Outcome of non-visualization of fetal gallbladder on second-trimester ultrasound: cohort study and systematic review of literature

Prenatal genetic detection in foetus with gallbladder size anomalies: cohort study and systematic review of the literature

OBJECTIVES

The aim of the study was to evaluate the detection rate of genetic abnormalities in cases of foetal gallbladder (FGB) size abnormalities to determine whether these abnormalities justify prenatal diagnosis.

METHODS

Two hundred and twenty-seven foetuses with gallbladder (GB) size anomalies who underwent prenatal diagnosis between January 2015 and June 2024 were included in the study. All these patients underwent chromosomal microarray and/or karyotyping, and 37 cases also underwent whole exome sequencing (WES). Two hundred and eight cases were followed up for postnatal outcomes. Then, we reviewed the literature of FGB anomalies cases with confirmed chromosomal results.

RESULTS

The study included 227 foetuses, comprising 60 cases with isolated GB size anomalies and 167 cases with non-isolated GB size anomalies. Non-isolated GB size anomalies were associated with findings such as hyperechogenic bowel, ventriculomegaly, foetal growth restriction (FGR), cardiac anomalies, renal dysplasia and single umbilical artery. The overall diagnostic yield of genetic tests was 10.57% (24/227). Aneuploidies were identified in seven foetuses. Pathogenic/likely pathogenic copy number variations (CNVs) were found in nine foetuses, and α0-thalassemia in five foetuses. Additionally, three pathogenic single-nucleotide variants (SNVs) were detected through WES. Foetuses with non-isolated GB size anomalies showed a higher rate of detecting genetic abnormalities compared to those with isolated GB size anomalies, with a significant difference in statistical analysis (13.2% vs. 3.3%, p = .033, Chi-square test). A total of eight studies, involving 407 cases met the criteria for inclusion in the systematic review. Overall, 28 foetuses were identified to have chromosomal abnormalities (6.9%, 28/407).

CONCLUSIONS

This study indicates that parents of foetuses with GB size anomalies should be informed about the potential for aneuploidy, pathogenic CNVs and SNVs, and genetic testing should be recommended in cases of non-isolated foetal GB size anomalies.

Revisiting Ultrasound of Fetal Abdominal Cysts; the Common, the Uncommon and the Rare: A Pictorial Review

Fetal abdominal cysts are rare. The significance of antenatally discovered abdominal cysts can range from an innocuous finding to serious conditions needing surgery. It is often difficult to arrive at a correct diagnosis based on ultrasonography, as different types of cysts can have similar appearances. A more specific diagnosis is possible if fetal sex, age at appearance, location of the cyst, shape and appearance of the walls, and contents are considered. This review presents an extensive spectrum of fetal abdominal cysts. The common as well as the very rare causes that have only a few reports are discussed. Ultrasound images of confirmed cases are also presented. An algorithmic approach that enables a more specific diagnosis in many cases has been developed.

Outcomes of pregnancies diagnosed with absent or abnormal fetal gallbladder in a tertiary center

OBJECTIVE

The objective of this study was to investigate the ultrasonographic characteristics and outcomes of fetuses with atypical and non-visualized fetal gallbladder in our tertiary care hospital.

METHODS

A retrospective analysis was conducted on cases in which the fetal gallbladder was not visualized or exhibited atypical characteristics at our institution over a four-year period. The patients were divided into two groups: absent gallbladder and atypical gallbladder. The groups with isolated and additional anomalies were analyzed according to their ante- and postnatal characteristics.

RESULTS

The study comprised 78 patients (37 absent, 41 atypical gallbladder). In the isolated fetal absence of gallbladder group, the gallbladder was visualized in three of 13 patients during antenatal ultrasonographic follow-up and in half of the remaining 10 patients during postnatal follow-up. In the postnatal period, five newborns with absent isolated gallbladder are being followed up with suspicion of biliary atresia and isolated gallbladder agenesis. In the absence of a gallbladder with an additional anomaly group, 58% of fetuses died during the intrauterine and neonatal period. Fetuses in the isolated atypical gallbladder group are being followed as healthy after birth. Pregnancies with atypical gallbladder appearance and additional anomalies resulted in 33% neonatal death, 12% intrauterine demise, and 25% termination of pregnancy.

