Excessive loss of blood immediately after delivery of a baby or in the first few weeks following childbirth
- More common over the age of 35
- Genetics and lifestyle are not significant factors
Almost all women have some degree of blood loss over the 3 or 4 days after childbirth, and most women have some light vaginal bleeding for up to 4 weeks afterwards. Postpartum haemorrhage is defined as the loss of more than 500 ml (1 pint) of blood after childbirth.
After delivery of the baby, the placenta normally separates from the wall of the uterus and is then expelled from the body through the vagina. The site where the placenta was attached continues to bleed until strong contractions of the uterus constrict the blood vessels in the wall of the uterus and gradually stop the flow of blood. The majority of postpartum haemorrhages, especially if severe, are the result of bleeding from the uterus. However, bleeding may also come from the cervix or the vagina.
Postpartum haemorrhage occurs in about 1 in 50 births, usually immediately after delivery (early postpartum haemorrhage). Only a few women have a late postpartum haemorrhage, in which excessive bleeding occurs more than 24 hours after delivery. Severe postpartum haemorrhage may be life-threatening, but is uncommon.
What are the causes?
In most cases, early postpartum haemorrhage occurs because the uterus is unable to contract sufficiently to constrict the blood vessels in its wall. This may be due to exhaustion of the muscles of the uterus after a prolonged labour, overstretching of the uterus as a result of a multiple pregnancy (see Multiple pregnancy and its problems), excess amniotic fluid (see Polyhydramnios), or a large baby.
Contraction of the uterus may also be impaired by noncancerous growths in the uterus (see Fibroids) or if some or all of the placenta remains in the uterus after birth. Occasionally, a general anaesthetic given for a caesarean section can impair contractions. Early postpartum haemorrhage may also occur if the placenta has implanted in the lower uterus (see Placenta praevia).
Less commonly, a tear in the cervix or vagina during childbirth may cause early postpartum haemorrhage. Such tears are more likely to occur if the baby is born rapidly, is not born head first (see Abnormal presentation), or is delivered with forceps or suction (see Assisted delivery).
Late postpartum haemorrhage is usually caused by fragments of the placenta left in the uterus or by an infection.
What are the symptoms?
The main symptom of early postpartum haemorrhage is excessive loss of bright red blood through the vagina after birth.
A late postpartum haemorrhage may occur between 24 hours and 6 weeks after the birth. Symptoms may include:
Sudden, heavy vaginal bleeding that is bright red in colour.
Lower abdominal pain.
Sudden, severe loss of blood may lead to shock. Early postpartum haemorrhage almost always occurs while you are hospitalized. If you are not in hospital and develop severe bleeding through the vagina after giving birth, you should seek medical advice immediately.
How is it diagnosed?
If you are not already in hospital, you will probably be admitted immediately. Your pulse and blood pressure will be monitored to look for any evidence of shock. If an early postpartum haemorrhage has occurred, your doctor will feel your lower abdomen to see if the uterus is contracted. The placenta will be checked to ensure that it is complete. If the uterus appears to be contracted but bleeding continues, your cervix and vagina will be examined. This may be carried out under general anaesthesia or epidural anaesthesia.
If you are having a late postpartum haemorrhage, your doctor may arrange for an ultrasound scan, using a probe inserted into the vagina, to check for remaining pieces of placenta in the uterus. A vaginal swab may be taken to check for evidence of infection.
What is the treatment?
If an early postpartum haemorrhage is due to poor contraction of the uterus, you may be given an injection to help the uterus to contract. Your doctor may also massage your abdomen. If these measures do not work, further drugs may be given to help the uterus to contract. If the bleeding continues, surgery may be required. In rare cases, a hysterectomy may be necessary. Bleeding caused by a retained placenta is treated by manually removing the remaining placenta through the vagina. If the blood loss is due to tears in the cervix or vagina, these will be stitched.
If a late postpartum haemorrhage is the result of an infection, antibiotics will be prescribed. If the bleeding continues, surgery may be needed to examine the uterus and remove any remaining fragments of placenta. Blood lost due to a postpartum haemorrhage may have to be replaced by a blood transfusion.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.
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