When is a Caesarean Section Necessary? Key Medical Reasons Explained

Caesarean sections occur in roughly 1 in 3 births in the UK. Figures released by the National Maternity and Perinatal Audit showed that there were 38.9% of births by caesarean section in England, Scotland and Wales in 2023. This figure is up from 25% in 2015–16, examining close to 600,000 births in total. It’s a huge jump and begs the question that pregnant women are asking every day, when is a caesarean section necessary, and what makes it the best option for you and your baby?

In this guide, we’ll run through some of the medical reasons why you may be advised to have a caesarean section, the evidence behind them, and what to expect.

What Is a Caesarean Section?

A caesarean section is where a baby is delivered via an incision through the abdomen and uterus. A caesarean section may be planned ("elective" or "pre-labour") or can be carried out as an emergency procedure during or after labour.

Recent (2023) NHS figures show that nationally, there were 16% elective caesarean sections and 22% emergency caesarean sections. This split is important as the reasons for each, the risk profiles and planned preparation for each are very different.

NICE has published guideline NG192: caesarean birth and VBAC. When to offer or recommend. It summarises the evidence about when to offer and discuss caesarean birth, the procedure itself and after care with the goal of improving consistency and quality of care for women who have or may have a caesarean birth.

Medical Reasons Why a Caesarean Section May Be Necessary

1. Breech Presentation

A baby is in the breech position when it is positioned feet- or bottom-first rather than head-down as the due date approaches. While some babies turn on their own before 37 weeks, others do not.

NICE recommends offering women with an uncomplicated singleton breech pregnancy after 36 weeks external cephalic version (ECV) a procedure to manually turn the baby unless certain contraindications apply. Where ECV is contraindicated or unsuccessful, a caesarean is offered, as it reduces perinatal and neonatal risk.

2. Placenta Praevia

Placenta praevia occurs when the placenta partially or fully covers the cervix, blocking the baby's exit route. Attempting a vaginal birth in this situation risks severe bleeding for both mother and baby.

NICE guidance is clear: caesarean birth should be offered to women whose placenta partly or completely covers the internal cervical os, whether minor or major placenta praevia.

3. Placenta Accreta Spectrum

This is a more complex condition where the placenta attaches too deeply into the uterine wall. It carries a high risk of life-threatening haemorrhage and requires specialist care.

If placenta praevia is identified in a woman with a previous caesarean scar, NICE recommends an ultrasound scan with colour Doppler around 28 weeks to assess for placenta accreta, carried out by a senior clinician with relevant expertise. Confirmed cases are referred to a specialist placenta accreta spectrum centre.

At myGynaePlus, high-resolution ultrasound scanning is a core part of the obstetric care offered, which plays a direct role in identifying complications like placenta praevia early in pregnancy.

4. Fetal Distress During Labour

When monitoring shows that a baby is not tolerating labour well, an emergency caesarean may be the only safe option. Signs of fetal distress include abnormal heart rate patterns detected on a cardiotocograph (CTG), suggesting insufficient oxygen supply.

NICE's quality standard for planned caesarean birth acknowledges that maternal or fetal indications including intrauterine or fetal growth restriction can make earlier delivery necessary, even before the standard planned timing of 39 weeks.

5. Failure to Progress in Labour

Labour that stalls where the cervix stops dilating despite regular contractions can become a reason for caesarean section, particularly if other interventions such as augmentation with oxytocin have not worked. This is one of the more common indications for emergency caesarean birth.

NICE recommends using a partogram with a four-hour action line to monitor progress during spontaneous labour, as this reduces the likelihood of caesarean birth. When progress still fails despite active management, surgical delivery becomes the safer choice.

6. Pre-eclampsia and Hypertensive Disorders

Severe pre-eclampsia, which is high blood pressure with organ involvement, can progress quickly. Delivery is the only treatment that can cure the patient. Depending on how far along you are and how stable you are clinically, you might need to have a caesarean.

Hypertensive disease is just one of the maternal indications or fetal indications where NICE says earlier planned caesarean birth may be required.

7. Multiple Pregnancy

Twin and higher-order multiple pregnancies carry elevated risks during labour, including cord prolapse and abnormal presentation of the second twin. The mode of birth for twins depends on the position of the presenting twin, chorionicity, and gestational age. For triplets and higher multiples, caesarean birth is often recommended as standard practice.

8. Previous Caesarean Section

Women who have had a prior caesarean face a choice between vaginal birth after caesarean (VBAC) and a repeat elective caesarean. The main concern with VBAC is the risk of uterine rupture at the site of the previous scar.

Research published in the BMJ found that women who had previously had a caesarean were much more likely to have another one, with 70.8% of those with a prior caesarean delivering by caesarean again. The decision requires careful discussion with an obstetrician, taking into account the reason for the first caesarean, the interval between pregnancies, and the woman's own preferences.

