oPatientPlus articles are written by UK doctors and are based on research evidence, UK and European Guidelines. They are designed for health professionals to use, so you may find the language more technical than the condition leaflets.
Caesarean section rates have been steadily increasing due to a higher number of sections for fetal distress, as diagnosed by cardiotocographic (CTG) monitoring in labour, and the increasing use for breech and multiple pregnancy. The following is based on National Institute for Health and Clinical Excellence (NICE) latest guidance (November 2011).
Possible indications include:
- Cephalopelvic disproportion (use of pelvimetry is not advised).
- Malpresentation, eg breech, transverse lie.
- Multiple pregnancy.
- Severe hypertensive disease in pregnancy.
- Fetal conditions: distress, iso-immunisation, very low birthweight.
- Failed induction of labour.
- Repeat Caesarean section: two sections nearly always means subsequent births should also be by Caesarean section.
- Pelvic cyst or fibroid.
- Maternal infection, eg herpes, HIV.
Maternal request for Caesarean section is not on its own an indication and specific reasons for the request should be explored, discussed and recorded. If the request is due to anxiety about childbirth, a referral should be offered to a healthcare professional with expertise in providing perinatal mental health support to help her address her anxiety in a supportive manner.
An individual clinician has the right to decline a request for Caesarean section in the absence of an identifiable reason. However, the woman's decision should be respected and she should be offered referral for a second opinion.
Indications for emergency section
- Cord prolapse
- Failure to progress
- Fetal distress in the first stage
- Antepartum haemorrhage
- Transverse lie in labour
- Ideally performed under spinal or epidural block. This has fewer risks and allows immediate contact between the baby and mother.
- There is evidence that prophylactic antibiotics result in fewer wound infections in non-elective and elective Caesarean sections. They should be offered before the skin incision.
- Classical Caesarean section (vertical incision) is now rarely used except in:
- A very premature fetus with the lower segment poorly formed.
- A transverse lying fetus with ruptured membranes and draining liquor.
- Lower segment use made impossible by structural abnormality.
- Constriction ring present.
- Some fibroids.
- Some cases of anterior placenta praevia with lower segment abnormally vascular.
- The mother dead and rapid birth required.
- Lower uterine segment incision is nearly always used now, as uterine rupture is much less common in subsequent pregnancies and it allows better healing, reduces infection and lowers postoperative complication rates:
- The transverse incision of choice should be the Joel Cohen incision (a straight skin incision, 3 cm above the symphysis pubis; subsequent tissue layers are opened bluntly and, if necessary, extended with scissors and not a knife), because it is associated with shorter operating times and reduced postoperative febrile morbidity.
- The use of separate surgical knives to incise the skin and the deeper tissues is not recommended because it does not decrease wound infection.
- When there is a well-formed lower uterine segment, blunt rather than sharp extension of the uterine incision should be used because it reduces blood loss, incidence of postpartum haemorrhage and the need for transfusion.
- Oxytocin 5 IU by slow intravenous injection should be used to encourage uterine contraction and to decrease blood loss.
- The placenta should be removed using controlled cord traction, as this reduces the risk of endometritis.
- The uterine incision should be closed in two layers.
- Neither visceral nor parietal peritoneum should be sutured.
- Umbilical artery pH should be recorded after delivery.
- Appropriate thromboprophylaxis should be employed, according to guidelines and maternal risk factors.
Caesarean section accounts for 20-25% of all deliveries in the UK. There is significant regional variation.
Factors affecting Caesarean section rate
Factors affecting the likelihood of Caesarean section during intrapartum care include:
- Place of birth: delivering at home reduces the likelihood of Caesarean section.
- Planned childbirth in a midwifery-led unit does not reduce the likelihood of Caesarean section.
- Continuous support during labour reduces the likelihood of Caesarean section.
- Women with an uncomplicated pregnancy should be offered induction of labour beyond 41 weeks because this reduces the risk of perinatal mortality and the likelihood of Caesarean section.
- A partogram with a 4-hour action line used to monitor progress of labour of women in spontaneous labour with an uncomplicated singleton pregnancy at term reduces the likelihood of Caesarean section.
- Consultant obstetricians should be involved in the decision making for Caesarean section, because this reduces the likelihood of Caesarean section.
- Electronic fetal monitoring is associated with an increased likelihood of Caesarean section. When Caesarean section is contemplated because of an abnormal fetal heart rate pattern, in cases of suspected fetal acidosis, fetal blood sampling should be offered if it is technically possible and there are no contra-indications.
