Predictive value of sonographic examination to visualize retained placenta directly after birth at 16 to 28 weeks

The accuracy of ultrasound scan in diagnosing retained products of conception: a systematic review and meta-analysis

OBJECTIVE

This study aimed to analyze and summarize the evidence on the accuracy of different ultrasound methods in the diagnosis of retained products of conception.

DATA SOURCES

We searched Ovid SP, the Cumulative Register to Nursing & Allied Health Literature, EBSCO, and grey literature including Core, Trip, Networked Digital Library of Theses and Dissertations Global ETD search, BMJ Best Practice, PubMed, GreyLit report website (http://www.greylit.org/), Cochrane Central Register of Controlled Trials, and Google scholar (https://scholar.google.com/).

STUDY ELIGIBILITY CRITERIA

We included prospective and retrospective cross-sectional or Cohort studies that evaluated both ultrasound findings (before management of retained products of conception) and histopathologic results of retained products of conception at all gestational ages.

METHODS

We used Covidence for data extraction from the studies and quality assessment. The meta-analysis was performed using RevMan 5.4 (forest plot), MetaDTA version 2.01, and Meta-DiSc 2.0 online software.

RESULTS

In total, 11 studies were eligible for data extraction and meta-analysis. The total number of study participants from these 11 studies were 1567. Of these, 9 studies were included to test the accuracy of an echogenic mass, 4 studies analyzed the accuracy of endometrial thickness, and 5 studies analyzed the accuracy of color Doppler flow to predict retained products of conception. We found that echogenic mass had the highest sensitivity, specificity, and diagnostic odds ratio for predicting retained products of conception. The sensitivity, specificity, and diagnostic odds ratio were 0.915 (95% confidence interval, 0.844-0.955), 0.843 (95% confidence interval, 0.615-0.947), and 57.787 (95% confidence interval, 15.171-220.112), respectively. The diagnostic threshold for endometrial thickness was set at 10 mm with a sensitivity, specificity, and diagnostic odds ratio of 0.667 (95% confidence interval, 0.072-0.981), 0.866 (95% confidence interval, 0.375-0.986), and 12.927 (95% confidence interval, 0.23-726.582). The sensitivity, specificity, and diagnostic odds ratio of color Doppler flow were 0.850 (95% confidence interval, 0.756-0.913), 0.406 (95% confidence interval, 0.198-0.655), and 3.893 (95% confidence interval, 1.005-15.081).

CONCLUSION

Our review concluded that an echogenic mass is the most sensitive and specific predictor of retained products of conception after any pregnancy event. The most important limitation of our review is that the design of the studies included led to significant statistical heterogeneity.

Clinical significance of retained products of conception in placenta previa: a retrospective analysis

BACKGROUND

Retained products of conception (RPOC) often cause severe postpartum hemorrhage (PPH) but the clinical significance of RPOC in placenta previa is unclear. This study aimed to investigate the clinical significance of RPOC in women with placenta previa. The primary outcome was to evaluate risk factors of RPOC and the secondary outcome was to consider risk factors of severe PPH.

METHODS

Singleton pregnant women with placenta previa who underwent cesarean section (CS) and placenta removal during the operation at the National Defense Medical College Hospital between January 2004 and December 2021 were identified. A retrospective analysis was performed to examine the frequency and risk factors of RPOC and the association of RPOC with severe PPH in pregnant women with placenta previa.

