Bleeding in early pregnancy can be a scary. Unfortunately, it is very common and can have many causes, most of which are no direct threat to the pregnancy. These can include a vaginal infection, a urinary tract infection, and postcoital (after sex) bleeding. While bleeding can be a sign of a miscarriage, it can also be due to a subchorionic hemorrhage. Subchorionic hemorrhage, also known as a subchorionic hematoma, is a frequent cause of vaginal bleeding in early pregnancy.
Bleeding occurs between the chorion, one of the fetal membranes, and the wall of the uterus. They are frequently found during ultrasound evaluation of early pregnancy bleeding. They can also be noted in women with no symptoms during routine dating ultrasounds.
When a subchorionic hemorrhage is found and there is a fetal heart beat detected, a diagnosis of “threatened miscarriage/abortion” will be given. This term, while scary, is used for almost any vaginal bleeding in pregnancy, and does not automatically mean that you are having a miscarriage (a miscarriage that is in the process of happening is called an inevitable abortion/miscarriage). In women with a small, asymptomatic subchorionic hematoma, there is not an increased risk of miscarriage. For example, if you are getting a routine dating ultrasound and your doctor mentions the hematoma as an incidental finding, then as long as you have not had bleeding , you do not have any higher chance of miscarrying than if the hematoma was not there.
However, a research review shows that women with larger, bleeding hematomas are at risk of having worse outcomes. Tuuli et al (2011) found that women with these symptomatic hematomas were at increased risk of having miscarriage in early pregnancy, and of stillbirth later in pregnancy. They found that, “One extra spontaneous abortion [miscarriage] is estimated to occur for every 11 women with subchorionic hematoma and one extra stillbirth occurs for every 103 women with subchorionic hematoma diagnosed.” this means that 1 in 11 women diagnosed with a bleeding hematoma will have a miscarriage, and 10 in 11 will not. They also found an increased risk of abruption (where the placenta tears away from the uterus prematurely), preterm delivery, and preterm premature rupture of membranes (water breaking before 37 weeks). Subchorionic hematoma was not associated with an increased risk of small for gestational age (small babies), or preeclampsia (elevated blood pressure with other organ involvement in pregnancy).
Unfortunately, once a subchorionic hematoma has been diagnosed, there is nothing that can be done to prevent it from progressing. Please keep in mind that you did not do anything to cause the hematoma. Signs of progression can include heavier bleeding and increased cramping. Although this is a very nerve-wracking time, the majority of pregnancies with the complication do go on to be normal and healthy. Typically, once the bleeding has stopped, the hematoma resolves (gets reabsorbed) and the pregnancy continues as normal. No extra follow up or testing is usually needed as long as bleeding has stopped and the baby has a heart beat. If bleeding continues, depending on how early the pregnancy is, there may be extra blood tests to check hcg levels (a pregnancy hormone that should double every 48-72 hours in early pregnancy), or weekly ultrasounds to check if the baby has a heart beat if it is too early to listen with a doppler. While in limbo and waiting, try to be gentle with yourself. Remember that it’s not your fault, and most pregnancies continue on without issue. Don’t forget self-care while going through this stressful period. Don’t be afraid to ask your provider questions if you have them. If your provider is cold or unsupportive, find a new one.
If you have any questions about this post, or would like additional research, don’t hesitate to ask!
Tuuli MG, Norman SM, Odibo AO, Macones GA, Cahill AG. Perinatal outcomes in women with subchorionic hematoma: a systematic review and meta-analysis. Obstet Gynecol. 2011 May. 117(5):1205-12.
This post is not intended to be individual medical advice. If you are having a problem, please contact your medical provider.