CONCLUSION

In instances where the fetal gallbladder is not consistently discernible, it is imperative to exercise caution with regard to the possibility of biliary atresia. In the event that the fetal gallbladder exhibits unusual characteristics, a meticulous examination for the presence of additional anomalies is recommended.

Transfer learning method for prenatal ultrasound diagnosis of biliary atresia

Biliary atresia (BA) is a rare and severe congenital disorder with a significant challenge for prenatal diagnosis. This study, registered at the Chinese Clinical Trial Registry (ChiCTR2200059705), aimed to develop an intelligent model to aid in the prenatal diagnosis of BA. To develop and evaluate this model, fetuses from 20 hospitals across China and infants sourced from public database were collected. The transfer-learning model (TLM) demonstrated superior diagnostic performance compared to the basic deep-learning model, with higher area under the curves of 0.906 (95%CI: 0.872-0.940) vs 0.793 (0.743-0.843), 0.914 (0.875-0.953) vs 0.790 (0.727-0.853), and 0.907 (0.869-0.945) vs 0.880 (0.838-0.922) for the three independent test cohorts. Furthermore, when aided by the TLM, diagnostic accuracy surpassed that of individual sonologists alone. The TLM achieved satisfactory performance in predicting fetal BA, providing a low-cost, easily accessible, and accurate diagnostic tool for this condition, making it an effective aid in clinical practice.

Postnatal Outcome After Ultrasound Findings of an Abnormal Fetal Gallbladder: A Systematic Review and Meta-Analysis

OBJECTIVE

To describe postnatal outcome following the prenatal diagnosis of an abnormal fetal gallbladder.

METHODS

We conducted a systematic review of studies from January 1980 to January 2023 that described FGB abnormalities, which included agenesis or non-visualisation, abnormal content presence of sludge, abnormal shape or size and abnormal position, and postnatal outcome to determine the association with pathology.

RESULTS

In 51 studies, 842 fetuses had abnormal FGB. Non-visualisation of the FGB was the most common diagnosis (521 fetuses, mean gestational age 21.6 weeks, range 14-29). The FGB was subsequently visualised prenatally in 128 out of 521 cases (24.6%; 95% CI, 20.9%-28.3%). Of the 393 cases with persistent FGB non-visualisation (75.4%; 95% CI, 71.7-79.1), 48 cases (12.2%; 95% CI, 9.0-15.5) underwent termination of pregnancy (TOP) with FGB agenesis confirmed in 16 out of 26 fetuses that had a postmortem examination (61.5%; 95% CI, 42.8-80.2). After excluding cases with missing outcomes (n = 121), postnatal ultrasound was performed in 82.4% of cases with persistent non-visualised FGB (224/272; 95% CI, 77.8%-86.9%). The gallbladder was not visualised in 63.4% (142/224; 95% CI, 57.1-69.7), confirming GB agenesis. This was an isolated finding in 41.1% of cases (92/224; 95% CI, 34.6-47.5). Of 272 known outcomes, biliary atresia, cystic fibrosis, and structural or chromosomal abnormalities were diagnosed in 8.5% (n = 23), 12.5% (n = 34), 18.0% (n = 49) and 6.3% (n = 17) cases, respectively. The sensitivity (true positive rate) of ultrasound for GB agenesis in fetuses with persistently non-visualised FGB was 58.1% (158/272; 95% CI, 52.2%-64.0%). Fetal gallbladder stones/sludge were described in 100 fetuses mainly in the third trimester of pregnancy (mean gestational age 33.8 weeks). Resolution of postnatally followed up cases occurred in around one-third of the cases (37.3%) within 1 month after birth. There was a low reported association with severe conditions (2%).