RESULTS

This study included 335 pregnant women. Among these, 24 (7.2%) pregnant women developed RPOC. Pregnant women with prior CS (Odds Ratio (OR) 5.98; 95% Confidence Interval (CI) 2.35-15.20, p < 0.01), major previa (OR 3.15; 95% CI 1.19-8.32, p < 0.01), and placenta accreta spectrum (PAS) (OR 92.7; 95% CI 18.39-467.22, p < 0.01) were more frequent in the RPOC group. Multivariate analysis revealed that prior CS (OR 10.70; 95% CI 3.47-33.00, p < 0.01,) and PAS (OR 140.32; 95% CI 23.84-825.79, p < 0.01) were risk factors for RPOC. In pregnant women who have placenta previa with RPOC or without RPOC, the ratio of severe PPH were 58.3% and 4.5%, respectively (p < 0.01). Furthermore, the occurrence of prior CS (OR 9.23; 95% CI 4.02-21.20, p < 0.01), major previa (OR 11.35; 95% CI 3.35-38.38, p < 0.01), placenta at the anterior wall (OR 3.44; 95% CI 1.40-8.44, p = 0.01), PAS (OR 16.47; 95% CI 4.66-58.26, p < 0.01), and RPOC (OR 29.70; 95% CI 11.23-78.55, p < 0.01) was more in pregnant women with severe PPH. In the multivariate analysis for severe PPH, prior CS (OR 4.71; 95% CI 1.29-17.13, p = 0.02), major previa (OR 7.50; 95% CI 1.98-28.43, p < 0.01), and RPOC (OR 13.26; 95% CI 3.61-48.63, p < 0.01) were identified as risk factors.

CONCLUSIONS

Prior CS and PAS were identified as risk factors for RPOC in placenta previa and RPOC is closely associated with severe PPH. Therefore, a new strategy for RPOC in placenta previa is needed.

Managing patients with suspected postpartum retained products of conception using a novel sonographic classification

BACKGROUND

Suspicion of retained products of conception (RPOC) often arises after delivery and still poses a diagnostic and management challenge.

PURPOSE

To prospectively evaluate a sonographic classification for the management of patients with suspected RPOC after delivery.

MATERIAL AND METHODS

Based on grayscale and Doppler ultrasound parameters, patients were classified into high, moderate, or low probability of RPOC. For the low and moderate probability groups, an ultrasound follow-up at the end of the puerperium was recommended. For the high probability group, a follow-up examination was conducted 10-14 days after the first ultrasound, and patients with persistent high probability findings were referred for surgical intervention.

RESULTS

The sample was composed of 215 patients at risk of RPOC. Of these, 100, 93, and 22 patients were classified as having a low, moderate, or high probability of RPOC, respectively. Rates of RPOC were 55%, 2%, and 2% in the high, moderate, and low probability categories, respectively. When the categorization was based on the most recent ultrasound obtained during the puerperium, the adjusted RPOC prevalence rates were 71% in the high, 6% in the moderate, and 0% in the low probability groups.

CONCLUSION

This study confirms the effectiveness of our sonographic classification for managing patients with suspected RPOC after delivery. In all three categories, it is recommended to adhere to a conservative management protocol in clinically stable women until the end of the puerperium. This approach provides good predictability for RPOC and can reduce unnecessary surgical interventions.

The role of ultrasound imaging in the management of partial placental retention after third trimester livebirth

Objectives: To evaluate the impact of different ultrasound signs in the management and the role of ultrasound guidance in the surgical evacuation of partial placental tissue retention.Methods: This is an observational cohort study and retrospective case assessment of 82 patients with clinical symptoms of partial placental retention following a third trimester singleton livebirth between January 2013 and May 2019. The ultrasound signs were recorded using a standardized protocol and the outcome of the management strategy and the use of ultrasound guidance during any surgical procedure was evaluated.Results: Out of the 64 patients who had a vaginal birth, 25 (39.1%) had a manual removal of the placenta at delivery. Fifteen patients were confirmed as not having retained placental tissue and did not require further treatment. Four patients were referred after failed surgical management and four after failed conservative management. All surgical procedures were vacuum aspiration and forceps removal under continuous ultrasound guidance. A significantly lower gestational age at delivery (p < .05), shorter interval between delivery and ultrasound diagnosis (p < .05) and lower number of patients presenting with heavy bleeding was found in the conservative compared to the surgical management subgroups (p < .05). The incidence of feeding vessels was significantly (p < .05) higher in the surgical than in the conservative management subgroups and associated with increased myometrial vascularity. Six patients developed intra-uterine adhesions. In four of these cases, ultrasound examination showed a hyperechoic mass surrounded by normal myometrial vascularity and no feeding vessel.Conclusions: Ultrasound imaging accurately differentiated between patient with and without partial placental retention after third trimester livebirth. Ultrasound-guided vacuum aspiration is safe and efficient in these cases.

