to prefer the Pfannenstiel incision, in part because it is somewhat lower on the abdomen and therefore has a less negative cosmetic appearance.

In severely obese women, a supraumbilical incision may be preferable to a suprapubic incision. (See "Cesarean birth: Patients with obesity", section on 'Abdominal wall incision'.)

Vertical incision — Compared with transverse incisions, a vertical midline incision generally allows faster abdominal entry, causes less bleeding and superficial nerve injury, and can be easily extended cephalad if more space is required for access. In a prospective cohort study including over 3500 emergency cesarean births, that median incision to delivery interval was faster for vertical than transverse skin incisions (three versus four minutes for primary cesareans and three versus five minutes for repeat cesareans), but neonatal outcomes were not improved, and some maternal and neonatal outcomes were worse in the vertical incision group (eg, need for postpartum maternal transfusion [8.5 versus 5.3 percent], neonatal intubation in the delivery room [17 versus 13 percent]) [14]. The poorer outcomes were attributed to unidentified confounders since the choice of skin incision is not independent of the indication for cesarean birth.

In severely obese women, a supraumbilical incision may be preferable to a subumbilical incision. (See "Cesarean birth: Patients with obesity", section on 'Abdominal wall incision'.)

Scalpel or electrocautery? — The author prefers incising with a scalpel rather than an electrocautery device, but there is no clear evidence of superiority in short- or long-term outcomes between the two, and so the surgeon's preference is reasonable. The body of evidence from randomized trials in general surgery patients [15-17] and a small trial in women undergoing repeat cesarean [18] shows that neither scalpel nor electrosurgery holds a clinically significant benefit over the other for skin incision; either approach or a mixture of the two approaches is acceptable. (See "Incisions for open abdominal surgery", section on 'Skin incision'.)

It is not necessary to change to a fresh scalpel blade after opening the abdomen, given that the rate of wound infection appears to be similar with a one-scalpel versus two-scalpel technique [19].

Subcutaneous tissue layer — There are no randomized trials comparing techniques for incision and dissection of the subcutaneous tissues at cesarean birth. We prefer blunt dissection (with fingers) over sharp dissection (with the knife), as blunt dissection has been associated with shorter operative times, less chance of injury to vessels, and less postoperative pain [20,21]. The tissue is opened from medial to lateral.

Fascial layer — A small transverse incision is usually made medially with the scalpel and then extended laterally with scissors. Alternatively, the fascial incision can be extended bluntly by inserting the fingers of each hand under the fascia and then pulling in a cephalad-caudad direction, which is part of the Joel-Cohen/Misgav-Ladach technique [10,20] (see 'Alternative techniques' below). A randomized trial of sharp versus blunt fascial incision using each patient as her own control (sharp dissection for half the incision and blunt dissection for the other half) found no difference in postoperative pain scores but was too small (28 patients) to detect modest differences [22].

Rectus muscle layer — Rectus muscles can be separated bluntly in most cases. Transection of the muscles (ie, Maylard technique) is avoided, if possible, as leaving the muscles intact preserves muscle strength in the early postoperative months; otherwise, there are no clear differences in outcome between the two techniques [23-25].

Dissection of the rectus fascia from the rectus muscles appears to be unnecessary, although commonly performed [20,21,26]. In one small randomized trial, non-dissection resulted in higher postoperative hemoglobin levels and less pain [27].

Opening the peritoneum — We favor using fingers to bluntly open the peritoneum to minimize the risk of inadvertent injury to bowel, bladder, or other organs that may be adherent to the underlying surface, as in the Joel-Cohen type approach [20,21,26]. However, a sharp technique is also acceptable. In a large randomized trial (CORONIS) that examined five elements of the cesarean birth technique in intervention pairs, there was no significant difference between blunt and sharp technique for the primary composite outcome of maternal death, infectious morbidity, further operative procedures, or blood transfusion >1 unit [28,29].

An extraperitoneal approach is another option. Most obstetricians are not familiar with this technique since it was used primarily in the pre-antibiotic era to decrease the risk of intraperitoneal infection. It requires a detailed knowledge of the relationship between the fascial planes and the bladder and lower uterine segment. Theoretically, avoiding exposure of the peritoneal cavity to blood, amniotic fluid, vernix, and mechanical irritation can potentially reduce nausea and vomiting, postoperative pain, voiding disturbances, and other side effects and complications of cesarean birth. This hypothesis is supported by a small randomized trial that compared the transperitoneal and extraperitoneal techniques and found the latter resulted in less intraoperative nausea and vomiting and less postoperative pain [30].

A Maylard incision or an extraperitoneal approach may be useful in patients with dense adhesions between the lower uterine segment and the peritoneum but is very rarely needed.

Avoiding visceral injury in patients with dense intraperitoneal adhesions — If there are dense adhesions between the anterior abdominal wall and the anterior surface of the uterus, we enter the peritoneum bluntly and as close as possible to the upper abdomen to avoid these areas. Sharp dissection also may be needed and should be performed cautiously by making shallow incisions under direct vision. Other approaches are to start laterally or use a paravesical or supravesical extraperitoneal approach to avoid dense midline adhesions [31].

A surgeon experienced in complex abdominal surgery should assist if meticulous dissection of dense adhesions involving important structures is needed. Insertion of ureteral stents can be useful to facilitate intraoperative identification (and avoidance) of the ureters, but is rarely indicated for cesarean birth. (See "Urinary tract injury in gynecologic surgery: Epidemiology and prevention", section on 'Prophylactic ureteral catheters'.)

