Sonographic diagnosis of partial versus complete molar pregnancy: A reappraisal

The diagnostic value and accuracy of ultrasound in diagnosing hydatidiform mole: A systematic review and meta-analysis of the literature

INTRODUCTION

Hydatidiform moles are the most common type of gestational trophoblastic disease. Internationally the incidence of hydatidiform moles is 1-2:1000 pregnancies. Early detection of women with hydatidiform moles is preferential, as these women are at a higher risk of developing other gestational trophoblastic disease. Despite Ultrasound being the most common modality used to diagnose hydatidiform moles, its diagnostic value and accuracy throughout all trimesters remains uncertain. Thus, the aim of this review was to explore and evaluate the diagnostic value and accuracy of Ultrasound in diagnosing hydatidiform mole throughout all trimesters of pregnancy.

METHODS

The databases MEDLINE and CINAHL were searched between 2004 and 2021. Included studies were quality assessed using the Mixed Methods Appraisal Tool.

RESULTS

A total of 8 studies were included. The narrative synthesis identified four themes: Misdiagnosis, Complete and Partial molar pregnancy, Operator dependency and Gestational age. The meta-analysis highlighted although the sensitivity of ultrasound for diagnosing hydatidiform moles is relatively low at 52.2%, the specificity was high at 92.6%.

CONCLUSION

While histological examination remains the gold standard for detecting hydatidiform moles, our review made evident that ultrasound is a beneficial diagnostic tool in the detection of Hydatidiform moles, especially alongside other diagnostic investigations. This review has highlighted and collated the main barriers and facilitators to diagnosing hydatidiform moles using ultrasound.

IMPLICATION FOR PRACTICE

Findings suggest that although sonographic detection of hydatidiform moles remains a diagnostic challenge, seeking a second opinion or repeating scans before making a final diagnosis should be embedded into clinical practice.

Obstetrical and oncological outcomes of twin pregnancies with hydatidiform mole and coexisting fetus

OBJECTIVE

To evaluate the obstetrical and oncological progression of twin pregnancies with hydatidiform mole coexisting fetus (HMCF).

MATERIALS AND METHODS

Using a retrospective method based on patients from the Women's Hospital, Zhejiang University School of Medicine database between January 1990 and October 2020, 17 patients were histologically confirmed as having HMCF, and the patients' prenatal diagnosis, outcomes and development of gestational trophoblastic neoplasia (GTN) were reviewed.

RESULTS

Among these 17 cases, 11 (64.71%) cases were complete hydatidiform mole coexisting fetus (CHMCF), and 6 (35.29%) cases were partial hydatidiform mole coexisting fetus (PHMCF). The gestational age at diagnosis of CHMCF was significantly earlier than that of PHMCF [9 (8-24) vs. 18 (11-32) weeks, respectively, P < 0.05]. The live birth rate of PHMCF was slightly higher than that of CHMCF (33.33%; 18.18%), but this difference was not statistically significant. The overall rate of GTN incidence of HMCF was 47.06% (8/17), and the GTN rates of PHMCF and CHMCF were 33.33% (2/6) and 54.55% (6/11), respectively. There was no significant difference in the GTN rate between patients who chose to continue pregnancy and those who terminated pregnancy before 24 weeks of gestation. The GTN rate of patients with term delivery was not significantly higher than that of preterm delivery.

CONCLUSION

In HMCF cases, the incidence rate of CHMCF was higher than that of PHMCF, and PHMCF is more difficult to diagnose in the early stage. Continuing pregnancy does not increase the risk of GTN compared to terminating pregnancy. In cases of HMCF, when the fetal karyotype is normal and maternal complications are controlled, it is safe to continue the pregnancy and extend it to term.

