What Is a Subchorionic Hemorrhage?
A subchorionic hemorrhage, also called a subchorionic hematoma, is bleeding between the amniotic sac and the uterine wall. This can occur from the placenta disconnecting from the original site of implantation, resulting in bleeding of the chorionic membranes—the outer layer of the amniotic sac. Many people, hearing the word “hemorrhage,” imagine pools of blood and worst-case scenarios. But a subchorionic hemorrhage is usually not quite as drastic as it sounds. You are more likely to have a subchorionic hemorrhage if you are pregnant after in vitro fertilization (IVF) or a thawed embryo transfer. You may also have a higher incidence if you are pregnant with a baby that is not your first baby. Age can also be a factor.
How Common Is Subchorionic Hemorrhage?
Subchorionic hemorrhage happens in almost 2% of all pregnancies, but it is the cause of about 20% of all bleeding in the first trimester. About a quarter of pregnant people experience bleeding in the first trimester. A subchorionic hemorrhage may cause bleeding that is visible, or you may only see it during an ultrasound done in pregnancy for a different reason. It can be varying in quantity from spotting to heavy bleeding. The blood can be pink, red, bright red or brown. If you are spotting or bleeding, your health care provider may use ultrasound to determine the cause.
Pregnancy Outcomes
Any bleeding during pregnancy may increase the risks of complications. People who have a subchorionic hemorrhage are at an increased risk for miscarriage and preterm labor. However, the risk is dependent on the size, location, symptoms, and timing in the pregnancy. The larger the area of bleeding, the more likely you are to have a complication, though this is certainly not true for all cases.
A Word From Verywell
Many people experience bleeding during pregnancy and go on to have healthy babies. If you are bleeding or spotting, contact your doctor or midwife, who will likely ask you about the amount, timing, and color of the blood you are seeing. You may be asked to come into the office to get checked out, or your practitioner may recommend rest and watchful waiting. Your doctor or midwife can help you understand what your specific risk factors are as well as the likelihood that bleeding will cause problems in your current pregnancy. Routine prenatal care, certain prenatal tests, and good follow-up will be helpful.