If pelvic adhesions require extensive dissection with risk of injury to the bowel, urinary tract, or major blood vessels to expose the lower uterine segment, and the patient desires tubal ligation, we avoid or minimize adhesiolysis and perform the hysterotomy in the most appropriate accessible location. A case report in which the entire length of the ventral aspect of the uterus and bladder was densely adherent to the rectus sheath described extending a vertical incision in the abdominal wall above the level of the adhesions and then entering the uterine cavity through an incision across the fundus [32].

Ensuring adequate exposure — The full thickness abdominal wall incision should be adequate to allow easy delivery of the fetus. While there are no trials on this technical aspect of cesarean birth, a 15 cm incision (the size of a standard Allis clamp) is probably the minimal length that allows atraumatic and expeditious delivery of the term fetus [10] The surgeon and an assistant together can manually stretch apart the opening at the angles of the incisions if needed, but additional sharp dissection may be necessary.

INTRAABDOMINAL PROCEDURES

Bladder flap — We do not routinely create a bladder flap. In a meta-analysis of four trials that randomly assigned women to undergo or not undergo development of a bladder flap at cesarean birth, omitting this procedure did not increase short-term adverse outcomes (bladder injury, blood loss, duration of hospitalization) and reduced the incision-to-delivery interval by 1.3 minutes [33]. The trials excluded very preterm and emergency deliveries. These data are inadequate to definitively assess uncommon morbidities, such as bladder injury, or the long-term consequences of not creating a bladder flap, such as long-term bladder function.

A subsequent randomized trial found that urinary symptom scores at 6 to 8 weeks postpartum were similar whether or not a bladder flap was performed, but women who received a bladder flap had more bothersome urinary symptoms [34].

Some obstetricians choose to selectively perform a bladder flap if a difficult delivery is anticipated, such as when the fetal head is deep in the pelvis or when the bladder is attached well above the lower uterine segment after a previous cesarean birth. In these cases, creation of the bladder flap may help to keep the bladder dome out of the surgical field if the uterine incision extends. In some patients, such as those who are not in labor, it may not be possible to make an incision in the lower uterine segment without first creating a bladder flap.

The location of the bladder is best delineated by palpating the bladder catheter, if present. The demarcation between the lower and upper uterine segments is difficult to determine clinically, sonographically, or histologically. The location or level of the demarcation also changes based on the clinical situation.

Hysterotomy

Choice of incision — The uterine incision is usually transverse but may be vertical; no randomized trials have compared the two techniques. The principal consideration is that the incision must be large enough to allow atraumatic delivery of the fetus. Factors to consider include the position and size of the fetus, location of the placenta, presence of leiomyomas, development of the lower uterine segment, and future pregnancy plans. Small comparative studies of transverse and vertical incisions have not reported a difference in incision to delivery time or short-term maternal and infant outcomes between the two techniques [35,36]. However, if the woman has a subsequent pregnancy, she may be at higher risk of uterine rupture if she has a low vertical incision and chooses to undergo a trial of labor.

Prior to making a hysterotomy incision, the surgeon should be aware of the general location of the placenta and the fetal lie. This information helps in avoiding laceration of the placenta and in delivery of the fetus. If labor has been prolonged and the head is deep in the pelvis, the lower uterine segment may be very thin and retracted superiorly. In these cases, it is important to avoid making the incision too inferiorly as it may transect the cervix or vagina. Accidental laparoelytrotomy (ie, delivery of the fetus through a vaginal incision) can be avoided by remembering that the uterovesical fold is usually at the upper margin of the lower segment; thus, the uterine incision should be made just above, or at a maximum a centimeter below, this anatomic landmark [37-39].

Transverse incision — For most cesarean births, we recommend making a transverse incision along the lower uterine segment (ie, Monro Kerr or Kerr incision). Compared with vertical incisions, advantages of the transverse incision include less blood loss, less need for bladder dissection, easier reapproximation, and a lower risk of rupture in subsequent pregnancies [10]. It is the best incision for women who are planning another pregnancy and may attempt a trial of labor in that pregnancy. (See "Choosing the route of delivery after cesarean birth", section on 'One prior low transverse uterine incision' and "Choosing the route of delivery after cesarean birth", section on 'Prior low vertical uterine incision'.)

The major disadvantage of the transverse incision is that significant lateral extension is not possible without risking laceration of major blood vessels. A "J" or inverted "T" extension is often required if a larger incision is needed. This can be problematic because the "J" extension goes into the lateral fundus and the angles of the inverted "T" incision are poorly vascularized. Both the J and T incisions potentially result in a weaker uterine scar, which is a concern if the patient has a subsequent pregnancy.

Low vertical and classical incisions — There are two types of vertical incisions: the low vertical (Kronig, DeLee, or Cornell) and the classical vertical. The low vertical is performed in the lower uterine segment and appears to be as strong as the low transverse incision [40]. The major disadvantage of the low vertical incision is the possibility of extension cephalad into the uterine fundus or caudally into the bladder, cervix, or vagina. It is also difficult to determine whether the low vertical incision is truly low, as the separation between lower and upper uterine segments is not easily identifiable.

A vertical incision that extends into the upper uterine segment/fundus is termed a classical incision. This incision is rarely performed at or near term because in subsequent pregnancies it is associated with a higher frequency of uterine dehiscence/rupture (4 to 9 percent) compared with low vertical (1 to 7 percent) and low transverse (0.2 to 1.5 percent) incisions; it is also associated with more maternal morbidity [41,42]. (See "Uterine rupture: After previous cesarean birth".)

Whether a vertical incision is confined to the lower, noncontractile portion of the myometrium (low vertical) or extends into the upper contractile portion of the myometrium (classical) is a subjective assessment; no objective method for differentiating between the two types of uterine incisions is available. However, if the incision extends to the level or near the level of the round ligament insertion, it should definitively be considered classical.

