An antepartum haemorrhage (APH) is bleeding from the vagina that occurs after the 20th week of pregnancy and before the birth of your baby. The common causes of bleeding during pregnancy are cervical ectropion, vaginal infection, placental edge bleed, placenta praevia or placental abruption.
The cells on the surface of the cervix often change in pregnancy and make the tissue more likely to bleed, particularly after sex. This is called cervical ectropion. This condition does not affect the pregnancy at all. If there is bleeding from the cervix it is important to ensure you are up to date with your PAP Smear and it is normal.
Cervical and vaginal infections can also cause a small amount of vaginal bleeding (eg severe Thrush or Chlamydia) and you may be very uncomfortable. It is important to seek treatment from your doctor for these conditions.
Placental Edge Bleed
In the second half of your pregnancy, the lower-half of the uterus begins to stretch and grow. This can lead to the edge of the placenta separating from the wall of the uterus. In most cases bleeding will stop after a few hours, and your baby will not be adversely affected. However it is important that you contact the hospital immediately if you notice any bleeding.
Placenta praevia is diagnosed when the placenta grows in the lower part of the uterus and is located near to or actually covering the cervix. We classify placenta praevia into four types:
- Type I: the placenta is located in the lower part of the uterus but does not come close to the cervix. You can usually expect to birth vaginally with this type.
- Type II or marginal: the placenta touches but does not cover the cervix.
- Type III or partial: the placenta partially covers the cervix
- Type IV or complete: the placenta completely covers the cervix
Types II, III and IV are associated with a risk of heavy bleeding in labour as the cervix dilates and, therefore caesarean birth is usually recommended.
Causes of placenta praevia
The cause of placenta praevia is often unknown but these are some of the factors that put women more at risk:
- previous caesarean birth or uterine surgery
- previous placenta praevia
- age—above 35 years
- multiple pregnancy—twins or triplets etc
- multiple previous pregnancies
- closely spaced pregnancies
- placental abnormalities
- abnormalities in the baby
As part of the morphology ultrasound scan (USS) at 18 to 20 weeks the site of the placenta is identified. Approximately one in five women will have a low-lying placenta at this time. A repeat USS will be recommended between 32 and 36 weeks of pregnancy depending on where the placenta is positioned at the earlier scan. By this time only 2 per cent of women will still have a low-lying placenta. Your doctor will discuss ongoing management and care. Most women with Type II, III & IV placenta praevia will need to give birth by caesarean section.
Placental abruption occurs when part of the placenta separates from the wall of the uterus prior to term. A large amount of vaginal blood loss usually occurs. Some of the blood may however remain in the uterus and this can lead to a blood clot forming behind the placenta. The amount of vaginal blood loss seen is therefore, not an accurate measurement of the total amount of blood loss which has occurred.
If you have any blood loss or abdominal pain it is important to contact your midwife/obstetrician immediately. Some causes of vaginal bleeding are more serious than others so it is important to find out the reason as soon as possible.
You may be admitted to hospital for observation and assessment of the cause of your bleeding. You will have an ultrasound scan and your baby may have a cardiotocograph (CTG) which checks your baby's heart beat. Depending on how much bleeding has occurred, you may need to have an intravenous (IV) drip inserted and may require IV fluids. In severe circumstances you may require a blood transfusion or your baby may need to be born early. Initially you will be encouraged to rest in bed.
At this point in time, we recommend that you:
- change sanitary pads at least every four hours while you have any blood loss (personal hygiene is very important to reduce the risk of infection)
- do not use tampons
- wipe from front to back after going to the toilet
- do not go swimming
- do not have baths or use a spa—please shower
- do not have sexual intercourse
- do not use any vaginal medications/creams.
If you experience an increase in vaginal bleeding, or abdominal pain or contractions it is important to notify the midwives or doctors as soon as it occurs.
If you have any bleeding in pregnancy there is an increased risk of your baby's blood crossing into your blood stream. If you have a rhesus negative blood group you will be offered an injection of Anti-D immunoglobulin. THis should be discussed with your doctor.
We recommend you discuss the plans for the rest of your pregnancy with your doctor. Please ring Mater Mothers' Hospitals Birth Suites for advice at any time on 07 3163 1918.
Mater acknowledges consumer consultation in the development of this patient information.
Mater Doc Num: HOSP-011-00128
Last modified 16/11/2015.