From the Guidelines
A small subchorionic hemorrhage in early pregnancy is generally not a cause for major concern and often resolves on its own without treatment. According to the American College of Radiology Appropriateness Criteria, ultrasound is the primary imaging modality for evaluating patients with vaginal bleeding in the first trimester of pregnancy 1. The study highlights that bleeding in the first trimester occurs in 7% to 27% of pregnancies, with an overall risk of miscarriage of approximately 12% 1.
Key Considerations
- No specific medications or interventions are typically needed for small subchorionic hemorrhages.
- Pelvic rest may be recommended to avoid exacerbating the condition.
- Regular prenatal appointments are crucial for monitoring the hemorrhage through ultrasound.
- Increased vaginal bleeding, severe abdominal pain, or cramping require immediate medical attention.
Clinical Implications
Subchorionic hemorrhages occur due to partial placental separation, resulting in blood collection between the uterine wall and the chorion (outer fetal membrane) 1. Most small subchorionic hemorrhages resolve spontaneously as pregnancy progresses, and the majority of pregnancies with small subchorionic hemorrhages continue normally to term. It is essential to balance the need for monitoring with the risk of overinterpretation of ultrasound findings, which can lead to potential harm to a normal pregnancy 1.
Monitoring and Follow-up
Regular ultrasound monitoring can help track the resolution of the hemorrhage and ensure the pregnancy is progressing normally. The American College of Radiology Appropriateness Criteria emphasizes the importance of correlating ultrasound findings with serum human chorionic gonadotropin (hCG) levels and clinical presentation to differentiate causes of first-trimester bleeding 1. By prioritizing a cautious approach and avoiding unnecessary interventions, healthcare providers can minimize the risk of complications and support a healthy pregnancy outcome.
From the Research
Definition and Diagnosis of Subchorionic Hemorrhage
- Subchorionic hemorrhage (SCH) is a condition where blood accumulates between the chorion and decidua basalis due to the separation of the chorion and decidua basalis 2.
- SCH is mainly detected by ultrasound, which shows an hypoechoic or anechoic crescent-shaped fluid dark area on ultrasound images 2.
- The diagnosis of SCH is usually made by ultrasound imaging 3.
Risk Factors and Etiology
- The only known risk factors for SCH are maternal factor deficiency and anticoagulation therapy 3.
- Current studies suggest that the occurrence of SCH may be related to several factors, such as abnormal coagulation function, autoimmune factors of pregnant women, assisted reproduction, drug use during pregnancy, and reproductive tract infection 2.
- However, the exact etiology of SCH remains unclear 2.
Pregnancy Outcomes and Complications
- SCH has been associated with several adverse fetal outcomes, including preterm birth, preterm prelabor rupture of membranes, fetal growth restriction, fetal demise, and neonatal pulmonary morbidity 3.
- The presence of SCH in early pregnancy is associated with an increased risk of spontaneous abortion 4, 5.
- Specific ultrasound features of SCH, such as a wrapping location with moderate size, may be indicative of increased risk of miscarriage or post-natal complications 4.
- Jaundice and premature births may have an association with placental compromise 4.
Management and Treatment
- There is no proven treatment for SCH, although there are several investigational therapies reported 3.
- Serial growth ultrasounds, umbilical artery Doppler studies, and antenatal fetal testing should be considered, particularly if the SCH is large or treatment requires a maternal blood transfusion 3.
- However, there are no uniform clinical treatment guidelines for SCH, and its management can be complex and difficult 3, 2.