The generally accepted indications for considering a vertical uterine incision are:

●Poorly developed lower uterine segment when more than normal intrauterine manipulation is anticipated (eg, extremely preterm breech presentation, back down transverse lie).

●Lower uterine segment pathology that precludes a transverse incision (eg, large leiomyoma, anterior placenta previa or accreta).

●Densely adherent bladder.

●Postmortem delivery.

●Delivery of a very large fetus (eg, anomalous, extreme macrosomia) when there is high risk of extension of a transverse incision into uterine vessels or a T or J extension may be required to extract the fetus.

Procedure — Hysterotomy is begun by making a small incision with a scalpel. Various techniques are used to minimize the risk of fetal injury while making this incision. All involve elevating and carefully thinning the inner myometrial and decidual layers to minimize bleeding, maximize exposure, and promote separation of the uterine tissue from the fetal membranes or skin.

After the initial incision on the uterus has been made with the scalpel, and most of the uterine wall has been cut, we prefer to enter the uterine cavity with the index finger of the dominant hand of the surgeon, in a blunt fashion. This is effective >90 percent of the time in our experience, reduces blood loss, and avoids any risks of fetal injury with a sharp instrument. If this is not easily accomplishable, the next steps may be helpful:

●Consider applying Allis clamps to the superior and inferior edges of the myometrial incision and elevate them, as needed.

●Remove the suction tip and directly apply the end of the suction tubing to the center of the myometrial incision to balloon out and thin out this layer while providing easily identifiable, relatively blood-free exposure. If possible, leave the membranes intact until complete extension of the incision.

Expanding the incision — After the uterine cavity is entered, the hysterotomy incision is extended using blunt expansion with the surgeon's fingers or bandage scissors. We recommend blunt expansion because it is fast and has less risk of inadvertent trauma to the fetus.

Cephalad-caudad blunt expansion has maternal benefits compared with transverse blunt expansion. In a meta-analysis of randomized trials, pulling cephalocaudally with the index fingers to extend the uterine incision transversely reduced the risk of unintended incision extension (RR 0.62, 95% CI 0.45–0.86) and uterine vessel injury (RR 0.55; 95% CI 0.41–0.73) [43].

Uterine stapler — We do not use the auto stapler. A meta-analysis of two small randomized trials did not show any benefits over conventional sharp dissection [44]. This technique should be reserved, if used at all, for rare indications (eg, ex utero intrapartum treatment [EXIT] procedure).

Fetal extraction — The fetus should be extracted expeditiously and nontraumatically. Most studies, but not all [45,46], have reported a direct association between a prolonged uterine incision-to-delivery time and lower fetal blood gas pH values and Apgar scores, regardless of type of anesthesia [47]. The mechanism is thought to be hysterotomy-induced increased uterine tone, which can interfere with uteroplacental blood flow.

Extraction of the fetus at cesarean is usually uncomplicated. For fetuses in cephalic presentation, the key points are placing the obstetrician's fingers around the curvature of the head for leverage, lifting without overly flexing the wrist, and not using the lower uterine segment as a fulcrum, which can lead to extensions of the hysterotomy incision, if done improperly. The obstetrician usually inserts the dominant hand through the hysterotomy incision and around the top of the fetal head. Standing on a stool may be helpful. Using the fingers and palm, the head is gently elevated and flexed to bring the occiput into the open hysterotomy, and then guided through the incision, aided by modest transabdominal fundal pressure from the other hand or an assistant, as needed (figure 2). The shoulders are then delivered using gentle traction to guide one, and then the other, through the hysterotomy, using fundal pressure as needed; the rest of the body should follow easily.

Extreme prematurity, a deeply impacted or floating fetal head, or an abnormal lie can make fetal extraction difficult. The approach to difficult fetal extraction is reviewed separately. (See "Cesarean birth: Management of deeply engaged, impacted and floating fetal presentations".)

Cord clamping — We delay cord clamping for at least 30 to 60 seconds in infants who do not require resuscitation. Ideally the cord clamp is applied following onset of respiration. Delayed, rather than immediate, cord clamping of vigorous newborns results in higher neonatal hemoglobin levels and iron stores and facilitates the fetal to neonatal transition. It appears to be particularly beneficial for preterm newborns, but is recommended for term newborns as well. The major disadvantage is an increased need for phototherapy for jaundice. (See "Management of normal labor and delivery", section on 'Early versus delayed cord clamping'.)

Care of the newborn — An appropriately trained clinician should be present to care for the newborn [48]. The degree of training depends on the risk for neonatal complications. (See "Overview of the routine management of the healthy newborn infant".)

Early skin to skin contact between mother and newborn appears to promote breastfeeding and may help with physiological stabilization [49].

Placental extraction — We do not drain any residual blood in the placenta and cord before extraction. There is only limited evidence that it is beneficial: In a small trial, draining the placenta passively or actively prior to extraction resulted in less fetomaternal transfusion [50]. However, the clinical significance of this finding (ie, frequency of alloimmunization) was not evaluated.

We suggest gentle traction on the cord and use of oxytocin to enhance uterine contractile expulsive efforts and allow spontaneous placental expulsion, rather than manual extraction. In a systematic review of randomized trials, manual extraction resulted in a higher rate of postoperative endometritis (RR 1.64, 95% CI 1.42-1.90), greater blood loss (weighted mean difference 94 mL, 95% CI 17-172 mL), a higher rate of blood loss over 1000 mL (RR 1.81, 95% CI 1.11-2.28), and lower postpartum hematocrit [51]. It is hypothesized that spontaneous expulsion allows the uterus time to contract and thus close myometrial sinuses. It also avoids potential contamination of open sinuses from any bacteria on the surgeon's gloves, although this does not appear to be clinically significant since changing gloves before manual removal of the placenta does not reduce the risk of endometritis [52].