Complete Hydatidiform Mole and Coexisting Fetus With Gastroschisis: A Case Report Highlighting the Importance of Diagnostic Genotyping

Twin pregnancy with a complete hydatidiform mole and a coexisting fetus (CHMCF) is an extremely rare occurrence, described only by a handful of published series and cases reports. The majority of the literature on CHMCF examines prenatal care and follow-up in relation to the increased risk of gestational trophoblastic neoplasia (GTN). At present, few reports elaborate on the diagnostic process and differential diagnosis, especially in the context of recent molecular advances in risk stratification for GTN. Here, we describe the first known case of a CHMCF with gastroschisis with liveborn delivery at 35 weeks gestation. This report aims to review the pre- and postnatal differential diagnosis and discuss recent updates on the importance of ancillary studies in the diagnosis of gestational trophoblastic disease.

ACR Appropriateness Criteria® Gestational Trophoblastic Disease

Gestational trophoblastic disease (GTD), a rare complication of pregnancy, includes both benign and malignant forms, the latter collectively referred to as gestational trophoblastic neoplasia (GTN). When metastatic, the lungs are the most common site of initial spread. Beta-human chorionic gonadotropin, elaborated to some extent by all forms of GTD, is useful in facilitating disease detection, diagnosis, monitoring treatment response, and follow-up. Imaging evaluation depends on whether GTD manifests in one of its benign forms or whether it has progressed to GTN. Transabdominal and transvaginal ultrasound with duplex Doppler evaluation of the pelvis are usually appropriate diagnostic procedures in either of these circumstances, and in posttreatment surveillance. The appropriateness of more extensive imaging remains dependent on a diagnosis of GTN and on other factors. The use of imaging to assess complications, typically hemorrhagic, should be guided by the location of clinical signs and symptoms. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Decreasing incidence of registered hydatidiform moles in Denmark 1999-2014

Incidences of hydatidiform mole (HM) registered in European countries varies from 0.98/1000 to 2.17/1000 deliveries, while higher incidences have been reported in other parts of the world. We calculated the incidence by selecting data on HMs classified as ”first”, “second” and “third” from 01.01.1999 to 31.12.2014 registered in the Danish Pathology Registry, which we previously showed to be the most complete data source on the number of HMs in Denmark. In the study period, 1976 first HMs were registered; 1080 (55%) were classified as PHMs (partial HMs) and 896 (45%) as NPHMs (HMs not registered as PHMs). The average incidence of HM was 1.98/1000 deliveries. The incidence of PHM was 1.08/1000 deliveries and the incidence of NPHM was 0.90/1000 deliveries. Forty HMs were registered as second HMs; 85% (34/40) were of the same histopathological type as the first HM. The registered incidence of HM decreased from 2.55/1000 deliveries in 1999 to 1.61/1000 deliveries in 2014 (p < 0.005). The decrease in the incidence of HM was identical with a decrease in the incidence of PHM. New medical practices such as medical abortion and only forwarding selected pregnancy products for histopathologic examination may cause a declining number of HMs registered.

An Invasive Molar Pregnancy: A Case Report With Associated Imaging

Human chorionic gonadotropin is generally used as a biomarker to identify invasive molar pregnancy. The extent of the disease (e.g., its staging) has not, however, relied on its sonographic description. A case is presented that can illustrate some diagnostically useful sonographic features of three-dimensional transvaginal sonography for this condition. The clinical imaging of this case initially suggested it to be a benign hydatidiform mole but ultimately was diagnosed as an invasive molar pregnancy, with human chorionic gonadotropin monitoring. Clinical imaging was used to help manage this patient, with the demonstration of trophoblastic invasion of the uterine wall. Although two-dimensional sonography is commonly used to diagnose molar pregnancy, three-dimensional sonography may offer a clinical advantage for the management of invasive molar pregnancy, which can occur in 15% of benign hydatidiform molar pregnancies.