Ultrasound criteria for managing postpartum patients with suspicion of retention of conception products

Background

Retention of conception products is a common complication following delivery and remains a diagnostic and management challenge due to non-specific symptoms and ultrasound findings.

Purpose

To introduce a clinical approach for managing patients with suspected retained products of conception following delivery.

Material and Methods

The ultrasound examination included gray-scale and Doppler parameters which classified the patients into three groups: high, moderate, or low probability for retained products of conception. The same classification was used both to stratify individual risk for retained products of conception, as well as for counseling the appropriate management.

Results

The study included 66 patients. Retained products of conception was confirmed in 62%, 32% and 0% of the high, moderate and low probability groups, respectively. Additionally, each group was further divided according to the timing of the ultrasound examination: before or after 42 postpartum days. A significant increase, from 12% to 64%, in the positive predictive value was observed in the moderate probability group when the ultrasound was performed ≥ 42 days postpartum.

Conclusions

In the low probability group, no surgical intervention is recommended. When ultrasound findings are classified as high probability for retained products of conception, surgical evacuation of the uterine content is recommended. For clinically stable women with ultrasound findings consistent with moderate probability, ultrasound follow-up at the end of the puerperal period (42 days) is recommended. This approach may improve the sonographic prediction of retained products of conception and prevent unnecessary interventions.

Predictors of Postpartal Retained Products of Conception

BACKGROUND

Retention of products of conception (RPOC) following delivery is rare. Clinicians often have the impression that a high proportion of patients with sonographically suspected RPOC following surgery have a negative histopathology. Hence, we aimed to report our single-center experience with suspected RPOC and histopathological outcome after surgery.

PATIENTS AND METHODS

In this retrospective analysis, patients who underwent surgery due to suspected postpartum RPOC were analyzed for potential predictive clinical and sonographic parameters.

RESULTS

A total of 32 patients with histopathologically-confirmed RPOC were compared with 21 patients with a negative histopathological report for RPOC. Endometrial hyperechogenic mass and clinical parameters such as pain, fever and bleedings were not predictive for RPOC. Increased age (p=0.001) and vaginal delivery (p=0.040) were significantly associated with RPOC.

CONCLUSION

Clinical presentation alone is not predictive for RPOC. Vaginal delivery and younger age seem to be a risk factor and therefore have to be considered in patients with suspected RPOC.

Best predictors of grayscale ultrasound combined with color Doppler in the diagnosis of retained products of conception

OBJECTIVES

To determine the best predictors of the presence of retained products of conception (RPOC) on grayscale and color Doppler transvaginal sonographic examination.

METHODS

This was a retrospective study of 91 consecutive patients who underwent transvaginal sonography (TVS) with color Doppler to evaluate for the presence of RPOC. The images of TVS studies were reviewed by two radiologists in consensus blinded to the final outcome. Data on a number of variables including endometrial measurable mass and focal increased color vascularity were collected as predictors of RPOC. The patients' ages ranged from 17 to 48 years (mean, 31.8 ± 6.8) and gestational age from 5 to 24 weeks (mean, 9.2 ± 3.8). Thirty-six were confirmed as RPOC by dilatation and curettage (D&C) and pathology. Fifty-five were considered negative, 9 based on D&C results and 46 on clinical grounds.

