Any type of bleeding during pregnancy can be alarming. About 25% of women experience some bleeding or spotting during their pregnancy.

Subchorionic hematomas are the cause of about 20% of all bleeding during the first trimester. This is a type of bleeding that occurs between amniotic membranes. It occurs when the placenta partially detaches from where it was implanted in the wall of uterus.

What Causes a Subchorionic Hematoma?

The specific causes of subchorionic hematoma aren't clear. There are some risk factors associated with them, including: 

Malformation of the uterus

History of recurrent miscarriages

History of pelvic infections

Trauma

Early-onset preeclampsia, which is a serious pregnancy complication marked by high blood pressure and organ failure

Severe high blood pressure

In vitro fertilization 

How Common Is Subchorionic Hematoma?

This condition is detected through ultrasound, during the first trimester of pregnancy. Around 25 of every 100 women experience vaginal bleeding during the first half of pregnancy. Women who have undergone IVF are more prone to subchorionic hematoma.

How Is Subchorionic Hematoma Different from Spotting?

Subchorionic hemorrhage shouldn’t be mistaken for spotting. When there are just a few spots of blood on undergarment, it’s spotting. However, subchorionic hematoma results in both bleeding and spotting. It may necessitate undergarment liners. The bleeding may also be accompanied by severe abdominal pain and dizziness.

Risks & Complications

Subchorionic hematoma towards the end of the first trimester or early second trimester can fractionally tear away the developing placenta from its site of attachment. Large hematomas can tear away up to 40% of the placenta from the endometrium and can grow larger in size, thereby applying pressure on the gestational area and rupture the membrane and lead to abortion. Subchorionic hematomas occurring beneath or, at the edge of the placenta or, behind an isolated area of the fetal membrane can be a cause of concern. Large intrauterine hematomas can restrict the growth of the fetus and hamper the mother’s health. In worst case scenario, it may result in death of the embryo.

Role of Dydrogesterone (A novel retroprogesterone), in subchorionic hematoma:

Inhibits the production of Th1 cytokines and increases Th2 cytokines.

Initiates angio-reconstruction and revascularization.

Recovers embryo from high risk of subchorionic hemorrhage.