- Active management of labour and early amniotomy have not been shown to influence the likelihood of Caesarean section for failure to progress and should not be offered for this reason.
There is no influence on the likelihood of Caesarean section with walking in labour, non-supine position during the second stage of labour, immersion in water during labour, epidural analgesia during labour or the use of raspberry leaves.
The effects on the likelihood of Caesarean section of complementary therapies used during labour (such as acupuncture, aromatherapy, hypnosis, herbal products, nutritional supplements, homeopathic medicines and Chinese medicines) have not been properly evaluated.
Planned Caesarean section
The risk of respiratory morbidity is increased in babies born by Caesarean section before labour, but this risk decreases significantly after 39 weeks. Therefore, planned Caesarean section should not routinely be carried out before 39 weeks.
- Breech presentation: women who have an uncomplicated singleton breech pregnancy at 36 weeks of gestation should be offered external cephalic version. Exceptions include women in labour and women with a uterine scar or abnormality, fetal compromise, ruptured membranes, vaginal bleeding or medical conditions. If external cephalic version is contra-indicated or has been unsuccessful, Caesarean section should be offered because it reduces perinatal mortality and neonatal morbidity.
- Multiple pregnancy: if the first twin is cephalic, perinatal morbidity and mortality are increased for the second twin. However, the effect of planned Caesarean section in improving outcome for the second twin remains uncertain and therefore Caesarean section should not routinely be offered. If the first twin is not cephalic, the effect of Caesarean section in improving outcome is uncertain, but current practice is to offer a planned Caesarean section. Planned Caesarean section for uncomplicated twin pregnancy should not be carried out before 38 weeks because this increases the risk of respiratory problems in these babies.
- Preterm birth: is associated with higher neonatal morbidity and mortality. However, the effect of planned Caesarean section in improving these outcomes remains uncertain and therefore Caesarean section should not routinely be offered.
- Small-for-gestational-age babies: the risk of neonatal morbidity and mortality is higher with small-for-gestational-age babies. However, the effect of planned Caesarean section in improving these outcomes remains uncertain and therefore Caesarean section should not routinely be offered.
- Placenta praevia: if partly or completely covering the internal cervical os (grade 3 or 4 placenta praevia), delivery should be by Caesarean section:
- If there is a low-lying placenta at 32-34 weeks of gestation in women who have had a previous Caesarean section, a colour-flow Doppler ultrasound should be offered as the diagnostic test for morbidly adherent placenta.
- If the Doppler scan suggests a morbidly adherent placenta, discuss with the woman the improved accuracy of magnetic resonance imaging (MRI) to help diagnose morbidly adherent placenta and clarify the degree of invasion.
- Interventions that are available for women suspected to have a morbidly adherent placenta should be discussed, including cross matching of blood and planned Caesarean section with a consultant obstetrician present. See separate article Placenta and Placental Problems for further detail.
- Cephalopelvic disproportion: pelvimetry is not useful in predicting failure to progress in labour and should not be used in decision making about mode of birth. Shoe size, maternal height and estimations of fetal size (ultrasound or clinical examination) do not accurately predict cephalopelvic disproportion and should also not be used.
Risks versus benefits
Planned Caesarean section may reduce the risk of perineal and abdominal pain during birth and 3 days postpartum, injury to vagina, early postpartum haemorrhage and obstetric shock.
Planned Caesarean section may increase the risk of neonatal intensive care unit admission for the baby. It may also increase the risk of a longer hospital stay, hysterectomy (necessitated to stem postpartum haemorrhage) and cardiac arrest for the mother.
Mother-to-child transmission of maternal infections
- HIV-positive women:
The risk of HIV transmission from mother to child is the same for a Caesarean section and a vaginal birth if the woman is on highly active antiretroviral therapy with a viral load of fewer than than 400 copies per ml, or the woman is on any antiretroviral therapy with a viral load of fewer than 50 copies per ml. Caesarean section should not be advised to reduce risk of transmission in these circumstances.
- Mother-to-child transmission of hepatitis B can be reduced if the baby receives immunoglobulin and vaccination and, in these situations, pregnant women with hepatitis B should not be offered a planned Caesarean section, because there is insufficient evidence that this reduces mother-to-child transmission of hepatitis B virus.
- Women who are infected with hepatitis C should not be offered a planned Caesarean section because this does not reduce mother-to-child transmission of the virus. Caesarean section does reduce mother-to-child transmission of both hepatitis C virus and HIV if infected with both.