Diagnosis and outcome of hydatidiform moles in missed-miscarriage: a cohort-study, systematic review and meta-analysis

OBJECTIVE

To evaluate the ultrasound diagnostic rates of complete hydatidiform moles (CHM) and partial hydatidiform moles (PHM) in women presenting with a missed miscarriage, the clinical complications at diagnosis and the risk of gestational trophoblastic neoplasia (GTN) after surgical evacuation and to compare our findings with those of the published literature by completing a systematic review and meta-analysis STUDY DESIGN: Retrospective review of the data of 295 women diagnosed with a histologically confirmed hydatidiform moles (HM) over a 15-year period, including 128 CHM and 167 PHM. All women were referred to a regional specialist centre for follow-up and further management. An electronic search of PubMed, Google Scholar and MEDLINE was performed for studies published between September 1973 and September 2017 reporting on the early ultrasound diagnosis of hydatidiform mole. Only cohort studies which provided ultrasound data confirmed by histopathology were included.

RESULTS

In the cohort study, ultrasound imaging diagnosed a significantly (p < 0.001) higher number of CHM (95/128 (74.2%) than PHM (68/167 (40.7%). Ovarian theca lutea cysts were observed in three CHM and one PHM. There were no cases of pre-eclampsia or thyrotoxicosis at the time of diagnosis. Maternal serum β-human chorionic gonadotrophin levels were abnormally low (< 0.5 MoM) in 5/51 (10%) CHM and 23/43 (53%) PHM and abnormally high (> 2.0 MoM) in 20/51 (39%) CHM and 2/43 (5%) PHM. Seventeen (12.3%) CHM and two (1.4%) PHM developed a GTN requiring treatment. In the literature the proportion of histologically diagnosed HM, suspected on ultrasound in early pregnancy, ranged between 34.2 and 90.2% for HM, 57.8 and 95% for CHM and 17.6 and 51.6% for PHM. The meta-analysis indicated substantial heterogeneity in the overall ultrasound diagnosis of HM and in the differential diagnosis between CHM and PHM.

CONCLUSION(S)

As around a third of CHM and two thirds of PHM are not diagnosed on ultrasound in cases of missed miscarriage, histopathological examination of all products of conception in case of early pregnancy failure is essential to detect molar changes. This is particularly important for the management of women with CHM who have a higher risk of developing a GTN.

Ultrasound diagnosis of complete and partial hydatidiform moles in early pregnancy failure: An inter-observer study

We evaluated the accuracy of the ultrasound signs suggestive of complete hydatidiform mole (CHM) and partial hydatidiform mole (PHM) in a cohort of women with histologically confirmed hydatidiform mole (HM) who presented with early pregnancy failure, including 103 CHM and 95 PHM for which ultrasound images were available. The accuracy of the differential diagnosis was significantly (p < 0.001) greater during secondary examination of ultrasound images compared with the original primary ultrasound examination. The interobserver agreement analysis indicated only a fair to moderate agreement between the two examinations (kappa value 0.41; 95% CI 0.29-0.53). Most HM present as early pregnancy failure and identification of early ultrasound signs can improve the differential diagnosis between CHM and PHM.

A Pictorial Ultrasound Essay of Gestational Trophoblastic Disease

Gestational trophoblastic disease (GTD) includes a wide variety of clinical and histopathologic entities that require prompt identification and definition by the integration of clinical, laboratory, and imaging data. Recently, the role of grayscale ultrasound and spectral and power/color Doppler techniques has become pivotal in the diagnosis, staging, and management of GTD, thanks to both technical improvements and the growing expertise of dedicated operators. The aim of this essay is to summarize the most recent data on the ultrasound and Doppler findings of GTD and to provide a pictorial overview, including useful prognostic and therapeutic implications for clinical practice.

Termination of a partial hydatidiform mole and coexisting fetus: A case report

BACKGROUND

We describe the treatment strategy for a patient who was found to have a partial hydatidiform mole and coexisting fetus (PHMCF) during the second trimester. The patient was a 38-year-old Chinese woman who had become pregnant following in vitro fertilization and embryo transplantation. We wanted to determine the safest therapeutic strategy to terminate the PHMCF during the second trimester.

