Caesarean Section

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Caesarean section\: delivery of a baby through a surgical incision in the abdominal and uterine walls.
Rates\: 25-30% of births in the UK (2015); 67% for women with a previous caesarean section.
Classi
Category 1\: Immediate ("crash"), threat to life of woman or fetus; recommended within 30 minutes.
Category 2\: Urgent, maternal or fetal compromise (not immediately life-threatening); recommended within 75 minutes.
Category 3\: Scheduled, early delivery required, no immediate compromise.
Category 4\: Elective, planned to suit woman and sta
Indications\:
Category 1\: Cord prolapse, sustained fetal bradycardia, fetal hypoxia, placental abruption, uterine rupture.
Category 2\: Failure to progress in labour with pathological CTG.
Category 3\: Intrauterine growth restriction, failed induction of labour, breech in labour.
Category 4\: Previous caesarean section, breech presentation, other malpresentations, certain twin pregnancies, placenta
praevia, maternal HIV, primary genital herpes in the third trimester, previous hysterotomy or classical caesarean section,
maternal diabetes with estimated fetal weight >4.5kg, maternal request.
Procedure\:
Pre-operative steps\: Check haemoglobin, correct anaemia, group & save, H2-receptor antagonists or PPIs, anti-emetics,
assess for thrombo-prophylaxis, prophylactic antibiotics, iodine-based vaginal wash if membranes ruptured, indwelling
urinary catheter.
Anaesthesia\: Prefer regional (spinal or epidural) over general anaesthesia. General anaesthesia reserved for maternal
contraindications or immediate fetal concerns.
Types\: Lower uterine segment incision (Pfannenstiel or Joel-Cohen incision), classical caesarean section (vertical incision,
rare, indicated in speci
Complications\:
Intraoperative\: Anaesthetic side e
ureteral injury.
Postoperative\: Pain, infection (endometritis, wound infection, UTIs), venous thromboembolism, pulmonary atelectasis,
return to theatre, longer hospital stay.
Future pregnancies\: Increased risk of abnormal placentation, uterine rupture, repeat caesarean section, antepartum
stillbirth.
Fetal/neonatal\: Fetal laceration, transient tachypnoea of the newborn, admission to neonatal unit.
VBAC (Vaginal Birth After Caesarean)\:
Appropriate for singleton pregnancies with cephalic presentation at 37 weeks and one previous lower uterine segment
caesarean section.
Contraindicated in previous uterine rupture, classical caesarean section, or contraindications to vaginal delivery (e.g., major
placenta praevia).
Success rate\: 72-75%, up to 90% if previous successful vaginal delivery.
Continuous fetal monitoring recommended.
Article 🔍
A comprehensive topic overviewIntroduction
A caesarean section is the delivery of a baby through a surgical incision in the abdominal and uterine wall(s).
Over the past couple of decades, the rates of caesarean sections have increased signi
United Kingdom, 25-30% of births were delivered by caesarean section in 2015. In women who have had at least one
previous caesarean section, the rate of deliveries by this method increases to 67%.
1
Figure 1. A caesarean section being
performed.
2
In this article, we will discuss the classi
procedure and associated complications.

Classi

Caesarean sections can be classi
1
Category 1 - immediate (“crash”)\: these are performed when there is an immediate threat to the life of the woman or
fetus. Delivery should take place as soon as possible. The Royal College of Obstetricians and Gynaecologists
recommends that a category 1 section should be performed within 30 minutes of making the decision for caesarean
delivery.
Category 2 - urgent\: these are indicated when there is maternal or fetal compromise, which is not immediately life-
threatening. To be performed as soon as possible, and within 75 minutes of decision for delivery.
Category 3 - scheduled\: this category of C-section is indicated where there is no maternal or fetal compromise, but
early delivery is required.
Category 4 - elective\: the timing of this delivery is planned to suit the woman and sta

