Placenta Previa Pathophysiology Diagnosis

With the range of complications that can occur during pregnancy, it is amazing anything goes right. One of the major complications that may arise during pregnancy is bleeding. Most of those bleeding disorders arise directly from the placenta and attachment issues. Placenta previa, though rare, is one complication that can occur easily. There are symptoms that allow early detection, diagnostics to confirm the condition, complications that can occur and treatments that can save the life of both the baby and the mother.

Pathophysiology

• The placenta is attached to the uterine wall and connects the baby's blood supply to the mother so it can obtain nutrients and oxygen to grow. In normal cases, the placenta attaches to the upper, back inner wall of the uterus. However, in placenta previa, the placenta attaches in the lower half of the uterus, and lies below the baby. Placenta previa has no preventative measures and occurs in 1 percent or less of all pregnancies. Women who are at risk for this condition are at least 35 years of age, have a history of smoking, have had multiple previous child births (especially c-sections), currently have a multi-fetal pregnancy, a history of placenta previa in other pregnancies and have undergone medical abortions. There are three types of placenta previa: marginal, which lies near the cervix; partial, which partially covers the cervix; and complete, which completely covers the cervix.

Signs and Symptoms

• Despite common assumptions about placenta previa, the condition is usually painless and does not directly lead to uterine contractions, however, they do occur in rare cases. The cardinal sign of placenta previa is spotting or bleeding that is bright red in color. This bleeding can occur at any time but is most common during periods of exercise or strenuous activity. However, this spotting is sometimes confused by women to be the bloody show, or bleeding that occurs during labor.

Resulting Complications

• The most recognized complication that occurs with placenta previa, if not treated correctly, is significant maternal blood loss. However, another complication that can occur in regards to the baby is known as intra uterine growth retardation (IUGR). This problem of delayed fetal growth is caused by a lack of nutrients absorbed by the placenta because of its location.

Diagnostics

• Placenta previa can be diagnosed three ways. The first is through ultrasound or MRI, where the physician can detect the position of the placenta and if it covers the cervical opening. The physician may check certain blood tests to determine if the mother is anemic, or has a low blood count. Finally, the physician may perform a double set-up exam if the maternal bleeding is extensive and there is no time for an ultrasound or MRI. He will examine the cervix by way of a speculum, an instrument that opens the vagina to easily view the cervix. The procedure is performed in an operating room in case an emergency cesarian section is needed.

Treatment and Interventions

• A physician can take many routes when it comes to treating a patient with placenta previa. Based on blood tests and how much blood the mother has lost, the doctor will decide whether or not a blood transfusion is needed. If the bleeding is significant, but not severe enough for a blood transfusion, an iron supplement may be prescribed. If the mother has several cases of bleeding before 37 weeks of gestation, she may be put on bed rest, have to undergo ultrasounds every month (along with other tests to ensure the wellness of the baby), or she may even be admitted to the hospital just in case complications arise. Sometimes, the physician will prescribe medications to stop uterine contractions that may cause the bleeding. If the baby is mature enough, the mother will be induced and deliver vaginally if the previa is marginal. If the previa is complete, the only way to safely deliver the baby is through cesarian section.