RESULTS

Sensitivity, specificity, negative- and positive-predictive and accuracy values were 81% (CI: 68%-94%), 71% (CI: 59%-83%), 85% (CI: 74%-95%), 64% (CI: 50%-78%), and 75% (CI: 66%-84%) to detect RPOC when a mass was present. The corresponding numbers for the presence of focal color vascularity were 94% (CI: 87%-100%) (p = 0.07), 67% (CI: 55%-80%) (p > 0.05), 95% (CI: 88%-100%) (p = 0.1), 65% (CI: 52%-78%) (p > 0.05), and 78% (CI: 70%-87%) (p > 0.05). Of the patients with confirmed RPOC on pathology, five had focal increased vascularity and no massand none had a mass without focal increased vascularity.

CONCLUSION

An area of focal increased vascularity with or without a mass is the best predictor of the presence of RPOC.

Management of Asherman's syndrome

Intrauterine adhesions (IUA) or Asherman's syndrome is a multifaceted condition which is being diagnosed with increasing frequency. Although it usually occurs following curettage of the pregnant or recently pregnant uterus, any uterine surgery can lead to IUA. Most women with IUA have amenorrhoea or hypomenorrhoea, but some have normal menses. Those who have amenorrhoea may also have cyclic pelvic pain secondary to 'trapped' menses and the accompanying retrograde menstruation may lead to endometriosis. In addition to menstrual disorders, most women with IUA will present with infertility or recurrent spontaneous abortion. Over the last four decades hysteroscopy has become the standard method to diagnose and treat this condition. Various techniques for adhesiolysis and for prevention of scar reformation have been advocated. The most efficacious appears to be the use of miniature scissors for adhesiolysis and the placement of a balloon stent inside the uterus immediately after surgery. Post-operative oestrogen therapy is prescribed in order to stimulate endometrial regrowth. Follow-up studies to assure resolution of the IUA are mandatory before the patient attempts to conceive as is careful monitoring of pregnancies for cervical incompetence, placenta accreta and intrauterine growth restriction.

Postpartum curettage: An audit of 200 cases

AIM

To assess whether delivery details, clinical features at presentation and laboratory investigations could accurately predict the presence of retained products of conception (RPOC) following a postpartum curettage (PPC) and to assess the morbidity associated with this procedure.

METHODS

A retrospective chart review of patients who underwent a PPC at a tertiary referral hospital over a 5-year period.

RESULTS

Two hundred patients were included in the study and 50% of patients who had histological evaluation demonstrated retained product of conception. Mode of delivery, placental status at delivery and immediate postpartum haemorrhage was unrelated to final histology however, patients presenting with pelvic infection were significantly less likely to have RPOC, chi(2 )= 6.358 (P = 0.042). The sensitivity and specificity of ultrasound in detecting RPOC was 94% and 16%, respectively; the presence of an echogenic focus together with a thickened endometrium of more than 10 mm was the most accurate ultrasound feature of RPOC (positive predictive value 80%). Seventeen (8.5%) patients experienced major morbidity following curettage and 14 (7%) underwent a repeat procedure with further morbidity. Patients presenting with pelvic infection were more likely to experience postoperative morbidity.

CONCLUSION

A PPC has a low diagnostic yield and is associated with a significant complication rate. While the therapeutic benefit of this procedure is unclear, expectant management is appropriate especially in the presence of pelvic sepsis.

The sonographic and color Doppler features of retained products of conception

OBJECTIVE

The purpose of this study was to identify the sonographic features of retained products of conception (RPOCs).

METHODS

Cases of clinically suspected RPOCs referred for pelvic sonography between September 1994 and July 2001 were identified. Patient age, indication, gestational age at delivery, and days postpartum were recorded and sonographic findings were reviewed. Outcomes were determined from medical records and pathology reports.

