Incomplete uterine evacuation with retention of placental/trophoblastic tissue within endometrial cavity

Solid, heterogeneous, echogenic mass

• ○
  

  Early loss often has small cystic areas

  
  
• ○
  

  Postpartum appears more like placenta

Persistent, thickened endometrium

• ○
  

  > 10 mm usually considered abnormal, but no consensus exists

Perform color Doppler to look for flow

• ○
  

  High-velocity, low-resistance flow

Lack of increased flow does not rule out RPOC

• ○
  

  40% of cases may have no or minimal flow

Normal postpartum uterus

• ○
  

  Small echogenic foci and fluid common

  
  
• ○
  

  Should decrease to < 8 mm with uterine involution

Intrauterine blood/clot

• ○
  

  Reported in up to 24% of postpartum patients

  
  
• ○
  

  More hypoechoic than RPOC

  
  
• ○
  

  No flow with Doppler

Delayed postpartum bleeding

• ○
  

  Most present within few days of delivery or abortion

RPOC is risk factor for endometritis

• ○
  

  Always consider RPOC in setting of postpartum fevers and pelvic pain

Use transvaginal scanning with color and pulsed wave Doppler in all cases

Carefully measure endometrial thickness

• ○
  

  If no mass or fluid and endometrial thickness < 10 mm without increased flow, RPOC extremely unlikely