Why a caesarean section is necessary 

A caesarean section is usually performed when a normal vaginal birth could put you or your unborn baby at risk. 

It can either be planned or carried out as an emergency procedure.

Planned caesarean section

Before you give birth, your midwife or doctor should discuss the benefits and risks of having a caesarean section compared with a planned vaginal birth.

Medical reasons for having a planned caesarean section include: 

  • severe pre-eclampsia – this is pregnancy-related high blood pressure and requires emergency treatment
  • position of the baby – your baby may be in an abnormal position inside the womb, such as the breech position, which makes it unlikely to fit through the birth canal
  • two or more previous caesarean sections
  • if you are expecting twins or other multiple births – the babies may be premature and more safely delivered through caesarean section; one or more of the babies may be in an abnormal breech position (bottom or feet first), or two or more of the babies may share a placenta, which means a caesarean section is necessary to avoid the babies being deprived of oxygen
  • small pelvis – scans sometimes show that the baby's head is larger than the space in the mother's pelvis through which it needs to travel
  • placenta praevia – when the placenta blocks the exit to the womb
  • infection – if you have certain viral infections, such as a first attack of genital herpes, you may be offered a caesarean section because a normal delivery would risk transferring the virus to your baby
  • a medical condition – for example, a heart problem may put you at risk during a normal delivery
  • restricted growth of the baby – some babies who are not growing well in the womb have a higher risk of dying or being ill around the time of birth.

Emergency caesarean

In an emergency, there may not be enough time to discuss fully the advantages and disadvantages of a caesarean section. If vaginal delivery poses significant risks to your own or your baby's health, the midwife or doctor will decide with you if a caesarean section is the safest option.

Reasons for needing an emergency caesarean include:

  • your unborn baby not getting enough oxygen, and a vaginal delivery will take too long and put your baby at risk
  • your labour not progressing, despite your efforts to move the baby sufficiently and quickly down the birth canal (from the womb through to the vagina)
  • your labour being induced for a medical reason, but the methods used are failing to produce contractions effective enough to lead to a vaginal delivery
  • you have a lot of vaginal bleeding during your labour

In some emergency situations, a baby may need to be delivered very quickly, even within half an hour. In such emergencies, a caesarean section is the safest way to protect both you and your baby.

Older women

Statistically, women over 35 years old are more likely to need a caesarean section, because they have an increased risk of certain complications during pregnancy, such as:

  • high blood pressure
  • gestational diabetes
  • slow widening (dilation) of the cervix
  • having a large baby
  • the baby adopting an awkward position in the womb, such as the breech position
  • placenta praevia

If you're anxious about childbirth

If you request a caesarean because you're anxious about childbirth, you should be referred to a healthcare professional who can provide you with appropriate mental health support.

If after discussion and support you still feel a vaginal birth is not an acceptable option, you are entitled to have a planned caesarean section.

Page last reviewed: 17/07/2014

Next review due: 17/07/2016