Antepartum Haemorrhage - Symptoms & Treatment

Before the 24th week of pregnancy any bleeding is, by definition, a threat to miscarry or abort and is known as a threatened abortion. After the 24th week, however, when the child is viable, such bleeding is known as antepartum haemorrhage.

Bright red blood coming after the 24th week of pregnancy should be reported to the doctor-or midwife immediately regardless of the hour of day or night at which it is first noticed. It can easily be distinguished from the small quantity of pinkish or brownish mucus which a woman often passes at the onset of labor. The passage of such a pink mucous plug should not cause any alarm, but if this occurs before the 36rh week of pregnancy, the doctor should be notified.

An antepartum haemorrhage may fall into one of three main categories:

Placenta praevia is a condition in which the placenta, instead of being attached to the upper part of the uterus, is attached to the lower part in the region of the lower uterine segment or the cervix.

Accidental antepartum haemorrhage (abruptio placentae) is a comparatively rare condition in which the placenta is normally Implanted In the upper part of the uterus but detaches from it prematurely and usually results in bleeding.

Incidental antepartum haetnorrhage is haemorrhage which occurs from the genital tract but not from the site of the placenta or its implantation. Such haemorrhage may result from injury, infection, ulcers on the neck of the womb, polyps or, I1lOstcommonly, the onset of labor.

Placenta praevia

The placenta is normally situated in the upper part of the uterus and usually on the posterior wall. Occasionally probably due to a fault of implantation of the ovum, it is situated in :he lower part of the uterus. and is known ~ placenta praevla. Placenta implanted in the lower uterine segment will be below the baby's head. Changes occur in the lower part of the uterus and the cervix during the last 2 months of pregnancy in preparation for labor. These are mainly stretching of the lower segment with a gradual softening and shortening of the cervix.

The placenta is then inevitably separated to some extent from the uterus. Separation of the placenta always results in bleeding. It is important to remember that the bleeding which occurs in placenta praevia is the mother's blood and not blood from the baby's circulation. A baby is rarely harmed or injured in any way by what may occasionally seem to be quite a lot of bleeding.

Any bleeding after the 24th week of pregnancy should be reported to the doctor. Bleeding which occurs during the last 2 months of pregnancy is especially significant and the woman is nearly always admitted to hospital until a diagnosis of placenta praevia has been proved, or disproved by ultra-sonic scan. If a diagnosis of placenta praevia is proved, then she will probably have to remain in hospital until delivery. A placenta that is situated over the lower uterine segment will almost certainly cause more bleeding before the onset of labor and will certainly bleed again when labour starts. If the woman is under proper supervision in hospital, any further haemorrhage can be investigated immediately and appropriate steps taken to ensure safe delivery without danger to the mother or her child. In significant degrees of placenta praevia it may be necessary to perform Caesarean section. In mild degrees of placenta praevia normal labor is allowed to proceed but the membranes may be artificially ruptured shortly after the onset of labour.

The exact cause of placenta praevia is not known. It is very rare in first pregnancies and becomes more frequent with each subsequent pregnancy. Even so, it still remains a relatively uncommon condition only occurring about once in every 100-200 pregnancies.