- Women with primary genital herpes simplex virus (HSV) infection occurring in the third trimester of pregnancy should be offered planned Caesarean section because it decreases the risk of neonatal HSV infection.
- Pregnant women with a recurrence of HSV at birth should be informed that there is uncertainty about the effect of planned Caesarean section in reducing the risk of neonatal HSV infection. Therefore, Caesarean section should not routinely be offered in this situation.
Repeat Caesarean section
Women who have had up to and including four Caesarean sections should be advised that the risk of fever, bladder injuries and surgical injuries does not vary with planned mode of birth. The risk of uterine rupture, although higher for planned vaginal birth, is rare. Therefore the decision about mode of birth after a previous Caesarean section should take into consideration:
- Maternal preferences and priorities.
- Risk of uterine rupture: a rare complication. One systematic review found an additional risk of 2.7 symptomatic ruptures per 1,000 when comparing trial of labour with elective repeat Caesarean section.
- Risk of perinatal mortality and morbidity: the risk of an intrapartum infant death is small for women who have a planned vaginal birth (about 10 per 10,000), but higher than for a planned repeat Caesarean section (about 1 per 10,000). The effect of planned vaginal birth or planned repeat Caesarean section on cerebral palsy is uncertain.
Women who have had a previous Caesarean section should be offered electronic fetal monitoring during labour and care during labour, in a unit where there is immediate access to Caesarean section and on-site blood transfusion services.
Women who have had a previous Caesarean section can be offered induction of labour, but both women and healthcare professionals should be aware that the likelihood of uterine rupture in these circumstances is increased to:
- 80 per 10,000 when labour is induced with non-prostaglandin agents.
- 240 per 10,000 when labour is induced using prostaglandins.
- A low-residue diet during labour (toast, crackers, low-fat cheese) results in larger gastric volumes, but the effect on the risk of aspiration if anaesthesia is required is uncertain.
- Isotonic drinks during labour prevent ketosis without a concomitant increase in gastric volume.
- Delivery at emergency Caesarean section for immediate threat to life of mother or fetus (category 1 indication) should be accomplished as quickly as possible, taking into account that rapid delivery has the potential to do harm. A decision-to-delivery interval of less than 30 minutes is not critical in influencing baby outcome, but has been an accepted audit standard for response to emergencies within maternity services. A category 2 indication (compromise that isn't immediately life-threatening) for delivery should be achieved between 30 and 75 minutes.
- Intraoperative blood cell salvage:
- Blood shed during an operation is collected, filtered and washed to produce autologous red blood cells for transfusion to the patient.
- Intraoperative blood cell salvage is an effective technique for blood replacement, but there are theoretical safety concerns when it is used in obstetric practice.
- This procedure should only be performed by multidisciplinary teams who develop regular experience of intraoperative blood cell salvage.
- Women who have needed an emergency Caesarean section should have the reasons explained to them before they are discharged from hospital. Printed information should also be given as to their options for delivery in future pregnancies.
- Lung aspiration.
- Pulmonary embolus.
- Postpartum haemorrhage.
- Longer stay in hospital may lead to difficulties in bonding and adjustment difficulties for the mother and the rest of the family.
The balance of maternal and fetal risks between Caesarean section and vaginal delivery is difficult; in an emergency scenario it is almost impossible to differentiate the consequences of Caesarean section from the indication for the operation. In this year's triennial report only one Caesarean section was performed at maternal request. The remaining women had serious prenatal or intrapartum complications or illness that required a Caesarean section to try to save either their or their baby's life.
Further reading & references
- Quality standard for caesarean section, NICE (Jun 2013)
- Caesarean section, NICE Clinical Guideline (November 2011)
- Prevention and treatment of surgical site infection, NICE Clinical Guideline (October 2008)
- Reducing the Risk of Thrombosis and Embolism during Pregnancy and the Puerperium; Royal College of Obstetricians and Gynaecologists (November 2009)
- Fairley L, Dundas R, Leyland AH; The influence of both individual and area based socioeconomic status on temporal BMC Public Health. 2011 May 18;11:330.
- Guise JM, McDonagh MS, Osterweil P, et al; Systematic review of the incidence and consequences of uterine rupture in women with previous caesarean section.; BMJ. 2004 Jul 3;329(7456):19-25.
- Saving Mothers' Lives. Reviewing maternal deaths to make motherhood safer: 2006-2008; Centre for Maternal and Child Enquiries (CMACE), BJOG, Mar 2011
Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. EMIS has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.
Dr Colin Tidy
Dr Hayley Willacy
Dr John Cox