Cesarean delivery (CD, colloquially known as a C-section) is the operative delivery of ≥ 1 infants through a surgical incision in the maternal abdomen and uterus.
- Incidence in the United States:
- Now about 1 in 3 deliveries in the United States are by CD (higher than in most other developed countries)
- In 1970, only approximately 5% of deliveries were by CD.
- Incidence rates globally:
- Average rate for developed countries: approximately 20%
- Average rate for less developed regions: approximately 15%
- Average rate for least developed regions: approximately 2%
- There is evidence from the WHO that the optimal CD rate allowing for maximum maternal and fetal survival is about 15% of all deliveries.
Cesarean deliveries can be classified in several ways:
- By the type of uterine incision
- Primary or repeat CD:
- Primary: a mother’s 1st CD (though it may not be her 1st delivery)
- Repeat: a mother who has undergone prior CD
- “3-peat,” “4-peat,” etc.: colloquial language used among clinicians to communicate the number of prior CDs a woman has undergone (e.g., “3-peat” = 3rd CD)
- By urgency: Categories are fluid, and can change rapidly; these categories are generally used to communicate and coordinate care between teams working together (e.g., the obstetric, anesthesia, and pediatric teams).
- Mothers with indications prior to the onset of labor
- Delivery is scheduled days to weeks in advance.
- If mothers go into labor early, the CD is done at that time.
- These CDs carry the lowest risk.
- Routine unscheduled:
- Mothers in labor who develop indications for CD intrapartum but delays of up to several hours pose no additional risk to the mother or infant.
- Example: mother with arrest of labor, no signs of infection, and infant with a reassuring fetal heart rate pattern
- Mothers in labor who develop indications for CD intrapartum who need to be delivered within the next 30 minutes
- Example: infant develops persistent recurrent late decelerations (indicating fetal distress), though still shows moderate variability (showing infant is likely not yet acidotic).
- All teams should move quickly, but safely, and follow all standard protocols.
- Mothers who need to be delivered as fast as humanly possible
- Example: placental abruption with significant maternal and fetal bleeding (infants can completely exsanguinate within minutes)
- Teams move as quickly as possible (i.e., running), and imperfect adherence to protocols may be acceptable (e.g., preparation includes simply dumping the bottle of Betadine across the maternal abdomen).
Indications and Contraindications
Indications for CD may be maternal, placental, or fetal, though there is often overlap in these categories.
These indications are present prior to the onset of labor. These mothers should be scheduled for CD and (in general) not be allowed to go into labor.
- Prior CD with a low transverse incision:
- Current obstetric practice is to give the mothers a choice between attempting a trial of labor after cesarean (TOLAC) and scheduling a repeat CD.
- Risks are considered comparable but different.
- Joint decision-making is recommended; consider circumstances surrounding the prior delivery, characteristics of this pregnancy, available resources, and mother’s preference.
- Prior uterine surgery:
- History of a classical or T-type uterine incision in prior CD
- History of a myomectomy (excision of fibroids) that involved the full thickness of the myometrium
- Prior history of uterine dehiscence
- History of trachelectomy (surgical excision of the cervix)
- Women with medical conditions that present a contraindication to Valsalva/pushing:
- Certain maternal cardiac and pulmonary diseases (e.g., pulmonary hypertension)
- Cerebral aneurysm or arteriovenous malformations
- Mentum posterior face presentations (infant’s chin is pointing toward the maternal pubic symphysis with its head fully extended back toward the maternal sacrum)
- Transverse presentations
- Abnormalities of the maternal bony pelvis
- Infants with certain congenital malformations of skeletal disorders
- Placental abnormalities:
- Placenta previa: The placenta covers (partially or completely) the internal cervical os.
- Placenta accreta spectrum: a spectrum of abnormal placentation in which the placenta is abnormally and firmly adherent to the uterine wall
- Placenta accreta: The placenta attaches directly to the myometrium because of partial or total absence of the decidua basalis.
- Placenta increta: Placental villi are invading the myometrium.
- Placenta percreta: The placental villi penetrate through the entire myometrium and may invade other surrounding structures.
The 2 primary intrapartum indications are fetal intolerance of labor and arrest of labor.
Fetal intolerance of labor:
- Definition: nonreassuring fetal monitoring (NRFM) despite resuscitative measures
- Category 3 fetal heart rate tracing
- Persistent category 2 fetal heart rate tracing
- Reasons for NRFM (though often no reason is identified):
- Placental abruption: premature separation of the placenta leading to hemorrhage
- Uterine rupture
- Intraamniotic infection (i.e., chorioamnionitis):
- Infection of the amniotic fluid, membranes, placenta, umbilical cord, or fetus
- Usually caused by bacteria ascending from the vagina
- Uteroplacental insufficiency:
- Inability of the placenta to deliver a sufficient supply of oxygen and nutrients to the fetus
- Common etiologies include maternal vascular disease, severe maternal anemia, smoking or cocaine use, and uterine malformations.