CONCLUSIONS

This systematic review and meta-analysis found that when the fetal gallbladder was absent in mid-trimester, it was visualised in subsequent fetal ultrasound examinations in around 25% of cases. If persistently absent on prenatal ultrasound, the confirmed rate of GB agenesis was around 50%, with the neonates having biliary atresia, cystic fibrosis, or structural abnormalities. Because of the association with severe conditions, if persistent FGB agenesis is suspected, prenatal diagnosis should be offered. FGB abnormalities such as stones/sludge tended to resolve by 1 year of age with around half of all cases resolving by 1 month postnatal.

Prediction of Fetal Biliary Atresia Based on Second and Third-Trimester Ultrasound Characteristics

OBJECTIVE

 To explore the diagnostic performance of prenatal ultrasound in the prediction of biliary atresia (BA).

METHODS

 We prospectively collected cases of suspected biliary abnormalities in the 2^nd trimester of pregnancy and performed a series (at least 3) of prenatal ultrasound examinations in the 2^nd and 3^rd trimester. The presence of the gallbladder was examined each time, and its size and shape were assessed if the gallbladder was visible. The existence of other abnormalities was carefully evaluated. Neonatal ultrasound examination was conducted within 1 month after birth, and clinical data were followed-up for 6 months after birth.

RESULTS

 Among the 41 895 patients, 298 were suspected to have biliary abnormalities, while 82 patients were excluded due to loss to follow-up or induced labor caused by other abnormalities. A total of 216 patients were included in this study, and 15 were diagnosed with BA. We summarized the ultrasound findings of the gallbladders and defined a high-risk gallbladder for the prenatal diagnosis of BA. This was demonstrated to have the best diagnostic performance as a single parameter, with an area under the curve of 0.914 (95 %CI: 0.869-0.948). In addition, higher incidences of biliary cysts, right hepatic artery dilation, echogenic bowel, and ascites were observed in BA fetuses. Logistic regression analysis showed that the combination of 5 parameters had better diagnostic performance, with an area under the curve of 0.995 (95 %CI: 0.973-0.999).

CONCLUSION

 The fetal gallbladder was found to be a critical feature for the identification of BA. Concomitant abnormalities could be helpful to improve the accuracy of the diagnosis.

Dysmorphic Gallbladder Found on Prenatal Ultrasound as a Hint for Biliary Atresia

Biliary atresia (BA) is a rare but devastating cholangiopathy. We report a case series of dysmorphic gallbladders detected during prenatal ultrasound, which were confirmed as BA after birth. We present the prenatal ultrasound findings as well as integral follow-up, with an aim to raise awareness regarding the association between BA and dysmorphic gallbladder. Although this dysmorphic gallbladder is a strong hint for BA, it is also important to search for other related sonographic features, such as the presence of microcysts at the hepatic hilum, dilated right hepatic artery, and seroperitoneum, which may provide more evidence for the diagnosis of BA.

Anomalies of the fetal gallbladder: pre-and postnatal correlations

The gallbladder is not part of the standard survey of a fetus during obstetrical ultrasound. Yet, some anomalies can be detected. Most are clinically benign, but some are features of or associated with more serious complications. Biliary atresia constitutes the diagnosis with the worst prognosis. Its in utero diagnosis is difficult. Still, markers do exist and should be searched for. Knowledge of the normal appearances, variants and abnormalities of the gallbladder contributes to proper management. Any suspicion should lead to meticulous postnatal workup. Pre- or postnatal magnetic resonance imaging can provide additional information in select cases.

