Complications that can affect the placenta during pregnancy or childbirth include:
- low-lying placenta
- retained placenta
- placental abruption
These complications are rare.
Low-lying placenta
As your pregnancy progresses, your womb expands and this affects the placenta’s position. The area where the placenta is attached usually stretches upwards, away from your cervix.
If the placenta stays low in your womb, near to or covering your cervix, it may block the baby’s way out. This is called low-lying placenta or placenta praevia. This is a rare complication, and affected 6 in 1,000 NHS hospital births in England during 2008-09.
The position of your placenta will be recorded at your 18-21-week ultrasound scan. If your placenta is significantly low, you’ll be offered an extra ultrasound scan later in your pregnancy (usually at about 32 weeks) to check its position again. For 9 in 10 women, by this time the placenta will have moved into the upper part of the womb.
If the placenta is still low in your womb, there’s a higher chance that you could bleed during your pregnancy or at the time of birth. This bleeding can be very heavy and put you and your baby at risk. You may be advised to come into hospital at the end of your pregnancy, so that emergency treatment can be given very quickly if you bleed.
If the placenta is near or covering the cervix, your baby cannot be delivered through the vagina, so a caesarean section will be recommended.
A low-lying placenta can be associated with painless, bright red bleeding from the vagina during the last three months of pregnancy. If this happens to you, contact your midwife or GP immediately.
Retained placenta
After your baby is born, part of the placenta or membranes can remain in the womb. This is known as retained placenta and happened in about 9 in 1,000 NHS hospital births in England during 2008-09.
Breastfeeding your baby as soon as possible after the birth helps your womb contract and push the placenta out.
Your midwife may also ask you to change the position you are in, for example by moving to a sitting or squatting position.
If these methods don’t work, it may be necessary to remove the placenta under general anaesthetic.
Placental abruption
Placental abruption is a serious condition in which the placenta starts to come away from the inside of the womb wall. It can cause stomach pain, bleeding from the vagina and frequent contractions.
The exact cause of placental abruption is unclear, but factors that increase the risk include injury to the abdominal area, smoking, cocaine use and high blood pressure.
If you’re near your due date, the baby will need to be born straight away, and a caesarean may be recommended. However, if the baby is very premature and the abruption is minor, you may be kept in hospital for close observation.
Always speak to your midwife or GP if you are concerned about any aspect of your health when you are pregnant. You can also call NHS Direct on 0845 4647.
Read the answers to more questions about pregnancy.
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