Subchorionic Hematoma: What It Is, Causes & Pregnancy Risk

Image: Shutterstock

A subchorionic hematoma is a condition where there is abnormal blood accumulation between the uterine wall and the chorionic membrane. It is one of the many underlying causes that may lead to vaginal bleeding during pregnancy. Vagina bleeding at any stage in pregnancy needs immediate medical assessment. In this post, we explain the causes, symptoms, diagnosis, side effects, and treatment of subchorionic hematoma.

In This Article

What Is Subchorionic Hematoma?

Subchorionic hematoma (SCH), also termed as subchorionic hemorrhage, is a condition wherein the blood collects/clots between the uterine wall and the chorionic membrane (1 ). The chorion is the outer membrane between the uterus and placenta, and surrounds the amniotic sacⁱXA sac of fluid that holds the fetus in the uterus. .

Image: Shutterstock

The hematoma leads to placental detachment from the chorion membrane, causing subchorionic bleeding. Around 25% of pregnant women experience subchorionic bleeding during the first trimester (2).

How Common Is Subchorionic Hematoma?

Around 5-25% of pregnant women experience subchorionic hematoma during pregnancy. Vaginal bleeding complicates around 20-25% of all pregnancies, and nearly 20% of pregnant women who visit a hospital with vaginal bleeding are diagnosed with SCH.

Let’s see what leads to SCH and vaginal bleeding.

What Are The Causes Of Subchorionic Hematoma?

The exact cause of SCH is not yet known. It is assumed to be the result of a preexisting autoimmune disease or immunological factors.

Another probable reason is poor placentation, which results in weak vessels that could tear under pressure and lead to low pressure bleeding (3). This condition occurs when the placenta detaches from its plantation site, causing the blood to flow into the chorionic membrane. Thus, a blood clot is formed in the space between the uterus and the placenta (4).

The other causes could be:

Abnormal implantation of the fertilized egg in the uterus
More in pregnancy conceived via IVF or frozen thawed embryo transfer

Trauma

Blood coagulation disorders

Scars from previous dilatation and curettageⁱXThe removal of tissue from inside the uterus with a surgical instrument called a curette.

Mother’s age is more than 35 years

Uterine malformation

Infection

The condition could go unnoticed but for vaginal bleeding.

Quick fact

Women with high blood pressure may be at an increased risk for developing subchorionic hematoma (14).

What Are the Symptoms Of Subchorionic Hematoma?

Vaginal bleeding is one of the most common symptoms

Image: Shutterstock

One of the most common symptoms of subchorionic hematoma is vaginal bleeding. It can be either in the form of spotting or heavy bleeding. The bleeding may come along with severe abdominal pain or dizziness and cramping.

However, you may not know the reason behind the vaginal bleeding as hematoma can only be detected in an ultrasound scan.

How Is Subchorionic Hematoma Diagnosed?

Ultrasounds are used to detect subchorionic hematoma

Image: IStock

The only way to detect subchorionic hematoma is through an ultrasound. Depending on the intensity of vaginal bleeding, the doctor may use abdominal or transvaginal ultrasoundⁱXExamination of the uterus, cervix, ovaries, or pelvic organs by inserting an instrument through the vagina to create sound waves. to determine the reason for the bleeding (5).

An ultrasound can detect the blood clots between the uterus and placenta. The transvaginal method aids in examining the uterine area through the vagina.

Once the scan confirms SCH, the doctor will determine the size of the maternal hemorrhage as the size reflects the intensity of the problem.

Size Of Subchorionic Hematoma

The size of SCH is evaluated (6) depending on the elevation of the chorionic membrane from the uterus wall.

Typically, if the size of the hematoma is 50-66% of the gestational sac then it is large, and less than 20% of the sac is considered small (1). A large hematoma increases the chance of spontaneous abortion, but a small sized one is common during the first trimester.

Is Subchorionic Hematoma Harmful?

Smaller hematomas do not harm your pregnancy but result in bleeding. However, larger hematomas carry some serious pregnancy risks such as preterm delivery and placental abruptionⁱXA pregnancy complication in which the placenta detaches from the womb causing deprivation of nutrients and oxygen in the baby. (7). The risks of subchorionic hematoma are:

Subchorionic hematoma increases the risk of miscarriage in the first 20 weeks of pregnancy. However, vaginal bleeding in an ongoing pregnancy will not increase the chance of a miscarriage (8). Those who experience both bleeding and cramping have a higher risk of miscarriage compared to those without any symptoms.

Impact of pelvic floor exercises on the incidence and severity of UI in pregnancy

Source: The Impact of Pelvic Floor Exercises on the Quality of Life of Women with Urinary Incontinence – Analysis of Pregnancy and the Postpartum Period; Journal of Novel Physiotherapy and Physical Rehabilitation

SCH, in combination with any underlying pregnancy complication such as stress or injuries, also increases the chances of miscarriage (9).

Image: IStock

The outcome of the pregnancy with subchorionic hematoma depends on the size of the hematoma, gestational age, and the mother’s age (6).

