A subchorionic hematoma is one of the common abnormalities that is detected during an ultrasound scan in pregnancy. It is believed that the effect of a hematoma on the pregnancy outcome depends on factors such as the size of the hematoma, age of the expectant mother, and the gestational age.
The amniotic sac, which is commonly referred to as the bag of waters, is a fluid-filled membranous sac that protects the fetus in the uterus. The inner layer that contains the amniotic fluid is referred to as the amnion, whereas the outer membrane is called chorion. This outer membrane is composed of two layers. Chorion and endometrium form the placenta, which supplies oxygenated blood and nutrients to the fetus.
The term 'subchorionic hemorrhage' describes a pregnancy-related condition that is characterized by the development of localized collection of blood between the chorion and the uterine wall. This condition is also called subchorionic hematoma (SCH). It usually occurs within the first 20 weeks of gestation. The exact cause of this medical condition is still unknown. However, some researchers believe that a hematoma might form, if the fertilized egg separates from the uterine wall during the process of implantation.
Symptoms and Diagnosis
Pregnancy is a time when even the slightest fear of complications can cause women to panic. More often than not, pregnant women become anxious on experiencing vaginal bleeding. Vaginal bleeding during the first trimester is a common cause of concern in about 14 to 20% of pregnancies, as this is often associated with complications such as an impending miscarriage or threatened abortion.
Subchorionic hematoma might be observed in approximately 1.3% of all pregnancies, with 20% to 25% of these cases involving women affected by vaginal bleeding. However, every woman affected by SCH is not likely to experience spotting or bleeding. In some cases, SCH might be asymptomatic. Under such circumstances, this condition is more likely to be detected incidentally during an ultrasound examination. However, in some cases, women might experience spotting or bleeding that might range from light or moderate spotting to heavy bleeding with clots. Mild abdominal cramping might be experienced by some women affected by SCH.
Various studies have been conducted to analyze the effect of SCH on obstetric outcome and the specific characteristics of SCH such as the volume/size of the clot, location, and gestational age in case of women affected by vaginal bleeding. It is believed that a small hematoma is a common, insignificant ultrasound finding. If the size of the hematoma is small and it is not placed close to the placenta, the pregnancy is likely to be viable. In such cases, the clot usually regresses or resolves on its own, without any treatment. However, certain studies have revealed the risk of adverse pregnancy outcomes such as placental abruption, preterm birth, or miscarriage.
As the name suggests, this condition is characterized by the partial or total separation of the placenta from the uterine wall before the delivery. This complication occurs in about 1 out of 150 deliveries. Once the placenta gets detached, the supply of oxygen and nutrients to the fetus is interrupted, which can have an adverse effect on the pregnancy.
The term 'preterm birth' refers to the birth of a baby prior to 37 weeks of gestation. A few studies suggest that women with ultrasound-detected subchorionic hemorrhage before 22 weeks of gestation are at a greater risk of preterm delivery.
Women affected by vaginal bleeding and abdominal cramps with a SCH may sometimes receive a diagnosis of threatened miscarriage. The term 'threatened miscarriage' suggests that a miscarriage could take place before the twentieth week of pregnancy. It is believed that women affected by bleeding and a subchorionic hematoma at or before 8 weeks of gestation are more likely to have a miscarriage than those with bleeding after 8 weeks of gestation.
It must be noted that certain studies contradict the aforementioned findings. These studies suggest that an adverse pregnancy outcome should not always be associated with a SCH detected during the first trimester in women with vaginal bleeding.
More often than not, doctors follow a 'wait-and-watch' approach, if SCH is observed during an ultrasound examination. Ideally, such blood clots must resolve before the twentieth week. If the blood clot persists even after the second trimester, then certain self-care measures are suggested to lower the risk of placental abruption. If a pregnant woman experiences abdominal pain, cramps, and vaginal bleeding in the second or third trimester, she must seek medical assistance at the earliest.
The approach for treatment might vary, depending on the size of hematoma. Large-sized hematomas pose a greater risk, which is why closely monitoring the size and changes through ultrasound examinations is integral to the treatment. Generally, women who have large-sized blood clots between placental membranes and uterus are asked to take rest. The self-care measures that are recommended include:
♦ Women must refrain from lifting heavy objects, as that can put pressure on abdominal muscles and pelvic floor muscles, which can increase the risk of bleeding.
♦ They must not indulge in strenuous physical activities.
♦ Rest is advised to prevent an increased heart rate and blood flow.
♦ They must increase their intake of water and fiber to prevent constipation.
In rare cases, doctors might recommend the use of blood thinners to bleed the clot out. However, the use of blood thinners will be suggested after weighing the pros and cons and keeping the overall health of the patient in mind. If the chances of miscarriage are high, doctors might recommend estrogen and progesterone therapy.
Women who have been diagnosed with a subchorionic hemorrhage must follow the aforementioned measures till the bleeding and the associated symptoms resolve. They must religiously follow the advice of their doctor, as studies associate limited physical activity and bed rest with lower risk of pregnancy-related complications in women affected by SCH.
Disclaimer: The information provided in this article is solely for educating the reader. It is not intended to be a substitute for the advice of a medical expert.