Changing gloves after delivery of the placenta may be considered, based on its association with a decrease in wound infections in some studies. In a meta-analysis of randomized trials, changing gloves after placental delivery reduced wound infections by 60 percent (20 of 332 [6 percent] versus 55 of 346 [16 percent]; RR 0.39, 95% CI 0.24-0.63) [53]. However, the intervention did not reduce the frequency of postpartum endometritis or febrile morbidity and there were many limitations to the included trials (eg, lack of adequate methodologic information, lack of blinding where possible, lack of information about intention-to-treat and loss to follow up, unclear matching for risk factors such as prelabor rupture of membranes, active labor versus prelabor cesarean, and cervical dilation). High-quality, adequately powered randomized trials using a consistent validated definition of surgical site infection are needed before making a definitive conclusion regarding the effectiveness of changing gloves to reduce postpartum infection after cesarean.

To ensure that the entire placenta has been removed, the inside of the uterus is usually wiped with a gauge sponge to remove any remaining membranes or placental tissue. This maneuver may also stimulate uterine contraction.

PREVENTION OF POSTPARTUM HEMORRHAGE — Uterine contraction is the main mechanism for reduction of uterine bleeding. Oxytocin is administered intravenously after delivery of the infant to promote uterine contraction and involution [1]. The author also administers misoprostol or methylergometrine. (See "Management of the third stage of labor: Prophylactic drug therapy to minimize hemorrhage", section on 'Active management' and "Anesthesia for cesarean delivery", section on 'Administration of uterotonics'.)

While we and many other clinicians massage the uterus after delivery until it becomes firm to reduce the risk of postpartum hemorrhage, no randomized trials have evaluated the efficacy of massage after cesarean birth [54].

Postpartum hemorrhage is an obstetric emergency. Management is reviewed in detail separately. (See "Postpartum hemorrhage: Management approaches requiring laparotomy".)

UTERINE CLOSURE

Exteriorizing the uterus — We, and many others, generally exteriorize the uterus to improve exposure and facilitate closure of the hysterotomy. Both personal preference and individual clinical circumstances should guide this decision.

●In a meta-analysis of randomized trials (20 trials, >20,000 participants) comparing exteriorization with in situ repair, exteriorization resulted in [55]:

•More patients with intraoperative nausea and vomiting (37.6 percent versus 22.4 percent; odds ratio [OR] 2.09, 95% CI 1.66-2.63)

•No significant difference in perioperative hemoglobin concentration decrease, estimated blood loss, transfusion requirement, postoperative nausea and vomiting, duration of surgery, duration of hospital stay, time to return of bowel function, fever, endometritis, or wound infection.

•Higher postoperative pain scores at six hours (OR 1.64, 95% CI 1.31-2.03) with a trend toward increased need for rescue analgesia (OR 2.48, 95% CI 0.89-6.90), but similar pain scores at 24 hours.

A limitation of the analysis is that the effects of prophylactic interventions to reduce intraoperative nausea and vomiting (eg, prophylactic phenylephrine infusion and antiemetic drugs) and postoperative pain, which are components of contemporary anesthesia practice, could not be evaluated. The effects of the observed adverse outcomes on maternal satisfaction with the childbirth experience and initiation of breastfeeding also could not be evaluated.

Our approach — We usually perform a two-layer, continuous full-thickness closure with delayed absorbable synthetic suture. The first-layer incorporates the myometrium plus the decidual edge to achieve hemostasis and the second imbricating layer covers the exposed myometrial edges. (See 'Choice of suture' below and 'Single- versus double-layer closure of lower uterine segment incisions' below.)

The endometrial layer (decidua) should probably be included in the full thickness myometrial closure. This opinion is based on a randomized trial that assigned 78 term pregnant patients delivered by cesarean to one layer myometrial closure either including or excluding the endometrial layer [56]. The frequency of a wedge-type healing defect (niche) on ultrasound six weeks postpartum was significantly lower in the group that had full thickness suturing (45 versus 69 percent). Outcomes in subsequent pregnancies were not evaluated, so the clinical significance of this finding is unknown. The niche and reduced residual myometrial thickness at its apex have been hypothesized to increase the risk of adverse gynecologic and reproductive outcomes (eg, postmenstrual spotting, dehiscence, dysmenorrhea, rupture).

Use of blunt (rounded tip) needles during closure is associated with similar maternal outcomes as use of sharp (tapered point) needles [57], and is much safer for the surgeon (glove perforation rate RR 0.45, 95% CI 0.37-0.54 [58]). However, blunt-tip needles perform less well surgically than sharp needles.

We do not use locking sutures unless arterial bleeding is evident. No convincing evidence is available to guide choice of technique (eg, continuous [locked or nonlocked] versus interrupted) [44].

Choice of suture — Choice of suture is largely based on personal preference. In a large randomized trial (Caesarean section surgical techniques [CORONIS]), choice of suture material (eg, chromic catgut versus delayed absorbable synthetic [eg, polyglactin 910, poliglecaprone 25]) did not result in statistically significant differences in maternal outcome [28,29].

A 0-delayed absorbable synthetic monofilament (eg, Monocryl) or braided (eg, Vicryl) suture is commonly used in the United States. Barbed suture has been used successfully for knotless closure of myomectomy incisions [59-61] and skin closure of the Pfannenstiel incision during cesarean birth [62]. Use of barbed suture for uterine closure appeared to shorten total surgical time by approximately two minutes and reduce the need for additional hemostatic sutures (RR 0.39, 95% CI 0.28-0.54) in a meta-analysis of three small trials, but the level of evidence was low to very low [63].