- Umbilical cord prolapse:
- An obstetric emergency
- Management: Whoever detects the prolapsed cord on exam needs to keep the hand in the vagina, elevate the fetal head off the cervix, and keep the hand there until the infant is delivered via CD.
- 2-vessel umbilical cord
- Tight nuchal cord (umbilical cord is wrapped around the infant’s neck)
- Fetal anomalies/congenital syndromes (e.g., trisomy 13 or 18)
- Maternal death: CD performed shortly after maternal death is known as a postmortem CD.
Arrest of labor:
- Arrest of dilation:
- No cervical dilation over an extended period of time
- Diagnosed when the cervix is ≥ 6 cm dilated AND there has been:
- No cervical change for ≥ 4 hours despite adequate contractions OR
- No cervical change for ≥ 6 hours regardless of contraction adequacy
- Arrest of descent: no descent of the infant with pushing for ≥ 2 hours
- Failed operative vaginal delivery (e.g., attempted forceps or vacuum-assisted deliveries that were unsuccessful)
- Active genital herpes infection at the onset of labor: high risk of vertical transmission to the fetus, with potential for serious encephalopathy and death
- Poorly controlled HIV infection at the onset of labor: high risk of vertical transmission
- Suspected fetal macrosomia (large infants)
Cesarean delivery on maternal request
Cesarean delivery on maternal request (CDMR) is controversial and entails a CD performed at the request of the mother in order to avoid vaginal delivery, in the absence of any medical indication.
- Limited data, no randomized trials → recommendations are based on expert opinion
- Data suggest no benefit of CDMR to:
- Maternal mortality
- Postpartum sexual function
- Pain remote from delivery
- A CDMR is generally not recommended by professional and other health organizations due to ↑ risk associated with CD over vaginal delivery (well-established risk levels with high-quality evidence).
- After extensive counseling of the mother, CDMR may be performed by willing providers.
- Cesarean delivery on maternal request is considered acceptable because:
- Despite the ↑ risk of planned CD over a vaginal delivery, there is no guarantee that a trial of labor will result in a vaginal delivery, and an intrapartum CD is higher risk than a planned CD.
- Respect for mother’s autonomy: Well-counseled mothers have the right to make informed decisions about their health care.
- Purely elective surgery is acceptable in other circumstances (e.g., cosmetic surgery).
Contraindications to cesarean delivery
- The only absolute contraindication to CD is maternal refusal (even in cases of impending fetal death).
- Relative contraindication: intrauterine fetal death (death in utero) in a mother with no other indications for CD
Adequate pain control is required in order to safely perform a C-section. Options include:
- Spinal anesthesia:
- Typically, the preferred anesthesia for CD
- Single injection of opioid into the subarachnoid space
- Pain relief:
- Lasts 2–4 hours
- Excellent pain relief from T10 and below
- Epidural anesthesia:
- Generally used for laboring mothers, though can be administered as a bolus just prior to CD if needed
- Slow-flow continuous administration of opioid into the epidural space via a catheter
- Pain relief:
- Continuous pain relief while running
- Excellent pain relief from T8 and below
- May have some “hot spots” (areas of poor pain relief)
- General anesthesia:
- Reserved for emergency C-sections → spinal anesthesia should always be attempted first if time allows (unless there are specific contraindications to spinal)
- Increases risk for:
- Maternal aspiration → aspiration pneumonitis
- Postpartum hemorrhage (general anesthesia causes uterine atony)
- Fetal respiratory depression at birth (infant will be born with general anesthesia in its system)
- Local anesthesia:
- Only used with maternal consent when a true emergent CD is required and no anesthesia providers are immediately available
- Lidocaine is injected into each layer of tissue by the surgeon.
- Still extremely painful for the mother because of incomplete anesthesia, especially within the abdominal cavity
The 2 primary types of skin incisions include:
- Pfannenstiel incision:
- Preferred incision unless a need for increased surgical exposure is anticipated
- A transverse incision made approximately 2–3 cm above the symphysis pubis.
- Pros: ↓ risk of dehiscence; cosmetically preferred
- Cons: ↓ exposure to the abdominal cavity compared to a midline incision
- Vertical midline incision:
- Pros: marginally faster entry into the abdomen (though most trained obstetricians can get into the abdominal cavity via a Pfannenstiel incision in < 30 seconds)
- Cons: higher rate of dehiscence
- Very rarely used
Layers of tissue (in order)
- Subcutaneous fat
- Rectus abdominis muscles (separated in the midline)
- Uterus (Note: The bladder should be identified and moved out of the surgical field.)
There are several types of incisions that can be made on the uterus to deliver the baby. Where the incision is made has a significant impact on future pregnancies. A uterine incision is called a hysterotomy.
