1. Retained products of conception (RPOC) refers to incomplete evacuation of placental or trophoblastic tissue in the endometrial cavity after abortion, delivery, or cesarean section. 2. Ultrasound is first-line for diagnosis and may show an echogenic endometrial mass with low-resistance, high-velocity blood flow. Thickened endometrium (>10mm) or intrauterine fluid also suggest RPOC. 3. Differential diagnosis includes uterine atony, blood clots, or arteriovenous malformation. Presentation involves delayed bleeding or endometritis. Expectant management is appropriate for minimal vascularity; medication or surgery is

1. Retained Products of Conception
Dr.Mohamed Soliman
1 definition
2 best diagnostic clue
3 Ultrasound checklist
4 Color Doppler checklist
5 MRI
6 common differential diagnosis
7 clinical Issues
8 diagnostic checklist (8)
9 case studies
10 remember

2. Definition
Retained products of conception (RPOC)
Incomplete uterine evacuation with retention of placental/trophoblastic tissue
within endometrial cavity
May occur after abortion, vaginal delivery, or even cesarean section
Incomplete abortion

3. General features
Best diagnostic clue
○ Echogenic endometrial mass with low-resistance, high velocity flow
○ Early often has small cystic areas
○ Postpartum appears more like placenta

4. 1 Solid, heterogeneous, echogenic mass
Most sensitive (79%) and specific (89%) finding
2 Persistent, thickened endometrium
> 10 mm usually considered abnormal, but no consensus exists
Cut-off of 8 mm has 34% positive rate
> 13 mm has 85% sensitivity, 64% specificity
3 May have calcifications
4 Intrauterine fluid common
first-line investigation

5. • Color Doppler
5 High-velocity, low-resistance flow
Peak velocity highly variable: Reported from 10 cm/sec to > 100 cm/sec
Very high-velocity flow can be confused with arteriovenous malformation (AVM)
* Lack of increased flow does not rule out RPOC
40% of cases may have no or minimal flow

6. * an intracavitary uterine soft-tissue mass with variable amounts of enhancing
tissue and variable degrees of myometrial thinning and obliteration of the
junctional zone.
* Signal characteristics include:
T1: variable heterogeneous signal 1
T2: variable heterogeneous signal 1
T1 C+ (Gd): can show variable enhancement

7. Uterine Atony
• Primary differential consideration for immediate postpartum hemorrhage
• Usually not imaged, but blood/clot may potentially be confusing
Normal Postpartum Uterus
• Significant overlap in ultrasound findings between normal postpartum uterus
and RPOC
• Highly variable, from smooth to irregular endometrium
• Small echogenic foci and fluid common
• Foci of gas may be seen in up to 21%
• Should decrease to < 8 mm with uterine involution

8. Intrauterine Blood/Clot
• Reported in up to 24% of postpartum patients
• More hypoechoic than RPOC
• No flow with Doppler
• Changes/resolves on follow-up scans
Uterine Arteriovenous Malformation
• High flow within RPOC may simulate AVM
• Rare without history of prior instrumentation
• Within myometrium, not endometrium
• Persistent finding that remains after RPOC have been evacuated

9. Presentation
Most common signs/symptoms
Delayed postpartum bleeding , Most present within few days of delivery or
abortion
Other signs/symptom Endometritis
– Puerperal infection with postpartum fevers and pelvic pain
– RPOC is risk factor for endometritis, so both may be present
– May see gas in endometrium, nonspecific

10. Demographics
• Epidemiology
○ about 1% of all pregnancies
○ More frequent following termination
○ ↑ incidence with placenta accreta
Natural History & Prognosis
• Failure to evacuate → prolonged hemorrhage and infection

11. Treatment
• Expectant management
appropriate for those with little or no vascularity
May repeat ultrasound to reevaluate
• Medical treatment (misoprostol)
typically used for incomplete abortion
• Surgical treatment (dilation and curettage) for significant bleeding and
associated endometritis