Sutures coated with antimicrobial compounds may decrease the rates of surgical site infection, but randomized trials have reported discordant results [64], none have been performed in patients undergoing cesarean birth, and the development of surgical site infection is multifactorial so manipulation of a single factor (eg, suture) is not likely to provide a significant benefit for all patients. (See "Principles of abdominal wall closure", section on 'Triclosan-coated versus noncoated sutures'.)

Single- versus double-layer closure of lower uterine segment incisions — As discussed above, we generally perform a two-layer rather than a single-layer uterine closure, but use a single-layer closure when a tubal ligation is performed concurrently since it saves time and concern about uterine rupture in a subsequent pregnancy is not an issue. Given the available data (see below), either a one- or two-layer closure technique is within acceptable standards of medical practice. If a single-layer closure is performed to save time, we suggest an unlocked technique [65-68]. A double (or even triple)-layer closure may be necessary when the myometrium is thick, such as with a classical and some low vertical incisions.

Short-term maternal outcomes are similar for single- and double-layer closure, except a single-layer closure takes less time. In a 2014 systematic review and meta-analysis of comparative studies, single- and double-layer hysterotomy closure resulted in similar rates of overall maternal infectious morbidity, endometritis, wound infection, and blood transfusion, but operative time was six minutes shorter with the single-layer closure (20 studies including almost 15,000 patients) [69].

Over the long term, however, uterine rupture in the next pregnancy is a potential risk of single-layer closure. In a 2017 systematic review and meta-analysis of nine randomized trials (3969 pregnancies), single- and double-layer uterine incision closure resulted in a similar incidence of cesarean scar defects (25 and 43 percent, respectively; RR 0.77, 95% CI 0.36-1.64), uterine dehiscence (0.4 and 0.2 percent, respectively; RR 1.34, 95% CI 0.24-4.82), and rupture in a subsequent pregnancy (0.1 percent for both; RR 0.52, 95% CI 0.05-5.53), but single-layer closure resulted in thinner residual myometrial thickness on postpartum ultrasound (mean difference -2.19 mm, 95% CI -2.80 to -1.57) [70]. Available data were of low quality due to imprecision and indirectness and thus do not provide convincing evidence of safety or harm.

The technique used for the single-layer closure may be a contributing factor. Compared with an unlocked closure, locked closure has been associated with higher occurrence of surrogate markers of scar weakness (thinner myometrial thickness, bell-shaped uterine wall defects) [65,66,71] and dehiscence/rupture [67]. As discussed above, inclusion of the decidua/endometrium (full thickness suturing technique) may be another factor that impacts scar strength [56,71]. However, available data are limited by heterogeneity in criteria for diagnosis of uterine scar defects, length of follow-up, method of follow-up, and closure technique, as well as lack of randomization for the primary outcome and the low number of uterine ruptures.

There is also a paucity of data on other long-term outcomes. A secondary analysis of data from a prospective study of women undergoing repeat cesarean birth observed an increased risk of bladder adhesions in women who had undergone single-layer closure [72]. Further study of possible adverse consequences of single-layer closure is warranted.

Closure of a classical incision — No trials have compared techniques for closure of the thick myometrium of the fundus. We use continuous sutures to close the inner myometrial layer; others prefer interrupted sutures, including interrupted vertical figure of eight sutures. It is useful to have an assistant manually reapproximate the incision by pushing the myometrium on each side toward the midline as each suture is placed and tied. This reduces tension on the incision and helps prevent the suture from tearing through the myometrium, especially when closing the first layer. The mid-portion of the thick myometrial layer is closed with a second line of sutures, leaving approximately 1 cm of outer myometrium still open. We then close the serosa and outer layer using a baseball stitch, which is hemostatic and minimizes exposed raw surfaces, and thus may reduce adhesions (figure 3). The baseball stitch is a continuous, unlocked stitch in which the needle is driven through the cut edge of the myometrium to exit the serosa a few millimeters from the incision for each needle bite. This brings the serosal surfaces together to cover the infolded edges of the incision.

Unnecessary procedures

Cervical dilation — Routine manual/instrumental cervical dilatation before closing the uterus is unnecessary in both laboring and nonlaboring women. Meta-analysis of randomized trials has not found that this practice reduces postoperative morbidity [73].

Uterine irrigation — We do not irrigate the uterus before closure. For prevention of postoperative infection, there is no strong evidence that uterine irrigation with an antibiotic solution is more effective or advantageous compared with preincision parenteral antibiotic prophylaxis [74].

POSTPARTUM CONTRACEPTION — For patients who desire an intrauterine device (IUD) for contraception, the IUD can be placed before or after closure of the hysterotomy. The procedure and potential complications are described separately. (See "Postpartum contraception: Counseling and methods", section on 'Intrauterine devices' and "Intrauterine contraception: Insertion and removal", section on 'Immediate post-placental insertion'.)

The procedure for permanent contraception is also described separately. (See "Overview of female permanent contraception" and "Postpartum permanent contraception: Procedures", section on 'Following cesarean birth'.)

ABDOMINAL WALL CLOSURE — The abdominal cavity should be inspected before closing the abdomen to ensure that hemostasis has been achieved. Retroperitoneal enlargement or bulging of the broad ligament can be signs of retroperitoneal hemorrhage; the abdomen should not be closed until the possibility of ongoing retroperitoneal bleeding has been excluded.

