Vaginal birth after caesarean section

If you have previously given birth by caesarean section your care will differ slightly. You will continue seeing your midwife in the community setting, but will also be invited for a consultant appointment at 14 to 16 weeks and then again at 34 to 36 weeks.  A full discussion about your previous birth and current pregnancy will take place and the options for birth this time around.  Your consultant should go through the risks and benefits of both a VBAC (vaginal birth after caesarean) and an EL LSCS (elective caesarean section).  If you decide to opt for an EL LSCS then your surgery will be booked in when you have your 34 to 36 week appointment.

What is our guideline on VBAC?

Please be mindful that although this is our hospital guideline it doesn’t mean you have to follow it.  Your birth preferences should always be taken into account and your birth plan should always be individualised.

You are advised to ring triage when you think you might be in labour – when contractions start, when your waters break, if you have any blood loss, or if you have any scar pain (scar pain can be felt between contractions as well as within).

Once you come into triage the midwife will carry out a full assessment, including taking your observations, monitoring baby on a CTG monitor and offering you a vaginal examination if you are having regular, strong contractions.  The obstetrician will also come and see you and talk about your plan for labour.  If you are in established labour (4cm or more and contracting regularly) then you will go to delivery suite for one to one care.  If you are in the earlier stages of labour you will be advised to stay in on the maternity ward.

Once on delivery suite, it will be advised that you have continuous monitoring of your baby.  If available we can offer you wireless monitoring to enable you to remain mobile and encourage the progression of labour.  You will still have the option of using water for your labour if the contact with baby’s heartrate is able to be maintained.

It will be advised that an IV cannula is sited and some blood samples taken in case at any point there is a need to move to theatre.

All forms of pain relief are available to you, including an epidural.  It has been found that scar pain can still be felt with the use of epidural.

When you come to the 2^nd stage of labour (pushing), it is advised that after an hour the obstetrician comes to review how progress is going.  It is advised that pushing doesn’t go over two hours due to the pressure on your scar. 

Evidence surrounding VBAC

When deciding whether to have a VBAC, the main concern you will hear and read about is uterine rupture.  This is when the scar on your uterus opens.  Below are the statistics of this happening.

Risk of uterine rupture

• Uterine rupture in women who had not had a previous caesarean section: 0.03%
• Uterine rupture in women who had had a previous caesarean section: 0.22%
• A difference of 0.19%

These statistics are based on a study involving the review of 2,625,017 births from 2004 to 2014 (Vandenberghe et al, 2019).

However, statistics vary depending on the length of time between the previous caesarean section and the next pregnancy.

One study showed that:

For women with less than six months between CS and pregnancy the rate of uterine rupture the risk was 2.7%.

For women with more than a six month interval, the risk of uterine rupture was 0.9% (Stamilio, 2007).

However, another study found no significant difference in the rate of rupture with shorter interpregnancy intervals. (Rietveld et al, 2017).

What are the repercussions of a uterine rupture?

Of the women who had a uterine rupture (0.03% and 0.22%) from the above study, the following was found:

• 21% of women needed 4 units of red blood cells infused
• 20% of women were admitted to intensive care
• 10% of women had a hysterectomy
• 0.002% of women died
• 7.7% of babies were temporarily deprived of oxygen
• 10% of babies died 

How do you know if a uterine rupture is happening?

The main signs and symptoms of a uterine rupture are:

• A fetal heart rate abnormality
• Abdominal pain
• Vaginal bleeding

A fetal heart rate abnormality is picked up in 46% to 78% of uterine ruptures when using continuous monitoring (CTG monitoring).

Abdominal pain is reported in 25% to 28% of uterine ruptures.

Vaginal bleeding is evident in 23% to 33% of uterine ruptures.

(Guiliano et al 2014, Chang et al, 2020)

Risks associated with an elective/emergency caesarean section

The Royal College of Obstetricians and Gynaecologists (RCOG) outline the risks associated with caesarean section:

• Hysterectomy (removal of uterus) 0.07%
• The need for further surgery: 0.05%
• Being admitted to intensive care 0.09%
• Thromboembolic disease (blood clot) 0.04-0.16%
• Injury to the bladder 0.01%
• Injury to the ureter (the tubes which carry urine from the kidneys to the bladder):               0.03%
• Increased risk of uterine rupture in future pregnancies/births: 0.02-0.07%
• Increased risk of stillbirth in future pregnancies: 0.01-0.04%
• Increased risk of low lying placenta and placental accrete in future pregnancies:                   0.04-0.08%
• Persistent wound and abdominal discomfort in first few months after birth: 0.09%
• Increased chance of repeat CS in future pregnancy: 25%
• Being readmitted to hospital: 5%
• Haemorrhage: 5%
• Infection: 6%
• Baby is cut during surgery: 1-2%

RCOG also note that there can be complications for babies after a caesarean section, such as respiratory distress syndrome, pulmonary hypertension, iatrogenic prematurity, difficulty with bonding and breastfeeding.

References

(Vandenberghe et al, 2019 The International Network of Obstetric Survey Systems study of uterine rupture: a descriptive multi-country population-based study - PubMed (nih.gov))

(Rietveld et al, 2017: Effect of interpregnancy interval on the success rate of trial of labor after cesarean | Journal of Perinatology (nature.com) 

(Stamilio, 2007: Short interpregnancy interval: risk of uterine rupture and complications of vaginal birth after cesarean delivery - PubMed (nih.gov) 

Guiliano et al 2014 Signs, symptoms and complications of complete and partial uterine ruptures during pregnancy and delivery - PubMed (nih.gov) 

Chang et al, 2020 Uterine rupture over 11 years: A retrospective descriptive study - PubMed (nih.gov)