When you first talk about a VBAC, the word “risk” is often mentioned. Basically, this means the “chance” of something happening. With a VBAC, there are two main things that health professionals may worry about:
- The placenta can stick to the old scar and grow into it – this is called Placenta Accreta.
The risk (or chance) of this happening have been reported to be as high as 1:300 and as low as 1:2000 pregnancies. The condition is more common in women with a previous caesarean section or uterine surgery. The main problem with this condition is haemorrhage, which can occur during pregnancy or during labour. Average blood loss is between 2 litres and 7.8 litres. This can be fatal. For this reason, all women who have a low, anterior placenta who had a caesarean section previously, are advised to have a detailed scan in a specialist facility to look at the placenta, how it is attached and how it is growing. This may include MRI imaging.
- The old scar can rupture.
The chance of the scar rupturing is low. Some things make this more likely to happen, for example, if you are over 40yrs old, had a baby within the last 12 months, pregnancy is very overdue, baby is very large, or you have a high BMI. Induction or labour also increases the risk. If the scar does rupture, it can be life threatening for mum and baby.