Fascia — The method of fascial closure is a critical aspect of incisional closure, as the fascial closure provides most of the wound strength during healing. Care should be taken to avoid placing too much tension on the fascia since reapproximation, not strangulation, is the goal. Difficulty with hemostasis is usually not a major issue. Meta-analyses of randomized trials of closure of midline fascial incisions suggest the optimal approach involves use of:

●A continuous (not interrupted) technique [75,76]

●Slowly (not rapidly) absorbable suture [75]

●Mass (not layered) closure [76]

●Suture length to wound length ratio of 4 to 1 [76]

Classically, sutures have been placed approximately 1 cm from the edge of the incision and 1 cm apart, without excessive tension. However, in a large randomized trial including non-cesarean surgeries (pregnant women excluded), a technique of 5 mm tissue bites and 5 mm inter-suture spacing limited to the aponeurosis and using a 2-0 suture on a small needle resulted in fewer incisional hernias at one year than the classic 1 cm by 1 cm technique (13 versus 21 percent [35 of 277 versus 57 of 277]; odds ratio [OR] 0.52, 95% CI 0.31-0.87) [77]. We have not changed our midline closure technique as this approach has not been validated in pregnant women.

The majority of fascial closures after cesarean birth involve a transverse fascial incision and no randomized trials have evaluated the optimum closure technique in this setting. For transverse fascial incisions, a continuous nonlocking closure with slowly absorbable #0 or 1 braided suture (eg, polyglactin 910) is a common approach, but a monofilament (eg, polydioxanone) can also be used [7,78]. A randomized trial of closure techniques for repair of transverse incisions of abdominal fascia in rabbits found that interrupted closure had a greater maximum tensile strength than continuous closure during the first two postoperative weeks, but both repair methods had similar maximum tensile strength at four postoperative weeks [79]. (See "Principles of abdominal wall closure", section on 'Fascia' and "Complications of abdominal surgical incisions", section on 'Prevention'.)

Subcutaneous tissue — Subcutaneous tissue closure appears to benefit women undergoing cesarean birth, but available evidence is low quality [80]. We close the subcutaneous adipose layer with interrupted delayed-absorbable sutures if the layer is ≥2 cm thick [81,82]. In a 2004 meta-analysis of randomized trials, suture closure of the subcutaneous adipose layer at cesarean birth decreased the risk of subsequent wound disruption by one-third in women with subcutaneous tissue depth ≥2 cm, but not in those <2 cm [82]. Closure of the dead space seems to inhibit accumulation of serum and blood, which can lead to a wound seroma or hematoma and subsequent wound breakdown [82,83]. This occurrence is a major cause of morbidity, can be costly, and lengthens recovery time. Although placing suture material in the subcutaneous tissue theoretically could increase the risk of wound infection, an increase has not been documented [80,81].

Unnecessary procedures

Abdominal irrigation — We do not irrigate the abdomen before closing the abdominal wall. In randomized trials, intraabdominal irrigation did not reduce maternal infectious morbidity beyond the reduction achieved with prophylactic intravenous antibiotics alone, and substantially increased the frequency of intraoperative nausea and vomiting and postoperative nausea [84].

Wound irrigation — Irrigation before closure of the subcutaneous tissues at cesarean birth did not reduce the rate of surgical site infection in two randomized trials [85,86] and is probably unnecessary after routine intravenous antibiotic prophylaxis.

Irrigation has also been proposed to remove any endometrial cell contamination and thus reduce the risk of development of an incisional endometrioma. This disorder is uncommon (incidence after cesarean 0.03 to 0.45 percent) [87]. The efficacy of irrigation of the subcutaneous tissues at cesarean has not been studied; the author does not perform it.

Adhesion barriers — The body of available evidence does not support the routine use of adhesion barriers in women undergoing cesarean birth [88-90].

Formation of adhesions is common after cesarean birth; rates of 11 to 70 percent have been reported [91]. The rate of bowel obstruction after cesarean birth is much lower, ranging from 0.5 to 9 per 1000 cesarean births, with the highest risk in women who have undergone multiple cesarean births [91-93].

It has been estimated that women increase their risk of small bowel obstruction by 0.1 percent by undergoing cesarean birth and that adhesion barriers may mitigate this risk by 50 percent [94]. Based on these assumptions, 2000 women would need to have an adhesion barrier placed at cesarean birth to avoid one bowel obstruction and the cost per small bowel obstruction averted would be several hundred thousand dollars. In the only randomized trial, 753 women undergoing primary or repeat cesarean birth were assigned to receive or not receive an adhesion barrier (sodium hyaluronic acid-carboxymethylcellulose) [95]. At the subsequent delivery (n = 172 women), 76 percent of women in both groups had adhesions; severe adhesions were more common in the barrier group (33.3 versus 15.5 percent, p = 0.052). Neither group experienced a bowel obstruction.

Reapproximation of the peritoneum — We do not close the visceral or parietal peritoneum because it saves time and there is no convincing evidence of harm (such as increased adhesion formation).

In a 2014 meta-analysis of randomized trials, visceral and peritoneal non-closure decreased operative time by an average of approximately 6 minutes [96]. In addition, a large, well-designed trial that randomly assigned 533 women at primary cesarean to peritoneal non-closure or closure found no significant difference between groups in the proportion of patients with adhesions at any site or time from incision to delivery at repeat cesarean (n = 97 repeat cesareans) [97]. Strengths of this trial include that its primary objective was to examine adhesion formation at a repeat cesarean birth, use of an adhesion scoring system, exclusion of patients who had had prior pelvic or abdominal surgery, use of a standard technique for performing the cesareans, and blinding the surgeon performing the repeat cesarean to patient allocation.

