What is an abnormally invasive placenta (also called placenta accreta)?
Placenta accreta is a rare (between 1 in 300 and 1 in 2000) complication of pregnancy. This is when
the placenta grows into the muscle of the uterus, making delivery of the placenta at the time of birth
very difficult.
Placenta accreta is more common in women with placenta praevia who have previously had one or more
caesarean births, but it can also occur if you have had other surgery to your uterus, or if you have a uterine
abnormality such as fibroids or a bicornuate uterus. It is more common if you are older (over 35 years old)
or if you have had fertility treatment, especially in vitro fertilisation (IVF).
Placenta accreta may be suspected during the ultrasound scans that you will have in your pregnancy.
Additional tests such as magnetic resonance imaging (MRI) scans may help with the diagnosis, but your
doctor will only be able to confirm that you have this condition at the time of your caesarean.
If you have placenta accreta, there may be bleeding when an attempt is made to deliver your placenta after
your baby has been born. The bleeding can be heavy and you may require a hysterectomy to stop the
bleeding. There is a risk of injury to your bladder during the delivery of your placenta, which depends on
your individual circumstances.
If placenta accreta is suspected before your baby is born, your doctor will discuss your options and the extra
care that you will need at the time of birth. It may be planned for you to have your baby early, between 35
and 37 weeks of pregnancy, depending on your individual circumstances. You may need to wait in hospital for a time before your planned delivery date which would be by planned caesarean section, which would be performed by senior surgeons and anaesthetists.

You will have your baby in a hospital with specialist facilities available and a team with experience of caring for women with this condition.
Your team may discuss with you the option of a planned caesarean hysterectomy (removal of your uterus
with the placenta still in place, straight after your baby is born) if placenta accreta is confirmed at delivery.
It may be possible to leave the placenta in place after birth, to allow it to absorb over several weeks or
months. Unfortunately, this type of treatment is often not successful and can be associated with very
serious complications such as bleeding and infection. Some women will still go on to need a hysterectomy.
Your healthcare team will discuss a specific plan of care with you depending on your individual situation.