Indications

Indications for a category 1 (crash) caesarean section include\:
Cord prolapse
Sustained fetal bradycardia
Fetal hypoxia (scalp pH \< 7.20)
Placental abruption
Uterine rupture
Indications for a category 2 (urgent) caesarean section include\:
Failure to progress in labour with pathological CTG
Indications for a category 3 (scheduled) caesarean section include\:
Intrauterine growth restriction with poor fetal function tests
Failed induction of labour
Breech in labour
Indications for a category 4 (elective) caesarean section include\:
Previous caesarean section
Breech presentationOther malpresentations
Twin pregnancy where the
Placenta praevia
Maternal HIV
Primary genital herpes in the third trimester
Previous hysterotomy or “classical” caesarean section
Maternal diabetes with an estimated fetal weight >4.5kg in cases where vaginal delivery is unlikely to be successful
Maternal request
Elective caesarean sections are normally planned around 39 weeks gestation. This is to reduce the risk of the neonate
developing respiratory distress in neonates born at earlier gestations, known as transient tachypnoea of the newborn.

Procedure

Peri-operative and anaesthetic concerns
Before a caesarean section, there are several steps and investigations that should be performed to reduce morbidity
associated with the procedure\:
Pre-operative haemoglobin check and correction of anaemia. A group & save should also be taken.
H2-receptor antagonists or proton pump inhibitors (currently o
Metoclopramide is a prokinetic anti-emetic agent, and this can help reduce the risk of aspiration of gastric contents.
Women should be risk-assessed and appropriate thrombo-prophylaxis should be prescribed. This includes
compression stockings, hydration, early mobilisation and low-molecular-weight heparin as appropriate.
Prophylactic antibiotics should be given immediately prior to the skin incision.
In cases of ruptured membranes, an iodine-based vaginal wash is recommended pre-operatively to reduce the risk of
endometritis.
An indwelling urinary catheter should be inserted for the duration of the procedure to prevent over-distension. This
reduces the risk of damage to the bladder during the surgery. The catheter can be removed once the woman is mobile
after regional anaesthesia, but no sooner than 12 hours after the last “top-up” dose of anaesthetic.
Regional anaesthesia is preferred to general anaesthesia. Most caesarean sections are performed under a spinal or
“topped-up” epidural anaesthesia.
Caesarean section under general anaesthesia is reserved for cases where there is a maternal contraindication for
regional anaesthesia, where spinal or epidural anaesthesia fails to achieve an adequate block or more commonly for
category 1 sections where there is an immediate concern for fetal wellbeing.
General anaesthesia for an emergency caesarean section should include pre-oxygenation, cricoid pressure and rapid
sequence induction to reduce the risk of aspiration of gastric contents.
All types of anaesthetic require a left lateral tilt of up to 15 degrees for uterine displacement to prevent maternal
hypotension (e.g. via insertion of a wedge cushion).
Types of caesarean section
Lower uterine segment incision
There are two types of skin incisions for this type of caesarean section\: the Pfannenstiel incision (Figure 2) and a Joel-
Cohen incision.
NICE recommends a Joel-Cohen incision, de
layers are opened bluntly. This allows for a shorter operating time and reduces the incidence of postoperative febrile
illness.Figure 2. A Pfannenstiel incision.
3
Abdominal wall layers
The layers of the abdominal cavity opened and closed during a caesarean section include\:
Skin
Subcutaneous tissue (including Scarpa’s fascia)
Rectus sheath
Rectus muscle
Parietal peritoneum
Uterus including visceral peritoneum
Classical caesarean section
This procedure is rarely performed as it involves a vertical incision into the upper uterine segment.
A classical caesarean section may be indicated in the following cases\:
Structural abnormality of the uterus
Di
Where hysterectomy will follow caesarean delivery (e.g. in cases of morbidly adherent placenta)
Post-mortem caesarean section where the fetus is viable
Cervical cancer
Anterior placenta previa with abnormally vascular lower uterine segment
Transverse lie with ruptured membranes
Very preterm fetus where the lower uterine segment is poorly formed
Classical caesarean sections are associated with greater rates of adhesions and infections compared to lower uterine
segment incisions.
The closure of a classical caesarean section is more complicated and takes longer to complete. Following dissection of the
abdominal and uterine walls, and delivery of the fetus,
the placenta by controlled cord traction. Once the uterine cavity has been emptied, the uterus is closed with two layers.
The rectus sheath and skin are closed either with continuous or interrupted sutures or staples.