However, the effect of non-closure on adhesion formation remains unclear because of the small number of patients who have undergone follow-up at a second cesarean birth. Non-closure might allow the enlarged uterus to adhere to the anterior abdominal wall or impede spontaneous closure of the peritoneum, while closure might cause a foreign body reaction to sutures and tissue damage. In a 2009 systematic review of prospective observational studies of peritoneal non-closure at cesarean birth, non-closure was associated with greater adhesion formation than closure of the parietal layer or both visceral and parietal layers (OR 2.6, 95% CI 1.48-4.56; three studies, n = 249) [98]. The studies were included if the primary objective was to examine adhesion formation at a repeat cesarean birth, had a clear study design, had an adhesion scoring system, and excluded patients who had adhesions at the primary cesarean or who had interim surgeries after the primary cesarean. Many studies were excluded from this review because of poor methodologic design or clinical heterogeneity. However, a 2011 systematic review that included many of these excluded observational studies also found that non-closure was associated with greater adhesion formation [99].

Reapproximation of rectus muscles — We and most other clinicians believe that the rectus muscles reapproximate naturally and suturing them together may cause unnecessary pain when the woman starts to move after surgery [10]. No randomized trial has evaluated rectus muscle closure versus non-closure. A prospective observational study reported a reduction in dense adhesion formation when the rectus muscles were reapproximated; however, this study did not assess pain or hematoma formation potentially related to this intervention and could not fully adjust for other intraoperative interventions, such as peritoneal closure [100].

Drains — In a 2013 meta-analysis of randomized trials of wound drainage at cesarean birth, routine use of wound drains was not beneficial [101]. Compared with no drain, routine use of drains does not reduce the odds of seroma, hematoma, infection, or wound disruption. Additionally, restricted use of subrectus sheath drains offers no benefit in maternal infectious morbidity compared with liberal use [102]. These findings also apply to obese women [103].

SKIN CLOSURE — We prefer to reapproximate the skin with subcuticular suture rather than staples. In a 2015 meta-analysis of randomized trials, women whose incisions were closed with suture had fewer wound complications than those closed with staples (relative risk [RR] 0.49, 95% CI 0.28-0.87) [104]. The decrease in wound complications was largely due to fewer wound separations with sutured closure (RR 0.29, 95% CI 0.20-0.43); differences in infection, hematoma, seroma, and readmission rates were not significant. Cosmetic appearance, pain perception at discharge, and patient satisfaction were similar for both approaches. Suture placement took 7 minutes longer than stapled closure. The staples were removed within 4 days of surgery in many trials. Delaying removal may reduce the risk of separation, but the time involved to remove staples before or after hospital discharge also needs to be considered.

The best type of suture is unclear; most surgeons use poliglecaprone (monofilament) or polyglactin (braided). A randomized trial of 275 women who underwent scheduled or nonemergent cesarean birth through a Pfannenstiel skin incision found that poliglecaprone 25 resulted in a lower rate of overall wound complications compared with polyglactin 910 (8.8 versus 14.4 percent, RR 0.61, 95% CI 0.37-0.99), but the wide confidence interval in this trial, as well as the lack of other randomized trials of this issue, preclude making a strong recommendation for one suture over the other at this time. Barbed sutures reduce closure time and may result in a better cosmetic appearance, but data are limited and not from trials of cesarean birth [105-108].

DRESSING — Postoperative surgical incisions (clean, clean-contaminated) are typically covered with a dry dressing that is held in place with an adhesive (eg, tape, Tegaderm). The choice of wound dressing depends primarily on the surgeon's preference. A systematic review concluded that the available evidence did not support a recommendation for any particular type of wound dressing nor whether covering surgical wounds reduced the risk for infection [109]. For patients undergoing cesarean birth, advanced dressings (hydrogel, hydrocolloid, alginate, film, soft polymer, capillary-acting, odor absorbent, or antimicrobial dressing) do not prevent more surgical site infections than simple dressings (basic wound contact or gauze dressing) [110]. (See "Overview of control measures for prevention of surgical site infection in adults", section on 'Intraoperative wound protectors' and "Basic principles of wound management", section on 'Wound dressings'.)

ALTERNATIVE TECHNIQUES — Several techniques to simplify the surgical approach, decrease operating time, and reduce postoperative morbidity have been proposed. It is impossible to assess which technical aspects of a particular method of cesarean birth are clearly advantageous because several aspects of the method are studied at the same time [111]. Furthermore, long-term outcomes have not been adequately evaluated.

The Pelosi [26] and Misgav Ladach (also known as modified Joel-Cohen or Joel-Cohen-Stark) (table 1) [20,21] approaches have incorporated many modifications of standard and Joel-Cohen techniques. As discussed above, the Joel-Cohen type incision is associated with less fever, pain, use of analgesia, blood loss, operating time, and hospital days compared with the standard Pfannenstiel incision (see 'Skin incision' above) and, in one randomized trial, the Joel-Cohen/Misgav Ladach method resulted in fewer patients with intraperitoneal adhesions at repeat cesarean birth (11 percent versus 36 percent after standard Pfannenstiel-Kerr approach) [112].

The Pelosi technique is illustrated by the following photographs (picture 1A-C, 1C-D). There are no randomized trials comparing the Pelosi technique with other techniques.

SPECIAL POPULATIONS

Obese women — Specific issues for cesarean birth of the obese woman are reviewed separately. (See "Cesarean birth: Patients with obesity" and "Obesity in pregnancy: Complications and maternal management".)

INCIDENTAL FINDINGS AND PROCEDURES

Bandl's ring — Bandl's ring is a pathologic constriction that forms between the thickened upper contractile portion of the uterus and the thinned lower uterine segment as a result of dystocia. It is rare and often leads to cesarean birth because of a prolonged second stage of labor. At laparotomy, the upper and lower segments of the uterus are separated by a transverse thickened muscular band. The band may trap the head or shoulders, making fetal extraction at cesarean difficult. In twin gestations, a Bandl ring can cause dystocia of the second twin.