The other risks associated with SCH include intrauterine fetal growth restriction, pre-eclampsiaⁱXA pregnancy complication characterized by high blood pressure and protein in the urine. , placental abruption or oligohydramnios.

Did you know?

At times, the subchorionic hematoma may shrink without any intervention and self-resolve (14).

Depending on the size of the hematoma, your doctor would suggest the course of treatment.

How Is Subchorionic Hematoma Treated?

Here is what your doctor might do/advice to treat this condition:

The doctor may order bed rest or advise you to minimize your activities if the hematoma size is small.

You may need to avoid sexual intercourse during this period.

The doctor may use estrogenⁱXA sex hormone responsible for the development of female sexual characteristics. or progesteroneⁱXA female reproductive hormone that plays a vital role in menstruation, pregnancy, and breastfeeding. therapy to strengthen your pregnancy. Dydrogesterone is a synthetic progesterone hormone that is administered orally (40mg/day) for treating subchorionic bleeding (10).

Blood thinners (anticoagulants) (11) may be advised to aid the removal of the blood clot.

Your doctor would closely monitor your health for fetal and uterine health.

You may support SCH treatment with some personal care.

Managing Subchorionic Hematoma

Here are some ways to deal with this pregnancy condition:

Keep track of any vaginal bleeding during pregnancy.
You should also look out for an antepartum hemorrhage that is characterized by bleeding from the birth canal after the 24th week of pregnancy (12).
Avoid heavy work and exercise.
Stay well hydrated to prevent constipation and straining at stool.
Take regular small meals with fiber.
Stay calm and stress-free.
Don’t miss any appointments with your doctor. Follow the doctor’s guidelines about bed rest and activity levels.

Image: IStock

Read on as we answer some commonly asked questions on SCH.

Frequently Asked Questions

1. What is subchorionic hemorrhage ICD 10 code?

Subchorionic hemorrhage ICD 10 code is O45 (12). Since this condition occurs due to the placental abruption, it is put under the category O45 that stands for ‘Premature separation of placenta’.

2. Can you experience subchorionic hemorrhage without bleeding?

Yes. You can have SCH without bleeding because the blood gets reabsorbed in the uterus. Even without vaginal bleeding, the risks associated with SCH remain the same (13).

3. What are the other causes of bleeding during pregnancy?

Some other causes of bleeding during pregnancy are:

Implantation
Intercourse
Cervical polypⁱXA small benign tumor in the lower part of the uterus connecting the vagina, the cervix.
Vaginal infection
Ectopic pregnancy
Miscarriage
Molar pregnancy

4. Can I have a healthy pregnancy with subchorionic hemorrhage?

Subchorionic hematoma is not uncommon in pregnancy, and studies demonstrate that pregnant women who are closely monitored go on to have healthy babies (14).

5. Can subchorionic hemorrhage cause birth defects?

There is a lack of sufficient evidence to support this conjecture. However, a few studies have reported that women with subchorionic hemorrhage are at a higher risk of stillbirth during pregnancy (15).

6. How long does it take for a subchorionic hematoma to go away?

Although there is no fixed time designated for the healing of subchorionic hematoma, a hematoma may shrink on its own or cause complications, depending on the size (16).

Subchorionic hematoma (SCH) during pregnancy is not very common. Nonetheless, it is seen in some pregnant women during the first trimester and is usually caused by auto-immune factors, infections, or other medical reasons. Although vaginal bleeding is a specific indication of SCH, it may not be the only reason, and there could be other causes why you may have spotting or bleeding during pregnancy. Therefore, it is essential to consult a doctor sooner to understand the reasons for vaginal bleeding. In most cases, bleeding due to a small-sized hematoma may not lead to serious pregnancy complications. Nevertheless, your doctor will be the right person to evaluate your condition.

Infographic: How Serious Is A Subchorionic Hematoma?

Subchorionic hematoma may not harm the baby most times. Small-sized hematomas may be resolved without causing any issues. Go through the infographic to learn more about subchorionic hematoma and pregnancy outcomes.

effects of subchorionic hematoma on pregnancy outcome (infographic)

Get high-quality PDF version by clicking below.

Download Infographic

Key Pointers

Subchorionic hematoma (SCH) is a rare accumulation of blood between the uterine and chorionic membranes during pregnancy.
SCH can cause vaginal bleeding during pregnancy and affects approximately 5-25% of pregnant women.
The exact cause of SCH is unknown, but certain factors such as poor placentation, abnormal implantation of the fertilized egg, age over 35, and blood coagulation disorders may increase the risk of developing SCH.
Symptoms of SCH include vaginal bleeding, dizziness, abdominal cramping, and pain.
While some cases of SCH may resolve on their own, others may require medication or hospitalization.

Sometimes pregnant women may experience bleeding during their first trimester. Watch this video to understand why this may happen and what exactly a subchorionic hematoma is.

References:

MomJunction's articles are written after analyzing the research works of expert authors and institutions. Our references consist of resources established by authorities in their respective fields. You can learn more about the authenticity of the information we present in our editorial policy.