Placenta - What is a Placenta Abruption?

When All Is Not Well With the Placenta

The placenta is the literal lifeblood of the developing baby in the uterus, and if something goes awry with the placenta, the baby's life is in danger. If, as happens sometimes, the placenta peels away from the uterine wall either entirely or partially it is known as placenta abruption - or in Latin, abruptio placentae. When it happens, the baby is deprived of oxygen and the mother bleeds very heavily. If the condition is not treated (it is an emergency situation) then both the lives of mother and child are at risk.

What Causes Placenta Abruption?

The cause of placenta abruption is, in most cases, not known. However, there are some possible explanations, including: a trauma or injury to the abdomen, perhaps from a fall or automobile accident; the umbilical cord is unusually short; or there is a rapid loss of amniotic fluid from the uterus. Without prompt medical attention placental abruption may lead to maternal shock, premature birth, harm to the fetus due to oxygen deprivation which may lead to neurological problems for the baby later on, and in the worst case, stillbirth. The mother may have to have a hysterectomy if the bleeding can't be controlled after the birth of the baby. During the course of pregnancy, an ultrasound will indicate the location of the placenta and the ob-gyn will be able to watch carefully to manage the situation and be alert to any possible emergencies.

When The Placenta Penetrates the Uterine Wall

In a normal pregnancy, the placenta attaches to the uterine wall, which is exactly what it should do. However, there are cases where the placenta attaches to the walls to deeply and depending upon the depth of the attachment, the condition may be called placenta accreta, placenta increta, or placenta percreta. The most common of these three is placenta accreta, when the placenta attaches too deeply but doesn't penetrate the uterine muscle. Placenta increta occurs when the placenta actually does penetrate the uterine muscle and placenta percreta is the condition where the placenta penetrates the uterine muscle and goes entirely through to attach to other organs, like the bladder.

The cause of placenta accreta is not known but it is related to placenta previa and prior cesarean deliveries. What is of primary concern with this condition is the possible complications and risks to the baby. Bleeding during the third trimester may signal placenta accreta and the most common result is a premature delivery. The ob-gyn will examine the condition and use medication, bed rest and whatever else deemed necessary to address it in order to encourage the pregnancy to full term.

Low-Lying Placenta or Placenta Previa

A low-lying placenta may not be a problem and does not necessarily lead to difficulties or complications. This condition is revealed during the ultrasound taken in the fourth or fifth month of pregnancy, when the doctor is not usually too concerned about where the placenta is lying. If the placenta is lying over the cervix, some bright red bleeding may occur, however, it doesn't pose any threat to the baby. In fact, many times the placenta will migrate to the right place during the course of pregnancy as both baby and placenta grow. If the placenta doesn't move and remains over the cervix, then the delivery will be by cesarean rather than vaginally. A low-lying placenta that doesn't move is called placenta previa - it means that the placenta is in front of the cervix rather than on the side or top of where the baby is lying.

If the placenta totally covers the cervix the condition is called a total or complete previa and if it is on the border of the cervix, it is called a marginal previa. The location of the previa will be checked at the four month mark by ultrasound and if it persists rather than moves, a follow-up ultrasound may lead to pelvic rest - one of the basic placenta previa treatments. The idea is to eliminate any provocation for bleeding, which can happen easily with this condition. Placenta previa symptoms are mostly marked by bleeding in the third trimester, when the cervix begins to thin out in preparation for delivering the baby. Placenta previa causes are vague, but there are indicators of risk in some cases. Often, it happens without explanation, however, women who have had it in previous pregnancies may have it again. A cesarean delivery increases the risk and any other type of uterine surgery also increases the possibility of placenta previa. The use of cocaine and cigarette smoking have been linked to this condition as well.