CASE SUMMARY

In this case, we present a patient who was found to have a PHMCF complicated with serious continuous vaginal bleeding and pre-eclampsia during the second trimester. After careful evaluation, the pregnancy was considered to be unsustainable and was terminated via caesarean section (CS). An infant with weak vital signs and a partially cystic placenta measuring 110 mm × 95 mm × 35 mm were delivered by CS. The patient was discharged after 4 d. The serum levels of β-human chorionic gonadotropin decreased to within a normal range 5 wk after the operation, and no evidence of persistent trophoblastic disease or lung metastases was noticed at the 6-mo follow-up.

CONCLUSION

CS termination of PHMCF during the second trimester may be a relatively safe therapeutic strategy.

Ultrasound of the First Trimester

Ultrasound is the imaging study of choice for detection and full characterization of early pregnancies based on its accuracy, low cost, safety profile, and abundant availability. This article reviews the goals and utility of first-trimester ultrasound in gestation localization, viability determination, and abnormal pregnancies, including ectopic implantation, retained products, and molar pregnancy.

Hydatidiform mole: validity of the registration in the Danish National Patient Registry, the Danish Cancer Registry, and the Danish Pathology Registry 1999-2009

Purpose

To examine the validity of registration of hydatidiform mole (HM) in the Danish National Patient Registry (NPR), the Danish Cancer Registry (DCR), and the Danish Pathology Registry (DPR).

Patients and methods

We selected women registered with a first-time HM code in NPR, DCR, and DPR from 1999 to 2009. We found most women registered in DPR. For a random sample of women registered in DPR, the coding was validated by comparing with the pathology report. Completeness and positive predictive value (PPV) of registration with an HM code in NPR and DCR were calculated using DPR as the reference. Details of women registered in NPR or DCR, but not in DPR, were scrutinized.

Results

In NPR and DPR, 1,520 women were identified in total; 1,057 (70%) were found in both registries, 65 (4%) only in NPR, and 398 (26%) only in DPR. In DCR and DPR, 1,498 women were identified in total; 1,174 (78%) in both registries, 47 (3%) only in DCR, and 277 (19%) only in DPR. For 149/150 randomly selected women registered with an HM code in DPR (99%), the pathology report was consistent with the diagnosis of HM. Completeness of NPR was 73% (95% CI: 70%–75%) and PPV was 94% (95% CI: 93%–95%). Completeness of DCR was 72% (95% CI: 69%–75%) in 1999–2003 and 90% (95% CI: 87%–92%) in 2004–2009. PPV of DCR was 96% (95% CI: 95%–97%) throughout the period.

Conclusion

Validation of registry data is important before using these. For research on the number of HMs in Denmark, DPR is the most valid data source. NPR and DCR appear to be equally valid before 2004. However, for research after 2004, DCR should be preferred rather than NPR.

Ultrasound diagnosis of molar pregnancy

Introduction

The primary aims of this study were to establish what proportion of ultrasonically suspected molar pregnancies were proven on histological examination and what proportion of histologically diagnosed molar pregnancies were identified by ultrasound pre-operatively. The secondary aim was to review the features of these scans to help identify criteria that may improve ultrasound diagnosis.

Methods

This was a retrospective observational study conducted in the Early Pregnancy Unit at King's College Hospital London over an 11-year period. Cases of ultrasonically suspected molar pregnancy or other gestational trophoblastic disease were identified and compared with the final histopathological diagnosis. In addition, cases which were diagnosed on histopathology that were not suspected on ultrasound were also examined. In discrepant cases, the images were reviewed unblinded by two senior sonographers. Statistical analysis for likelihood ratio and post-test probabilities was performed.

