A subchorionic hematoma is a collection of blood that forms between the placenta and the uterine wall when the fertilized egg partially separates from the uterus. This most often occurs during the first trimester of pregnancy.
This condition may cause vaginal bleeding, abdominal pain, and a sensation of tightening or contractions in the abdomen. In some cases, there may be no symptoms at all.
When symptoms are absent, a subchorionic hematoma may only be found during routine prenatal testing. If a subchorionic hematoma is suspected, evaluation by an OBGYN is recommended.
Common symptoms
The main symptoms of a subchorionic hematoma are:
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Vaginal bleeding;
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A sensation of tightening or contractions in the abdomen;
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Abdominal pain.
However, a subchorionic hematoma may sometimes cause no symptoms and is identified only on ultrasound, which is commonly performed as part of prenatal care.
Is a subchorionic hematoma serious?
A subchorionic hematoma can be serious in some cases and may increase the risk of complications such as preterm birth, miscarriage, and placental abruption, especially when the hematoma is large or occurs early in pregnancy.
Confirming a diagnosis
A subchorionic hematoma is diagnosed by an OBGYN based on symptoms (when present) and imaging tests such as ultrasound, which can show a hematoma within the uterus.
If vaginal bleeding occurs during pregnancy, prompt evaluation by an obstetric emergency service is recommended, as it may be a sign of miscarriage, especially before 20 weeks of gestation. Learn more about other possible causes of bleeding during pregnancy and what it could mean.
Possible causes
The exact cause of subchorionic hematoma is not completely understood. It is more common in people with uterine wall abnormalities, a history of miscarriage, or uterine infections.
Treatment options
Treatment depends on the size of the hematoma, the mother’s age, and how far along the pregnancy is. In most cases, no specific treatment is needed, and the hematoma tends to resolve within 1 to 2 weeks.
During this period, management is typically rest and regular follow-up with an obstetrician. It is common for the doctor to recommend repeat ultrasounds to monitor the hematoma’s size as well as the health of the fetus.
Additional precautions may also be recommended to reduce the chance of the hematoma increasing in size, including:
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Avoiding sexual intercourse;
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Avoiding standing for long periods, with a preference for sitting or lying down;
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Avoiding physical strain, such as lifting heavy objects or exercising.
In more severe cases, hospitalization may be required to prevent potentially life-threatening complications for the pregnant person or the fetus, such as low blood pressure due to blood loss or signs of fetal distress.