Management of Subchorionic Hematoma
Conservative management with close monitoring is the primary approach for subchorionic hematoma, with bed rest potentially reducing spontaneous abortion rates and progesterone therapy showing benefit in preventing pregnancy loss. 1, 2
Initial Assessment
When subchorionic hematoma (SCH) is diagnosed by ultrasound (appearing as hypoechoic or anechoic crescent-shaped fluid collection between chorion and decidua), document the following specific parameters 3:
- Hematoma size and volume - larger hematomas requiring blood transfusion carry worse prognosis 1
- Gestational age at diagnosis - typically presents with first trimester bleeding 2
- Presence of viable embryo/fetus - management only applies when fetal cardiac activity is present 2, 4
- Severity of vaginal bleeding - though duration does not predict outcome 2
Primary Management Strategy
Bed Rest
Strict bed rest at home for the duration of vaginal bleeding significantly improves outcomes 2:
- Reduces spontaneous abortion rate from 23.3% to 9.9% (p=0.006) 2
- Increases term pregnancy rate from 70% to 89% (p=0.004) 2
- Continue until bleeding ceases and hematoma resolves on ultrasound 2
Progesterone Therapy
Oral dydrogesterone 40 mg/day is the preferred progestogenic agent 4:
- Reduces abortion rate to 7% compared to 18.7% with micronized progesterone (37% relative reduction) 4
- Works through immunomodulatory effects maintaining T helper-2 cytokine balance 4
- Particularly effective even with large-volume hematomas and poor prognosis 4
Monitoring Protocol
Serial ultrasound examinations at 7-day intervals until one of the following occurs 2:
- Vaginal bleeding ceases
- Subchorionic hematoma disappears
- Spontaneous abortion occurs
For second and third trimester SCH, intensified surveillance is required 1:
- Serial growth ultrasounds to detect fetal growth restriction 1
- Umbilical artery Doppler studies 1
- Antenatal fetal testing 1
- More frequent monitoring if hematoma is large or maternal blood transfusion needed 1
Additional Supportive Measures
For massive subchorionic hematomas with complications, consider 5:
- Tocolysis with ritodrine infusion if preterm labor threatens 5
- 10% maltose infusion therapy (1500 mL/day) for oligohydramnios 5
- Antibiotic prophylaxis (e.g., cefotaxime sodium 2 g/day × 7 days) if infection risk 5
Important Caveats
The following factors do NOT predict pregnancy outcome and should not alter management 2:
- Duration of vaginal bleeding
- Hematoma size at diagnosis
- Gestational age at diagnosis
Known risk factors to address 1:
- Maternal factor deficiency (coagulation abnormalities)
- Anticoagulation therapy - may require adjustment
Associated adverse outcomes requiring vigilance 1:
- Preterm birth
- Preterm prelabor rupture of membranes
- Fetal growth restriction
- Fetal demise
- Neonatal pulmonary morbidity
When to Escalate Care
Hospitalization and blood transfusion indicated when 1:
- Large SCH causing significant maternal blood loss
- Hemodynamic instability
- Severe anemia requiring transfusion
These cases require the most intensive fetal surveillance protocols 1
The evidence for bed rest comes from a retrospective study showing significant benefit, though the authors acknowledge lack of randomization 2. The progesterone data, while from a smaller uncontrolled study, demonstrates marked improvement over historical controls 4. No formal guidelines exist for SCH management, making these the best available evidence-based interventions 1, 3.