12. 1 Endometrial Solid, heterogeneous, echogenic mass
2 Persistent, thickened endometrium (> 10 mm usually considered abnormal)
3 May have calcifications
4 Intrauterine fluid common
5 High-velocity, low-resistance flow (PSV 10 cm/sec to > 100 cm/sec)
6 Consider Uterine atony vs. RPOC primary differential for postpartum
Hemorrhage
7 Consider RPOC in any patient presenting with Endometritis
8 If no mass or fluid and endometrial thickness < 10 mm without increased flow,
RPOC extremely unlikely

13. Case studies

14. 1st case

15. Female patient with first trimester abortion
Endometrial complex echogenic mass with small cystic areas

16. chaotic arterial and venous flow
can be confused with an arteriovenous malformation.
This flow will resolve after evacuation of the retained products.
Female patient with first trimester abortion

17. 2nd case

18. no endometrial mass,
Diffuse endometrial thickening with an area of increased color flow .
Increased vascularity within a thickened postpartum endometrium is highly suggestive of RPOC

19. 3rd case

20. Marked thickening of the endometrium but no flow on color Doppler.
remember : up to 40% of RPOC cases, there is little or no flow on Doppler imaging.

21. 4th case

22. 32 years old patient with history of abortion since 2 days
Endometrial echogenic mass with areas of cystic degenerations

23. 32 years old patient with history of abortion since 2 days
Prominent vascularity within the endometrial content , cystic areas shows no vascularity

24. 32 years old patient with history of abortion since 2 days
Pulsed wave doppler shows
* high velocity ( PSV = 50 cm/s)
* Low resistance flow ( high diastole)

25. 5th case

26. Sagital T2 WI retained placental tissue at lower
uterine segment and upper cervix .

27. Axial T1 WI shows
retained placental tissue

28. Coronal MRI shows retained placental
tissue

29. Coronal MRI shows retained placental
tissue

30. 6th case

31. A case of retained products of conception

32. A case of retained products of conception

33. A case of retained products of conception

34. A case of retained products of conception

35. A case of retained products of conception

36. 7th case

37. MRI of RPOC
• no definite fetal parts
• Placenta was separate with
retroplacental hemorrhage
• Products of conception are seen
through opened internal os.

38. MRI of RPOC
• no definite fetal parts
• Placenta was separate with retroplacental
hemorrhage
• Products of conception are seen through opened
internal os.

39. MRI of RPOC
• no definite fetal parts
• Placenta was separate with retroplacental hemorrhage
• Products of conception are seen through opened internal os.

40. 8th case

41. Echogenic, somewhat heterogeneous and
vascular intrauterine contents in a post-partum
female.
Retained products of conception

42. Retained products of conception

43. Retained products of conception

44. 9th case

45. Retained products of conception

46. 10th case

56. Uterus is anteveted.
It shows normal echopattern measuring 73 x 44 x 42 mm.
No focal mass lesion in noted.
Heterogeneous echopattern area ( 25 x 15 x 10 mm ) with vascularity is noted in endometrial
canal.
RIght ovary - a thin walled cyst with internal strands - 37 x 36 mm
Left ovary - a thin walled cyst with internal strands - 24 x 23 mm
No extra-ovarian adnexal mass lesion is noted.
No free fluid is seen in pelvis.

57. 11th case

58. Post abortion patient had history of spotting PV and ultrasound images showing thickened
endometrium with increased vascularity within suggestive of retained products of conception.

59. 1 Endometrial Solid, heterogeneous, echogenic mass
2 Persistent, thickened endometrium (> 10 mm usually considered abnormal)
3 May have calcifications
4 Intrauterine fluid common
5 High-velocity, low-resistance flow (PSV 10 cm/sec to > 100 cm/sec)
6 Consider Uterine atony vs. RPOC primary differential for postpartum
Hemorrhage
7 Consider RPOC in any patient presenting with Endometritis
8 If no mass or fluid and endometrial thickness < 10 mm without increased flow,
RPOC extremely unlikely