Antepartum hemorrhage is defined as bleeding from the genital tract between the period of fetal viability to the onset of labor. Traditionally the period is taken from 28 weeks onwards. However, with the now-accepted period of viability starting at 22 weeks, the definition has been changed accordingly. Any bleeding that occurs before the period is usually because of some form of abortion. Because it is an important contributor to both perinatal and maternal deaths in any country, it is very important that one has a good grasp of the principles of its management.
The major causes for the hemorrhage are placenta previa and abruptio placenta. A third but less common condition is of the indeterminate type, a diagnosis made by exclusion of the former two conditions. Lastly, the bleeding may come from a local cause in the genital tract such as cervical growth of cervical polyp. In placenta previa, the bleeding results from the separation of a predominantly maternal although a small contribution comes from the fetal side. In abruptio placenta, the bleeding results also form separation of the placenta but in this case, the placenta is normally placed. The blood may also seep into the uterine muscle to give a typical bluish color sometimes describe as Couvelaire uterus. Bleeding from an abruptio placenta is sometimes called ‘accidental’ hemorrhages as opposed to the ‘inevitable’ hemorrhage from a placenta previa.
The amount of bleeding with which the patient presents can vary substantially. It can range from a mere spotting to a ‘torrential’ bleed that becomes life threatening. Whatever the amount, the price must be seen at a hospital with adequate facilities to deal with it. This includes the presence of adequate blood transfusion services and facilities to do an emergency caesarean section.
On admission, a quick assessment is made of her general condition and the vital signs noted. If she is in circulatory collapse, she must first be resuscitated. If, or once her condition is stable, a history and physical examination should be directed towards excluding a diagnosis of placenta previa or abruptio placenta. Predisposing conditions for a placenta previa are multiparity, multiple pregnancies or a previous caesarean section. The predisposing conditions for abruptio placenta on the other hand, include multiparity, hypertensive disorders, trauma to the maternal abdomen or rarely, a sudden release of liquor in polyhydramnios, for example, at amniotomy.
In placenta previa, the abdomen is usually soft, non-tender and the fetal parts are easily felt. A malpresentation of the fetus such as transverse or oblique lie should alert one to the diagnosis. In abruptio placentae on the other hand, the abdomen is tense and tender, sometimes described in the textbooks as ‘woody hard’. The uterus is usually larger than the period of gestation and the fetal parts are difficult to feel because of the tense abdomen. The fetal heartbeat is difficult to hear. If it is absent, the fetus may be dead.
An ultrasound examination of the abdomen is indispensable in coming to a proper diagnosis. The diagnosis of placenta is usually simple. At the time of examination, the type of the placenta previa must be documented. In type 1 and 2, the edge of the placenta, through encroaching on the lower segment, does not cover the cervical os. For this reason, they are called minor previa. In Type 3 and Type 4, termed major previa, the placenta covers the cervical os, and in Type 4, even at full dilatation of the cervix. In abruptio placenta is normally situated. The presence of a retro-placental clot may or may not be seen depending on its size.
Once a diagnosis of placenta previa or abruptio placenta has been excluded, only then should a speculum examination be done to inspect the vagina and cervix. It must be reemphasized that to effectively exclude latter two diagnoses, both a physical examination and an ultrasound examination must be done. At speculum examination, the diagnosis of any local lesions must be excluded, the commonest being, a cervical polyp or a growth on the cervix. If no local lesions can be seen, the diagnosis of the hemorrhage said to be if the indeterminate type. In most cases, it represents a minor abruption that is not clinically evident.
List of Sources:
1. M, “Placenta Previa in Pregnancy”, Associated Content.
2. Kenny Ren, “Abortion: Right or Wrong?”, Associated Content.
3. Alyson Creek, “Abruption Placentae”, Associated Content.
4. James Whistler, “Emergency Vs Elective Caesarian Section: Not Everything is Good, Not Everything is Bad”, Associated Content.