RESULTS

One hundred sixty-three cases were identified. Indications for pelvic sonography included vaginal bleeding in 82 (50%), pelvic pain in 77 (47%), and fever in 55 (34%). Gestational age at delivery ranged from 14 to 43 weeks (mean, 37 weeks), and the sonographic examination was performed from 0 to 95 days postpartum (mean, 21 days). Thirty-six patients underwent surgical intervention, and 28 of these had RPOCs. The remaining 127 patients were followed clinically. An endometrial mass was the most sensitive (79%) and specific (89%) sonographic feature for RPOCs. The isolated finding of either complex fluid in the endometrial canal or a thick endometrium measuring greater than 10 mm had low sensitivity, specificity, and negative and positive predictive values. None of the patients with RPOCs had normal sonographic findings. The absence of an endometrial mass or complex fluid and an endometrial thickness of less than 10 mm were considered normal findings. Color Doppler flow was detected in the endometrium somewhat more often when RPOCs were present than in the absence of RPOCs (75% versus 40%).

CONCLUSIONS

An endometrial mass is the most sensitive finding for RPOCs. If no mass or endometrial fluid is seen and the endometrial thickness is less than 10 mm, RPOCs are extremely unlikely. The absence of blood flow does not exclude the diagnosis of RPOCs.

Sonographic versus clinical evaluation as predictors of residual trophoblastic tissue

BACKGROUND

The study aims to compare the diagnostic accuracy of sonographic evaluation versus clinical estimation in women suspected to have retained trophoblastic fragments.

METHODS

The study group consisted of 68 consecutive patients admitted to our department due to suspected residual trophoblastic tissue. Each woman underwent ultrasound and physical examination by expert clinicians. The clinicians performing the physical examination were not informed of the sonographic findings, and vice versa.

RESULTS

Patients were divided into three subgroups: clinical suspicion only of residual trophoblastic tissue (n = 8), sonographic suspicion only (n = 44) and combined sonographic and clinical suspicion of residual trophoblastic tissue (n = 16). In the latter group, in 14 out of 16 women (87.5%) retained trophoblastic tissue was confirmed by histological examination, a significantly higher rate compared to ultrasonographic (45.5%, P < 0.002) or clinical suspicion only (62.5%, P = 0.07). The specificity and positive predictive value of the clinical examination were significantly higher compared to ultrasonographic evaluation (P < 0.05), while the sensitivity of the ultrasonographic evaluation was higher than the clinical estimation (P < 0.05). There was no statistically significant difference in the negative predictive value or in diagnostic accuracy between the two methods.

CONCLUSIONS

Based on our current experience, it seems that the combination of both clinical and ultrasonographic evaluation is recommended before uterine curettage is performed, thus lowering the rate of unnecessary invasive procedures.

Color Doppler and gray-scale ultrasound evaluation of the postpartum uterus

OBJECTIVES

To evaluate the color Doppler and gray-scale sonographic appearance of the uterus after pregnancy, with special attention to the occurrence of areas of enhanced vascularity and placental remnants.

PATIENTS AND METHODS

Cross-sectional observational study involving 385 consecutive women presenting at their first visit after pregnancy. The uterus was evaluated using ultrasound with color Doppler. In the presence of placental remnants, blood was sampled for measurement of beta human chorionic gonadotropin (beta hCG), hemoglobin (Hb) and infectious parameters. If indicated, a dilatation and curettage was performed.

RESULTS

In 8.3% of women, areas of enhanced vascularity were detected with color Doppler examination. Most cases (68.9%) were focal areas of one or more vessels. In 2.6% of patients abnormal vascularity extended over a large area of the whole myometrium. In 6.75% of cases, placental remnants were detected. In 46% of these, blood sampling revealed beta hCG levels below 30 mIU/mL; serological infection parameters and Hb concentration were within the normal range.

CONCLUSIONS

Areas of enhanced vascularity of the uterus, ranging from a focal vascular pedicle to a larger area of the myometrium, are relatively common after pregnancy. They are predominantly seen in the presence of placental remnants, in the early postpartum period and after instrumental or manual delivery of the placenta. There are no clear risk factors for retained placental tissue, besides the history of blood transfusion in the early postpartum, and perhaps multigravidity. Serology is of little help in the diagnosis of retained gestational products. The knowledge of the ultrasound and color Doppler features of the uterus after pregnancy may prove of practical value for the management of abnormal uterine bleeding in the postpartum period.