If the fetus is difficult to extract, nitroglycerin intravenously may relax the uterus and facilitate delivery [113-115]. A vertical myometrial incision through the ring has also been recommended, but transecting the ring alone may not allow easy delivery of the fetus.

Tubal sterilization — Sterilization can be performed at cesarean birth. (See "Postpartum permanent contraception: Procedures".)

Myomectomy — Myomectomy should not be performed at cesarean birth unless the procedure cannot be safely delayed. (See "Uterine fibroids (leiomyomas): Issues in pregnancy", section on 'Indications for myomectomy during pregnancy'.)

Adnexal mass — Any adnexal mass that appears suspicious for malignancy should be removed and sent for frozen section. (See "Adnexal mass in pregnancy", section on 'Adnexal mass at cesarean delivery'.)

Appendectomy — We recommend not performing elective appendectomy at cesarean birth. It lengthens operative time and there is no strong evidence of benefit, but it also does not appear to be harmful [116]. One group suggested consideration of selective appendectomy at the time of cesarean birth in women at increased risk of having subsequent surgery to rule out appendicitis (eg, women with a palpable fecalith, abnormal appearing appendix, or history of pelvic pain or endometriosis) [116].

Hernia repair — Although combined cesarean birth and hernia repair have been reported [117,118], planned hernia repair should generally be deferred for at least four weeks postpartum to allow the lax abdominal wall to return to its baseline. (See "Overview of treatment for inguinal and femoral hernia in adults", section on 'Pregnancy'.)

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Cesarean birth".)

INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5^th to 6^th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10^th to 12^th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.

Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)

●Basics topics (see "Patient education: C-section (cesarean delivery) (The Basics)")

●Beyond the Basics topics (see "Patient education: C-section (cesarean delivery) (Beyond the Basics)")

SUMMARY AND RECOMMENDATIONS

●For the initial incision opening the abdomen, we suggest a transverse (eg, Pfannenstiel or Joel-Cohen) rather than a vertical skin incision (Grade 2C). A transverse incision is associated with better cosmetic appearance and possibly less postoperative pain and greater wound strength than the vertical midline incision. However, the incision to delivery time appears to be approximately one minute faster with vertical skin incisions. (See 'Choice of incision' above.)

●A scalpel or electrocautery can be used for tissue dissection, based on the surgeon's preference. (See 'Scalpel or electrocautery?' above.)

●The fascial incision can be extended sharply or bluntly. (See 'Fascial layer' above.)

●We leave the rectus muscles intact rather than using the Maylard technique. This improves abdominal muscle strength in the short-term. (See 'Rectus muscle layer' above.)

●We use fingers to bluntly open the peritoneum to minimize the risk of inadvertent injury to bowel, bladder, or other organs that may be adherent to the underlying surface. However, a sharp technique is also acceptable. (See 'Opening the peritoneum' above.)

●We do not routinely create a bladder flap. This saves time and reduces blood loss. (See 'Bladder flap' above.)

●For the hysterotomy, we suggest a low transverse rather than a low vertical incision for most women (Grade 2C). The low transverse incision is associated with less blood loss, less need for bladder dissection, is easier to reapproximate, and has a lower risk of rupture in subsequent pregnancies. However, a low vertical hysterotomy is preferable in some settings, such as a poorly developed lower uterine segment or lower uterine segment pathology. It also is preferable for delivery of a very large fetus (eg, anomalous, extreme macrosomia) when there is high risk of extension of a transverse incision into uterine vessels or a T or J extension may be required to extract the fetus. (See 'Hysterotomy' above.)

●We suggest blunt rather than sharp expansion of the hysterotomy incision (Grade 2B). Blunt expansion is quick and has less risk of inadvertent trauma to the fetus, and may reduce blood loss and extension of the incision. (See 'Hysterotomy' above.)

●We recommend spontaneous, rather than manual, extraction of the placenta (Grade 1A). Spontaneous extraction is associated with lower rates of endometritis and bleeding. (See 'Placental extraction' above.)

●Exteriorization or non-exteriorization of the uterus are both acceptable approaches. The choice depends on personal preference and the clinical setting. (See 'Exteriorizing the uterus' above.)

●For women who would consider a trial of labor after a previous cesarean birth, we suggest a two-layer uterine closure rather than a one-layer closure (Grade 2C). If a single layer closure is performed, we suggest an unlocked closure (Grade 2C). (See 'Single- versus double-layer closure of lower uterine segment incisions' above.)

●We suggest not closing the visceral or parietal peritoneum (Grade 2B). Non-closure saves time and there is no convincing evidence of harm (increased adhesion formation). (See 'Reapproximation of the peritoneum' above.)

●For women with subcutaneous tissue depth ≥2 cm, we recommend closure of the subcutaneous tissue layer with sutures (Grade 1A). Closure decreases the risk of subsequent wound disruption. (See 'Subcutaneous tissue' above.)

●In women who have received standard antibiotic prophylaxis, abdominal irrigation probably does not further reduce maternal infectious morbidity. Wound irrigation is also unlikely to be beneficial. (See 'Abdominal irrigation' above and 'Subcutaneous tissue' above.)

●We recommend not routinely placing a subcutaneous drain (Grade 1B). Routine use of drains does not reduce the odds of seroma, hematoma, infection, or wound disruption. (See 'Drains' above.)

●We suggest reapproximation of the skin with subcuticular suture rather than staples (Grade 2C), but either technique is reasonable. (See 'Skin closure' above.)