Complications

When compared to vaginal delivery, caesarean section has lower rates of perineal trauma and pain. However, primary
caesarean section has a higher incidence of abdominal pain, venous thromboembolism, bladder or ureteric injury and
hysterectomy.
Complications of caesarean section can further be divided into intraoperative and postoperative complications.
Intraoperative complications
Intraoperative complications occur in 12-15% of caesarean sections and are more common in women undergoing an
emergency caesarean section. These may include\:
4
Anaesthetic side e
Haemorrhage sometimes requiring blood transfusion and, rarely, hysterectomy (7-8/1000)Uterine or uterocervical lacerations
Bladder or bowel lacerations +/- repair
Ureteral injury
The risk of haemorrhage is increased in women with a high BMI, placenta praevia or placental abruption or in cases of very
high or low birthweight.
Postoperative complications
Postoperative complications can occur in up to one-third of women. These include\:
Pain\: opioid analgesia is used
in
Infection\: endometritis, wound infection and urinary tract infections. Occurs in approximately 8% of women undergoing
caesarean section. Where the woman’s body mass index is greater than 35, negative pressure dressings may be
considered to decrease the risk of wound infection.
Venous thromboembolism
Pulmonary atelectasis
Return to theatre for another procedure
Longer hospital stay compared to vaginal delivery
Complications a
Abnormal placentation (e.g. accreta spectrum/praevia)
Uterine rupture
Repeat caesarean section
For women who have had a previous caesarean section, the risk of placenta praevia and placenta accreta increases in
subsequent pregnancies. There is also a higher risk of antepartum stillbirth in subsequent pregnancies and this risk
increases with each successive caesarean section performed.
5
Fetal/neonatal complications may include\:
Fetal laceration risk of 2%
Transient tachypnoea of the newborn
Admission to a neonatal unit
Vaginal birth after caesarean section (VBAC)
Vaginal birth after caesarean section is an appropriate option and may be o
pregnancy with a cephalic presentation at 37 weeks who had a single lower uterine segment caesarean section in
the past, with or without previous vaginal deliveries.
6
VBAC is contraindicated in women who have had a previous uterine rupture or classical caesarean section, or for
women where vaginal delivery is contraindicated irrespective of the presence of a scar (e.g. in major placenta
praevia).
A planned VBAC is associated with a 0.05% risk of uterine rupture.
The success rate of planned VBAC is 72-75%, however, may be as high as 90% in women who have had a previous
successful vaginal delivery, which is the greatest predictor of a successful VBAC.
Continuous fetal monitoring should be utilised during the delivery as a change in fetal heart rate can be an early
sign of impending uterine scar rupture.
Women should be counselled that the risk of uterine rupture increases two to three-fold with the use of uterotonic
agents or prostaglandins in induced or augmented labour.References
National Institute for Health and Care Excellence. C a e s a r e a n b i r t h . March 2021. Available from\: [LINK]
Mediajet. C a e s a r e a n s e c t i o n . License\: [CC BY-SA]
DRosenbach. P f a n n e n s t e i l i n c i s i o n . License\: [CC BY-SA]
Shellhaas, Cynthia S et al.
Obstetrics and gynecology 114,2 Pt 1 (2009)\: 224-229.
“The frequency and complication rates of hysterectomy accompanying cesarean delivery.
”
Keag, Oonagh E et al. Long-term risks and bene
pregnancies\: Systematic review and meta-analysis. 2018. Available from\: [LINK]
Royal College of Obstetricians and Gynaecologists, Birth after caesarean section\: Green top guideline no.45. 2015 Available
from\: [LINK]
Collins S, Arulkumaram S et al, Oxford Handbook of Obstetrics and Gynaecology 3 rd
Edition, Oxford University Press, 2013

Reviewer

Dr Barbara Burke
Registrar in Obstetrics and Gynaecology
Cork University Maternity Hospital

Related notes

Amniotic Fluid Embolism
Antenatal Screening for Down’s Syndrome
Antepartum Haemorrhage (APH)
Breech Presentation
Cord Prolapse

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Contents

Introduction
Classi
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