Caesarean Section

Caesarian section rates have been steadily increasing due to a higher number of sections for fetal distress as diagnosed by CTG monitoring in labour and the increasing use for breech and multiple pregnancy.¹

Possible indications include:¹

• Cephalo-pelvic disproportion
• Malpresentation: e.g. breech, transverse lie
• Multiple pregnancy
• Severe hypertensive disease in pregnancy
• Fetal conditions: distress, iso-immunisation, very low birth weight
• 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 e.g. herpes, HIV

Indications for emergency section

• Cord prolapse
• Failure to progress
• Fetal distress in the first stage
• Antepartum haemorrhage (abruption or placenta praevia)
• Transverse lie in labour

Maternal request for caesarean section: not on its own an indication for caesarean section and specific reasons for the request should be explored, discussed and recorded. Any underlying issues, e.g. fear of childbirth, should be addressed. 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.

• Ideally performed under spinal or epidural block. This has fewer risks and allows immediate contact between the baby and mother.
• Classical caesarean section (vertical incision) now rarely used except in:
  • Very premature fetus with lower segment poorly formed
  • 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
  • Mother dead and rapid birth required
• Lower uterine segment incision: nearly always used now as uterine rupture is much less common in subsequent pregnancies, allows better healing, reduces infection and lower post-operative complication rates

Accounts for 20% of all deliveries in the UK

Factors affecting caesarean section rate¹

Factors affecting 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 contraindications.
• 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.

No influence on likelihood of caesarean section: walking in labour, non-supine position during the second stage of labour, immersion in water during labour, epidural analgesia during labour, 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.

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 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 contraindicated or has been unsuccessful, Caesarian section should be offered because it reduces perinatal mortality and neonatal morbidity.
• Multiple pregnancy: if the first twin is cephalic, perinatal morbidity and mortality is 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: 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 covers the internal cervical os (grade 3 or 4 placenta praevia), delivery should be by Caesarian section.
• 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.

Mother-to-child transmission of maternal infections

• HIV-positive women who are pregnant should be offered a planned Caesarian section because it reduces the risk of mother-to-child transmission of HIV
• 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. Caesarian 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 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.

The risks and benefits of vaginal birth after caesarean section compared with repeat caesarean section are uncertain. Therefore the decision about mode of birth after a previous caesarean section should take into consideration:

• Maternal preferences and priorities
• Risk of uterine rupture: rare complication. One systematic review found an additional risk of 2.7 symptomatic ruptures per 1000 when comparing trial of labour with elective repeat caesarean section.²
• 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 health care 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 prevents ketosis without a concomitant increase in gastric volume
• Delivery at emergency caesarean section for maternal or fetal compromise 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.
• Intraoperative blood cell salvage:³
  • 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.

• Lung aspiration
• Pulmonary embolus
• Post partum haemorrhage
• Infection
• Longer stay in hospital may lead to difficulties in bonding and adjustment difficulties for the mother and the rest of the family

The maternal mortality for planned Caesarean section under regional block at term is 1 in 10,000, which is ten times that for vaginal delivery.¹