Retained products of conception
Citation, DOI & article data
Retained products of conception (RPOC) refer to the persistence of placental and/or fetal tissue in the uterus following delivery, termination of pregnancy or a miscarriage.
RPOC complicate ~1-5% of all routine vaginal deliveries 12.
According to one prospective study, RPOC was present after a third-trimester delivery in around 2.7% of women, whereas it was diagnosed in pregnancies ending during the second and first trimesters in 40% and 17% respectively 12.
It occurs with greater frequency with:
Common symptoms include vaginal bleeding and abdominal or pelvic pain, similar to patients with gestational trophoblastic disease. Some patients may have a fever 11.
Differentiation of these entities is important because retained products of conception are treated conservatively or with curettage, while gestational trophoblastic disease may require chemotherapy.
ß-human chorionic gonadotropin (beta-hCG) remains elevated in patients with gestational trophoblastic disease but falls to an undetectable level over 2-3 weeks, in cases of retained products.
Ultrasound is typically the first-line investigation in suspected retained products of conception:
- a variable amount of echogenic or heterogeneous material within the endometrial cavity
- in some instances, this may present as an endometrial or intrauterine mass
- presence of vascularity within the endometrial echogenic material supports the diagnosis but the absence of color Doppler flow has a low negative predictive value because retained products of conception may be avascular 9
- calcification may be present
Retained products of conception can be suspected on ultrasound if the endometrial thickness is >10 mm following dilatation and curettage or spontaneous abortion (80% sensitive) ref.
Three vascularity patterns have been established on Doppler ultrasound 12:
- type 1: minimal endometrial vascularity less than the myometrium
- type 2: moderate vascularity with nearly equal endometrial and myometrial vascularity
- type 3: marked endometrial vascularity more than adjacent myometrium
- arterial flow velocities >100 cm/sec can occur with low-resistance spectral waveform and large vessels present, potentially mimicking a uterine arteriovenous malformation
MRI appearance is variable and consists of soft tissue within the endometrial cavity, which may be variably enhancing. There may be a variable degree of associated myometrial thinning and obliteration of the junctional zone.
Signal characteristics include 1:
- T1: variable heterogeneous signal
- T2: variable heterogeneous signal
- T1 C+ (Gd): variable enhancement
For ultrasound appearances consider:
- normal postpartum appearance
- blood clot within the endometrial cavity (often co-exists): non-vascular on color Doppler ultrasound
- gestational trophoblastic disease
- uterine arteriovenous malformation: more prominent blood flow is present; usually centered in the myometrium 12
- 1. Noonan J, Coakley F, Qayyum A, Yeh B, Wu L, Chen L. MR Imaging of Retained Products of Conception. AJR Am J Roentgenol. 2003;181(2):435-9. doi:10.2214/ajr.181.2.1810435 - Pubmed
- 2. Nalaboff K, Pellerito J, Ben-Levi E. Imaging the Endometrium: Disease and Normal Variants. Radiographics. 2001;21(6):1409-24. doi:10.1148/radiographics.21.6.g01nv211409 - Pubmed
- 3. Carol M. Rumack. Diagnostic Ultrasound. (2011) ISBN: 9780323053976 - Google Books
- 4. Leyendecker J, Gorengaut V, Brown J. MR Imaging of Maternal Diseases of the Abdomen and Pelvis During Pregnancy and the Immediate Postpartum Period. Radiographics. 2004;24(5):1301-16. doi:10.1148/rg.245045036 - Pubmed
- 5. Kido A, Togashi K, Koyama T et al. Retained Products of Conception Masquerading as Acquired Arteriovenous Malformation. J Comput Assist Tomogr. 2003;27(1):88-92. doi:10.1097/00004728-200301000-00016 - Pubmed
- 6. Durfee S, Frates M, Luong A, Benson C. The Sonographic and Color Doppler Features of Retained Products of Conception. J Ultrasound Med. 2005;24(9):1181-6; quiz 1188. doi:10.7863/jum.2005.24.9.1181 - Pubmed
- 7. Sadan O, Golan A, Girtler O et al. Role of Sonography in the Diagnosis of Retained Products of Conception. J Ultrasound Med. 2004;23(3):371-4. doi:10.7863/jum.2004.23.3.371 - Pubmed
- 8. Abbasi S, Jamal A, Eslamian L, Marsousi V. Role of Clinical and Ultrasound Findings in the Diagnosis of Retained Products of Conception. Ultrasound Obstet Gynecol. 2008;32(5):704-7. doi:10.1002/uog.5391 - Pubmed
- 9. Kamaya A, Petrovitch I, Chen B, Frederick C, Jeffrey R. Retained Products of Conception: Spectrum of Color Doppler Findings. J Ultrasound Med. 2009;28(8):1031-41. doi:10.7863/jum.2009.28.8.1031 - Pubmed
- 10. Aseeja V. Management of Retained Products of Conception with Marked Vascularity. J Turk Ger Gynecol Assoc. 2012;13(3):212-4. doi:10.5152/jtgga.2012.31 - Pubmed
- 11. Guarino A, Di Benedetto L, Assorgi C, Rocca A, Caserta D. Conservative and Timely Treatment in Retained Products of Conception: A Case Report of Placenta Accreta Ritention. Int J Clin Exp Pathol. 2015;8(10):13625-9. PMC4680531 - Pubmed
- 12. Sellmyer M, Desser T, Maturen K, Jeffrey R, Kamaya A. Physiologic, Histologic, and Imaging Features of Retained Products of Conception. Radiographics. 2013;33(3):781-96. doi:10.1148/rg.333125177 - Pubmed