Results

One hundred eighty-two women had gestational trophoblastic disease suspected on ultrasound examination (1:360, 0.3%); 106/182 (58.2%, 95% CI 51.0 to 65.2%) had histologically confirmed gestational trophoblastic disease. The likelihood ratio for gestational trophoblastic disease after a positive ultrasound was 607.27, with a post-test probability of 0.628.The sensitivity of ultrasound for gestational trophoblastic disease was 70.7% (95% CI 62.9% to 77.4%) with an estimated specificity of 99.88% (95% CI 99.85% to 99.91%); 102/143 (71.3%, 95% CI 63.4 to 78.1%) molar pregnancies were suspected on pre-op ultrasound; 60/68 (88.2%, 95% CI 78.2 to 94.2%) of complete moles were suspected on pre-op ultrasound, compared with 42/75 (56.0%, 95% CI 44.7 to 66.7%) of partial moles. On retrospective review of the pre-op ultrasound images, there were cases that could have been suspected prior to surgery.

Conclusion

Detecting molar pregnancy by ultrasound remains a diagnostic challenge, particularly for partial moles. These data suggest that there has been an increase in both the predictive value and the sensitivity of ultrasound over time, with a high LR and post-test probability; however, the diagnostic criteria remain ill-defined and could be improved.

A 34-Week Size Uterus with a Complete Hydatidiform Mole: Hook Effect and Severe Anemia with No Vaginal Bleeding

Complete hydatidiform mole is an abnormal pregnancy that usually presents with vaginal bleeding and markedly elevated serum ß-hCG levels. We report a rare case of complete hydatidiform mole occurring in a 16-year-old nulligravid who presented with a 34-week size uterus and a relatively low serum ß-hCG level (722 IU/L)-likely related to the "hook effect"-and severe anemia (hemoglobin: 6.1 g/dL) despite the absence of vaginal bleeding. She also reported right flank pain and was diagnosed with moderate right hydronephrosis owing to the compression exerted by the enlarged uterus on the right ureter. The patient received a total of 6 units of packed red blood cells and was managed by dilation and evacuation followed by serial monitoring of serum ß-hCG levels. Therefore, complete mole can present with symptoms related to an enlarged uterus and severe anemia before the occurrence of vaginal bleeding. It is also important to note that a negative urine pregnancy test or relatively low serum ß-hCG level should prompt repeating the measurement on diluted sample to prevent the "hook effect."

Challenges in the Routine Praxis Diagnosis of Hydatidiform Mole: a Tertiary Health Center Experience

Introduction:

Hydatidiform moles (HM), presenting as complete (CHM) and partial (PHM) form, are rare pregnancy disorder. Diagnosis is based on clinical presentation, ultrasound imaging findings and pathological examination of products of conception. Protein p57, encoded by CKDN1C gene, is paternally imprinted and maternally expressed gene and provides quick insight in genetic basis of HM and allows distinction of CHM from all other conceptions. compare the preevacuational and pathohistological diagnosis with outcome of p57 immunostaining.

Material and methods:

All cases of HM diagnosed between January 2011 and December 2015 were included in this research. Maternal age, gestational age and input diagnosis data were recored. p57 immunostaining was performed in order to evaluate the diagnosis based on tissue slides examination.

Results:

There were 198 cases of histologically confirmed HM, 185 PHM, 12 CHM and one case of undefined HM. Mean maternal age in the CHM group was 24,7 and in the PHM group 26,9 years, with no significant differences among these two groups (p=0,27). For CHM mean gestational age was estimated at eight and for PHM 9,2 gestational weeks. Pregnant woman older than 40 years present significant earlier compared with younger woman (p<0,01), and those younger than 20 years tend to present at the beginning of the second trimester more often than older women (p<0,05). In the CHM group, 9 (75%) input diagnoses were mola in obs, and 3 (25%) of them were signed as abortion, unlike the PHM where 126 (67%) were qualified as abortion, 35 (19%) as blighted ovum, and 26 (14%) were suggestive for molar pregnancy. p57 immunostaining results confirmed all pathohistological diagnosis of CHM whereas 8% of PHM demonstrated divergent p57 expression.

Conclusion:

PHM, compared with CHM, represent a greater diagnostic challenge for both gynecologist and pathologist even when presenting in more advanced pregnancies.