Placenta praevia is a complication that can happen during pregnancy. It's also called low-lying placenta (afterbirth). It is not common.
Placenta praevia happens when the placenta:
- lies over the cervix (the neck of your womb)
- is in the lower part of the womb
This can lead to heavy bleeding in pregnancy or during childbirth.
If you have placenta praevia, you will have extra scans. Some people may need to have a caesarean birth.
Urgent advice: Contact your maternity unit or hospital immediately if
you have been told you have placenta praevia and have:
- any vaginal bleeding
- tummy pain
- contractions
How you know the position of the placenta
The position of the placenta is recorded during your fetal anatomy scan. This is an ultrasound scan you have at 18 to 22 weeks.
If you have a low-lying placenta, you will have a follow-up scan in the third trimester. This is to check if your placenta has moved.
For 9 in 10 women with a low-lying placenta, the placenta moves up in the womb by the third trimester and does not affect the birth.
If the placenta is still low or over the cervix in the third trimester, this is called a placenta praevia.
Placenta praevia in the third trimester happens in 1 in 200 pregnancies.
Signs and symptoms of placenta praevia
Placenta praevia usually does not cause any symptoms.
But if you do have symptoms or signs, they include:
- vaginal bleeding in the second or third trimester, or after sex
- your baby lying in an unusual position - such as breech presentation or sideways across the womb (transverse lie)
Any bleeding is usually painless but it may be heavy. Bleeding could put you or your baby at risk.
You may have an internal scan to check for placenta praevia if you develop signs and symptoms later in pregnancy. This is to check the distance of the placenta from the entrance to the cervix.
Urgent advice: Contact your GP, midwife or obstetrician immediately if:
- you have any bleeding during pregnancy
If you have placenta praevia
If you have placenta praevia, you need to take extra care during your pregnancy.
You may need to:
- have extra ultrasound scans to check the position of your placenta
- avoid sex to prevent more bleeding
- take an iron supplement - this is to reduce the risk of you becoming anaemic and build up your iron levels
Early hospital admission
At week 34 of your pregnancy, you may need to go into hospital until you give birth. This is so you can get treatment immediately if you need it. If you have repeated bleeding, you may need to stay in hospital earlier.
You may also have steroid injections. This helps your baby's lungs to develop in case they need to be delivered early.
Blood transfusions
You may need blood transfusions if you have heavy bleeding during your pregnancy or the birth.
Tell your obstetrician or midwife if you want to refuse treatment with blood or blood products for religious or cultural reasons. They can put this in your notes early in your pregnancy.
Caesarean birth
You may need a caesarean section if:
- the placenta blocks your baby’s way out through the birth canal
- you or your baby are at risk
- you have heavy bleeding
- the placenta remains low around 37 weeks
- labour starts prematurely
Your doctor may plan a caesarean birth for around 37 to 38 weeks. This is because of the risk of bleeding.
Premature birth
If your baby is born prematurely, they may need extra care after the birth. For example, in a special baby unit or neonatal intensive care unit.
They may need to go to another hospital that has facilities to care for premature babies. If this happens, a specialist team will transfer your baby.
