A subchorionic hematoma is a fairly common complication of pregnancy that involves blood entering and clotting in the space in between the placenta and the uterine wall. Bleeding occurs when part of the placenta detaches from the surrounding endometrial tissue in one or more places. In most cases, a small hematoma does not cause any symptoms nor is it a reason for major concern. A large one, however, can cause abdominal pains in the mother and unusual vaginal bleeding during pregnancy. There is a risk of miscarriage when symptoms are present, but careful monitoring, bed rest, and medication can greatly reduce the chances of complications.
The causes of a subchorionic hematoma are not entirely known. Problems occur when the outermost layer of the placenta, called the chorionic membrane, separates slightly from the uterine wall. This separation typically happens in the first trimester or early in the second trimester of pregnancy. There is no evidence to suggest that an expecting mother's genetics, diet, age, or activities have anything to do with the issue.
When hematoma occurs, blood pools in front of the uterine wall and gradually seeps into the underlying endometrial tissue. If there is a large amount of blood, a woman may experience spotting or occasionally heavy bleeding from her vagina. Clotting occurs as more blood is released, which can lead to cramps, bloating, and general abdominal pains. A large number of patients who have such hematomas do not experience any unusual physical symptoms.
A subchorionic hematoma can usually be diagnosed with a simple ultrasound scan. Radiologists can easily tell where blood is collecting, how much is present, and whether or not the placenta or uterus has been damaged by studying ultrasound images. Once a diagnosis has been made, a medical professional can explain the details and risks of the situation to the patient and answer questions she may have. The prognosis is very good for most expecting mothers and their babies, especially if clots are small and there are no major symptoms.
Most obstetricians recommend their patients get plenty of rest and avoid stressful activities once they are diagnosed with subchorionic hematomas. They need to attend regular checkups so the healthcare provider can see whether internal bleeding is improving or getting worse. In some cases, a medical professional may recommend taking low-dose blood thinners to prevent clotting and expel pooled blood more quickly. Most hematomas gradually dissipate over several weeks, and mothers are able to reach full-term without further problems.