Improving prenatal detection of abdominal supraumbilical anomalies: The sonographic examination of fetal anechoic spaces of upper abdomen revisited

Visualization of the axial plane of the fetal abdomen is mandatory to obtain abdominal biometry in the assessment of fetal growth in the second and third trimesters. The main anatomic landmarks that must be identified in this view include the fetal stomach and the intrahepatic portion of the umbilical vein, which are easily identifiable as they appear anechoic on ultrasound. The gallbladder is the other prominent anechoic structure in this plane. Focused study of the morphological characteristics of, and spatial relationship among, these three anechoic spaces is a simple technique to detect anomalies involving fetal upper abdominal organs. In this review, the sonographic features of those conditions that can be detected using this technique, which was termed the Fetal Examination of the Anechoic Spaces of upper abdomen Technique (FEAST), are classified and illustrated.

A Spectrum of Ultrasound and MR Imaging of Fetal Gastrointestinal Abnormalities: Part 2 Anorectal Malformation, Liver, and Abdominal Wall Anomalies

Ultrasound (US) and magnetic resonance imaging (MRI) are two modalities for diagnosing fetal gastrointestinal (GI) anomalies. Ultrasound (US) is the modality of choice. MRI can be used as a complementary method. Despite its expanding utilization in central nervous system (CNS) fetal malformation, MRI has not yet been established for evaluation of fetal GI abnormalities. Therefore, more attention should be paid to the clinical implications of MRI investigations following screening by US.

Pregnancy Outcomes of Non-Visualization of the Fetal Gallbladder from a Chinese Tertiary Single Centre and Literature Review

Objection: To explore the clinical features and prognosis of non-visualization of the fetal gallbladder (NVFGB). Methods: Sixty-five cases diagnosed with NVFGB in the Peking University First Hospital were collected retrospectively from January 2019 to December 2020. Results: Forty-nine cases were successfully followed up. Among them, the gallbladder of 21 fetuses (42.9%) was present in the later pregnancy. In the rest 28 cases (57.1%), the gallbladders were absent during the whole pregnancy. Eleven of twenty-eight fetuses (39.3%) with NVFGB were complicated with other structural anomalies. In the remaining 17 cases of isolated NVFGB (60.7%) during the whole pregnancy, there was one case of congenital biliary atresia, three cases of a small gallbladder, one case of gallstone and one case of the gallbladder with several septa inside. A total of nine cases (18.4%) underwent prenatal diagnosis, four of which revealed abnormal copy number variant (CNV) results. Conclusion: Nearly half of NVFGB could be noted during the later pregnancy. The persistent NVFGB during the pregnancy has a higher risk to complicate gallbladder abnormality, other structural anomalies and abnormal CNV results. Other structures, especially the heart, gastrointestinal and urinary system, should be carefully examined when NVFGB is suspected.

Prenatal Ultrasound Suspicion of Cystic Fibrosis in a Multiethnic Population: Is Extensive CFTR Genotyping Needed?

In families without a Cystic Fibrosis (CF) history, fetal ultrasound bowel abnormalities can unexpectedly reveal the disease. Isolated or in association, the signs can be fetal bowel hyperechogenicity, intestinal loop dilatation and non-visualization of fetal gallbladder. In these cases, search for CF transmembrane conductance regulator (CFTR) gene mutations is part of the recommended diagnostic practices, with a search for frequent mutations according to ethnicity, and, in case of the triad of signs, with an exhaustive study of the gene. However, the molecular diagnosis remains a challenge in populations without well-known frequent pathogenic variants. We present a multiethnic cohort of 108 pregnancies with fetal bowel abnormalities in which the parents benefited from an exhaustive study of the CFTR gene. We describe the new homozygous p.Cys1410* mutation in a fetus of African origin. We did not observe the most frequent p.Phe508del mutation in our cohort but evidenced variants undetected by our frequent mutations kit. Thanks to the progress of sequencing techniques and despite the difficulties of interpretation occasionally encountered, we discuss the need to carry out a comprehensive CFTR study in all patients in case of fetal bowel abnormalities.