9. Cord Prolapse

When the umbilical cord slips through the cervix ahead of the baby, it can become compressed, cutting off the baby's oxygen supply. This is a genuine obstetric emergency and almost always requires immediate caesarean delivery.

10. Maternal Health Conditions

Specific pre-existing conditions may render vaginal birth medically contra-indicated. Some cardiac conditions, genital herpes active at the onset of labour (for which you have not received antiviral suppression), certain neurological conditions and HIV (in certain circumstances) fall under this category. Each case is taken on its own merits by the obstetric team.

Planned vs Emergency Caesarean: What's the Difference?

• Planned (elective) caesarean: Scheduled before labour begins, usually from 39 weeks onwards, based on a known clinical indication or in some cases at the mother's informed request.

• Emergency caesarean: Performed when an unexpected complication arises during pregnancy or labour. The urgency varies; not all emergency caesareans are immediate crises. NICE uses a four-category classification system to indicate how quickly the operation needs to happen.

Planned caesarean birth should not routinely be carried out before 39 weeks, as babies born before this point face a higher risk of respiratory complications. That risk decreases meaningfully from 39 weeks onwards.

When Can a Caesarean Be Requested Without a Medical Reason?

NICE guidance says that 'If she requests a caesarean section and has severe anxiety about childbirth, including tokophobia or a history of trauma or abuse, she should be offered referral to a healthcare professional who can assess and provide support relating to her perinatal mental health. 

If she does not want a vaginal birth after receiving full counselling about all her options, a planned caesarean section can be offered. "In all areas, the key principle is that women should be able to make an informed decision. They should be given information about the benefits and risks of each option so they can choose what is right for them.

What Are the Risks of Caesarean Section?

A caesarean section is major surgery. It carries risks that increase with each subsequent procedure.

Short-term risks for the mother include:

• Wound or uterine infection

• Excessive bleeding (haemorrhage)

• Deep vein thrombosis (DVT)

• Bladder or ureter injury

The Lancet Series on Optimising Caesarean Use notes that both for the mother and for future babies, the risk of harm increases with every pregnancy after the first caesarean section.

For babies, risks include transient respiratory difficulties and, occasionally, a minor skin cut during the procedure. These are usually mild and resolve quickly.

The team at myGynaePlus provides personalised obstetric consultations that help women understand these risks in the context of their own health, so they can make genuinely informed choices about their birth plan.

Caesarean Section Recovery: What to Expect

Convalescence from a caesarean is longer than from an uncomplicated vaginal delivery. Length of hospital stay varies, but is usually two to three days. Complete caesarean section recovery usually occurs within six to eight weeks, during which lifting, driving and strenuous exertion are discouraged. 

Pain relief, wound care, thromboprophylaxis (prevention of thrombosis) and early mobilisation are all aspects of routine postoperative care. Early skin-to-skin contact with the newborn is promoted if mother and baby are stable.

Final Thoughts

Knowing why you need a caesarean places the decision squarely into perspective – it’s no longer some abstract idea but a discussion you have with your care team. Whether it’s planned due to an identified complication or an emergency procedure required during labour, the reasons will always be the same, ensuring a safe outcome for mother and baby.

If you’re planning a pregnancy or are expecting and want specialist advice on your birthing options, visit myGynaePlus for all your obstetric needs. We offer early pregnancy scans, consultant led appointments and birth planning all under one roof in West London. Book now!

FAQs

Q: Is a caesarean section safer than vaginal birth? 

A caesarean is not inherently safer than vaginal birth. It is a major operation with its own risks. Whether it is the right choice depends on your specific clinical situation. NICE recommends weighing the benefits and risks of both options in each individual case, rather than assuming one is always better.

Q: Can I request a caesarean if I am anxious about labour? 

Yes. NICE guidance states that women with severe anxiety about childbirth, including those with tokophobia or a history of trauma, should be offered mental health support. If, after counselling, vaginal birth remains unacceptable, a planned caesarean can be arranged. Speak to your obstetric team.

Q: How many caesareans can you safely have? 

There is no set upper limit, but risk increases with each procedure due to scar tissue formation and complications like placenta accreta. Most obstetricians discuss the risks carefully after a second or third caesarean. Each pregnancy is reviewed individually.

Q: Will I need a caesarean in future pregnancies if I have one now? 

Not automatically. Many women go on to have a successful vaginal birth after caesarean (VBAC). Whether this is appropriate depends on the reason for your previous caesarean, how your uterine scar has healed, and your own preferences. Your consultant will advise you.

Q: When should a planned caesarean take place? 

NICE recommends that planned caesarean birth should not be scheduled before 39 weeks unless a maternal or fetal indication makes earlier delivery necessary. Delivering at 39 weeks or later reduces the risk of respiratory complications for the baby.