What are the contraindications for subchorionic (subchorionic hematoma) hematoma during pregnancy?

Subchorionic Hematoma During Pregnancy: Contraindications and Management

Subchorionic hematoma (SCH) itself is not a contraindication to pregnancy continuation, but rather a complication requiring surveillance, with management focused on monitoring for adverse outcomes rather than specific activity restrictions. 1

Key Clinical Points

SCH Does Not Contraindicate Pregnancy Continuation

• SCH occurs in 7-27% of pregnancies and does not mandate pregnancy termination or specific contraindications to continuing pregnancy 1
• The presence of fetal cardiac activity is the most important prognostic factor and should be documented when evaluating SCH 1
• Transvaginal ultrasound is the primary diagnostic modality for detecting and monitoring SCH 1

What Activities Should Be Modified

While there are no absolute contraindications specific to SCH, certain precautions are warranted:

• Avoid excessive Valsalva maneuvers during labor if SCH is large or persists into later pregnancy, as this principle applies to conditions with bleeding risk 2
• Pulsed Doppler ultrasound should be avoided in the first trimester due to potential bioeffects on the developing embryo; use M-mode ultrasound or video clips to document cardiac activity instead 1
• Consider modified delivery planning (assisted delivery to shorten second stage) if large hematomas persist into the third trimester 2

Risk Stratification by Hematoma Size

Large SCH (>50% of gestational sac) carries significantly higher risk and requires intensified surveillance:

• Large SCH is associated with increased rates of early pregnancy loss, intrauterine growth restriction (IUGR), placental abruption, and preterm delivery 3
• Small to medium SCH generally has better prognosis, particularly when fetal cardiac activity is present 1, 3
• Massive SCH can cause space-occupying effects that compromise fetal blood supply and lead to fetal demise 4, 5

Surveillance Protocol

First Trimester Management

• Document fetal cardiac activity, hematoma location relative to placenta, and hematoma size 1
• Perform quantitative beta-hCG and complete blood count to assess for anemia and trend pregnancy viability 1
• Administer anti-D immunoglobulin (50 μg) to Rh-negative patients with vaginal bleeding to prevent alloimmunization 1
• Obtain blood type and screen if not already on file 1

Second and Third Trimester Management

For SCH persisting beyond the first trimester or newly diagnosed in later pregnancy:

• Serial growth ultrasounds to monitor for IUGR 6
• Umbilical artery Doppler studies, particularly if SCH is large or requires maternal blood transfusion 6
• Antenatal fetal testing should be considered for large hematomas 6
• SCH in second/third trimesters is associated with preterm birth, preterm prelabor rupture of membranes, fetal growth restriction, and neonatal pulmonary morbidity 6

Common Pitfalls to Avoid

• Do not confuse early first trimester SCH with normal decidual bleeding on ultrasound 1
• Do not mistake SCH for other conditions: differentiate from subamniotic hematomas, placental abruption, ectopic pregnancy, and nonviable intrauterine pregnancy 1
• Do not use hyperechoic appearance alone to rule out SCH, as massive hematomas can be difficult to differentiate from uterine or placental tumors on imaging 4
• Do not assume small SCH is always benign—even small hematomas warrant documentation and follow-up, though prognosis is generally favorable 1, 3

Risk Factors Associated with SCH

Known risk factors include:

• Maternal factor deficiency (coagulation disorders) 6
• Anticoagulation therapy 6
• Assisted reproduction 7
• Reproductive tract infection 7
• Abnormal coagulation function and autoimmune factors 7

Outcomes and Prognosis

• Small to medium SCH with documented fetal cardiac activity has favorable prognosis 1, 3
• Large SCH significantly increases risk of adverse outcomes: first trimester bleeding (most common), early pregnancy loss, IUGR, placental abruption, and preterm delivery 3
• Maternal morbidity increases with large SCH, particularly when hospitalization and blood transfusion are required 6
• No proven treatment exists for SCH; management is expectant with surveillance 6