- Low transverse incision:
- Most common uterine incision
- Made in the lower uterine segment
- Noncontractile part of the uterus → least likely to rupture
- Less blood loss
- Easier repair
- Lowest risk of uterine rupture in future pregnancies (approximately 1% with a single low transverse incision)
- Low vertical incision:
- A vertical incision in the lower uterine segment
- Suspect additional space will be needed to extract the fetus (e.g., malpresentations such as transverse back down, extreme macrosomia)
- Pathology in the lower uterine segment (e.g., large fibroid)
- Densely adherent bladder
- Primary disadvantage is ↑ risk of incision extension:
- Down into the bladder, cervix, or vagina (injury to these organs)
- Up into fundus (unintentional classical incision)
- Classical incisions:
- Vertical incision through the fundus
- Incision is through the strong, contractile portion of the uterus → high risk of rupture in subsequent pregnancies
- Same indications as a low vertical incision, but unable to make incision in the lower uterine segment
- Extreme prematurity (before the lower uterine segment has developed)
- Postmortem delivery
- T incision and J incisions:
- Vertical upward extensions off a low transverse incision
- T extensions are in the midline and J extensions are on a lateral edge.
- Done when a low transverse incision has already been made but is insufficient to deliver the infant
- High risk of rupture in future pregnancies
Delivery and repair
- Uterine contents removed:
- Infant (handed to pediatric care providers in attendance)
- Placenta and all fetal membranes
- Repair of the hysterotomy:
- The uterus is closed in 1 or 2 layers.
- 1st goal is to achieve hemostasis.
- Recall: Blood flow to the uterus at term may be as fast as 750 mL/min.
- Average blood loss at CD is about 1000 mL, the vast majority of which comes from bleeding at the hysterotomy (despite this, the need for blood transfusions is uncommon).
- Fascia is always sutured closed.
- Subcutaneous fat may or may not be reapproximated, depending on thickness.
- Skin is typically closed with subcutaneous sutures or staples.
Complications and Risks
Planned and routine CDs have the lowest complication rates, while emergent CDs have the highest. Serious complications include:
- Postpartum hemorrhage
- Need for blood transfusion
- Emergent hysterectomy
- Injury to surrounding pelvic organs, especially the bladder
- Venous thromboembolism (VTE)
Risks of cesarean versus vaginal delivery
In general, CDs are associated with higher risks than spontaneous vaginal deliveries. Examples of increased risks include:
- Maternal mortality: 2.2 per 100,000 CDs vs. 0.2 per 100,000 spontaneous vaginal deliveries
- Postpartum hemorrhage
- Postpartum infections:
- Surgical site infections/wound infections
- Bladder injury
- ↑ Risk in future pregnancies:
- Uterine rupture with labor
- Placenta accreta spectrum
- Placenta previa
Routine care following a cesarean delivery
- Can begin as soon as the mother is able to safely hold her infant, provided she is otherwise clinically stable → typically in the recovery room, immediately following surgery
- Give breastfeeding mothers only medications that are safe in lactation.
- Monitor vital signs.
- Urine output:
- Should be monitored for early signs of hypovolemia
- Urinary catheters should be removed once the mother is able to ambulate to the toilet or bedside commode, typically between several hours and 1 day after giving birth.
- Incisions and dressings:
- Incisions should be kept clean and dry.
- Dressings are typically removed on postoperative day 1, unless a mother is at higher risk for dehiscence.
- Pain control:
- Like any abdominal surgery, adequate postoperative pain control is required.
- Mothers who labored may also have vaginal discomfort and/or lacerations.
- Typically managed with scheduled NSAIDs (e.g., ibuprofen) and a narcotic as needed
- Ambulation should be encouraged to reduce the risk of VTE.
- Follow up CBC on postoperative day 1: to rule out serious anemia
Mothers should typically be advised to:
- Avoid intercourse and/or anything in the vagina (i.e., “pelvic rest”) to allow time for healing.
- Avoid heavy lifting (anything that requires straining, typically about 10 lb) until they are comfortable doing so (usually about 4–6 weeks).
- Avoid driving until:
- Off narcotics
- Comfortable that they could slam on the breaks in an emergency
- Typically 2–3 weeks
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- Cunningham, F. G., Leveno, K. J., et al. (2010). Williams Obstetrics, 23rd ed., pp.544–555.
- Berghella, V. (2021). Cesarean delivery: surgical technique. In Barss, V.A. (Ed.), UpToDate. Retrieved July 16, 2021 from https://www.uptodate.com/contents/cesarean-delivery-surgical-technique
- Berghella, V. (2021). Cesarean delivery: preoperative planning and patient preparation. In Barss, V.A. (Ed.), UpToDate. Retrieved July 16, 2021 from https://www.uptodate.com/contents/cesarean-delivery-preoperative-planning-and-patient-preparation
- Berghella, V. (2021). Cesarean delivery: postoperative issues. In Barss, V.A. (Ed.), UpToDate. Retrieved July 16, 2021 from https://www.uptodate.com/contents/cesarean-delivery-postoperative-issues