Management of Small Subchorionic Hematoma in the First Trimester

Diagnosis and Assessment

The American College of Radiology recommends documenting the location of the subchorionic hematoma relative to the placenta when evaluating SCH, and notes that transvaginal ultrasound is the primary imaging modality for diagnosing subchorionic hematoma (SCH) in early pregnancy 1
The presence of fetal cardiac activity should be documented when evaluating SCH, as recommended by the Radiology society 2

The American College of Radiology notes that prognosis is better when fetal cardiac activity is present, and that this factor is associated with favorable outcomes 3

The American College of Emergency Physicians recommends administering anti-D immunoglobulin (50 μg) to Rh-negative patients with vaginal bleeding to prevent alloimmunization, which is a Level C recommendation based on clinical consensus 4

The American College of Radiology recommends avoiding pulsed Doppler ultrasound of the pregnancy in the first trimester due to potential bioeffects on the developing embryo, and instead documenting embryonic cardiac activity using M-mode ultrasound or video clips 1, 3

The American College of Radiology recommends transvaginal ultrasound as the primary imaging modality for diagnosing subchorionic hematoma (SCH), especially in early pregnancy, with SCH occurring in 7% to 27% of pregnancies 5
SCH can be detected during ultrasound evaluation of first trimester vaginal bleeding, and must be differentiated from other placental abnormalities, such as subamniotic hematomas and placental abruption 5
Early first trimester SCHs may be confused with normal decidual bleeding, and SCH in second and third trimesters can be more difficult to diagnose and manage, but can be distinguished from other causes of first trimester bleeding, including ectopic pregnancy and nonviable intrauterine pregnancy 5

The American College of Emergency Physicians recommends quantitative beta-hCG level and complete blood count as part of the diagnostic workup for patients with subchorionic hematoma, to assess for anemia from bleeding and trend beta-hCG levels 6
Blood type and screen should be performed if not already on file, as part of the initial workup for patients with subchorionic hematoma 6

The American College of Radiology recommends transvaginal ultrasound as the primary diagnostic modality to document presence of fetal cardiac activity, hematoma location relative to the placenta, and hematoma size as percentage of gestational sac 7
The American College of Emergency Physicians suggests administering 50 μg anti-D immunoglobulin to Rh-negative patients with any first trimester bleeding to prevent alloimmunization, even with viable pregnancy and fetal cardiac activity present 8

First trimester bleeding occurs in 7-27% of all pregnancies, with overall miscarriage risk of approximately 12%, according to the Journal of the American College of Radiology 7