A subchorionic bleed is also called a subchorionic hemorrhage. It refers to a collection of blood that can develop between the gestational membranes, such as the placenta, and the uterus during pregnancy.
This blood can lead to vaginal bleeding during pregnancy. This article will look at the causes and risks of a subchorionic hemorrhage (SCH), as well as explore other reasons for vaginal bleeding during pregnancy.
Subchorionic bleeding is when blood collects between the uterus and the gestational membranes during pregnancy.
This is a frequent cause of vaginal bleeding during the first and second trimester of pregnancy.
According to March of Dimes, many women experience light bleeding or spotting from the vagina during pregnancy. Spotting does not require a pad or tampon, and it can occur at any time between conception and giving birth.
SCH is one cause of bleeding from the vagina during early pregnancy.
Some other causes of bleeding or spotting in early pregnancy are:
- sexual intercourse
- an infection
- implantation bleeding
- changes in the cervix
Other more serious causes of bleeding in early pregnancy are:
- pregnancy loss
- ectopic pregnancy, which is when a fertilized egg implants somewhere other than the womb
- molar pregnancy, which is a rare mass of tissues that forms inside the womb instead of a fetus
Researchers are not sure why SCH occurs in some people and not others.
The collection of blood between the womb and the gestational membranes can result in blood clots called subchorionic hematomas, which can be small or large and may lead to vaginal bleeding.
As well as bleeding from the vagina, other symptoms of SCH may include pelvic pain and cramping.
Some women will not experience any symptoms at all, and will only find out they have SCH during a routine ultrasound examination.
Subchorionic bleeding does not usually cause any problems. However, research on whether SCH can cause pregnancy complications, such as preterm delivery or pregnancy loss, varies.
For example, a 2012 review found possible links between SCH and a higher risk of giving birth prematurely and of pregnancy loss. However, a 2013 study found that SCH did not increase the risk of pregnancy loss.
Another possible complication is placental abruption. This is a severe complication that happens when the placenta detaches from the womb lining.
The main symptom of placental abruption is vaginal bleeding, but a pregnant woman may also feel discomfort and tenderness, and a pain in the belly or back that comes on suddenly and does not go away.
Anyone who experiences vaginal bleeding during pregnancy should speak to a doctor.
To diagnose the cause of the bleed, a doctor will usually perform a physical examination and may order blood tests. They may also suggest an ultrasound examination.
An ultrasound uses high-frequency sound waves to generate a black and white image of the fetus and placenta on a screen.
If a person is experiencing subchorionic bleeding, the areas of blood inside the uterus will show up on this picture.
In most cases, SCH does not require treatment. Most doctors will recommend the woman restrict some activities, such as sexual intercourse, and get plenty of rest.
A doctor and other members of the healthcare team will also monitor women with SCH until bleeding stops, or the SCH itself resolves.
Although subchorionic bleeding is common in the first trimester, it is still best to speak to a doctor to get a correct diagnosis whenever bleeding occurs in pregnancy.
Most SCHs are not harmful, but some research suggests links to some adverse pregnancy complications.