Practical approach to imaging diagnosis of biliary atresia, Part 1: prenatal ultrasound and magnetic resonance imaging, and postnatal ultrasound

We present a practical approach to imaging in suspected biliary atresia, an inflammatory cholangiopathy of infancy resulting in progressive fibrosis and obliteration of extrahepatic and intrahepatic bile ducts. Left untreated or with failure of the Kasai procedure, biliary atresia progresses towards biliary cirrhosis, end-stage liver failure and death by age 3. Differentiation of biliary atresia from other nonsurgical causes of neonatal cholestasis is challenging because there is no single method for diagnosing biliary atresia, and clinical, laboratory and imaging features of this disease overlap with those of other causes of neonatal cholestasis. Concerning imaging, our systematic literature review shows that ultrasonography is the main tool for pre- and neonatal diagnosis. Key prenatal features, when present, are non-visualisation of the gallbladder, cyst in the liver hilum, heterotaxy syndrome and irregular gallbladder walls. Postnatal imaging features have a very high specificity when present, but a variable sensitivity. Triangular cord sign and abnormal gallbladder have the highest sensitivity and specificity. The presence of macro- or microcyst or polysplenia syndrome is highly specific but less sensitive. The diameter of the hepatic artery and hepatic subcapsular flow are less reliable. When present in the context of acholic stools, dilated intrahepatic bile ducts rule out biliary atresia. Importantly, a normal US exam does not rule out biliary atresia. Signs of chronic hepatopathy and portal hypertension (portosystemic derivations such as patent ductus venosus, recanalised umbilical vein, splenomegaly and ascites) should be actively identified for - but are not specific for - biliary atresia.

Utility of Magnetic Resonance Imaging in Diagnosis of Prenatal Non-Visualization of the Fetal Gallbladder: A Case-Series Study

BACKGROUND This study aimed to assess the utility of magnetic resonance imaging (MRI) in the diagnosis of prenatal non-visualization of the fetal gallbladder (PNVGB). MATERIAL AND METHODS The clinical data of 32 pregnant women with PNVGB who underwent MRI examination during the second and third trimester of pregnancy were collected and their outcomes were analyzed. RESULTS MRI showed that 26 patients (81.3%) had isolated PNVGB and 6 (18.8%) had additional malformations. In 26 patients with isolated PNVGB, 7 were found in the gallbladder on MRI and 4 were found on subsequent ultrasonography. One patient had termination of pregnancy (TOP) and 1 patient was lost to follow-up; the remaining 24 patients were known to deliver a healthy child. Among the 6 patients with additional malformations, 3 terminated their pregnancies due to combined severe abnormalities: 1 patient with horseshoe kidney and 1 with fetal echogenic bowel both had a healthy child, while 1 with fetal growth restriction (FGR) delivered a child who walked on tiptoe. CONCLUSIONS MRI contributes to identifying PNVGB detected or suspected by ultrasonography.

Prenatal ultrasound diagnosis of duplication gallbladder: a multicenter study

BACKGROUND

Gallbladder duplication is a rare anatomic anomaly characterized by the presence of an accessory gallbladder.

OBJECTIVE

To appraise the prevalence and significance of prenatal diagnosis of duplication of gallbladder in a multicenter study.

METHODS

This was a multicenter case series with literature review. Clinical records of all consecutive pregnant women with a prenatal diagnosis of duplication of gallbladder, who were referred to our Centers were included in this study. The diagnosis of duplication of gallbladder was based on the evidence of double gallbladder in the standard abdominal circumference plane using grey scale. Postnatal magnetic resonance cholangiopancreatography (MRCP) 3D and postnatal neonatal abdominal ultrasound scan were offered soon after birth to confirm the diagnosis of double gallbladder. The systematic review was conducted using electronic databases from inception of each database through December 2019.

RESULTS

Five studies, including a total of seven cases, were identified as relevant and included in the systematic review. Gestational age at diagnosis ranged from 20 to 32 weeks of gestation. Associated findings were reported in only one case, where the fetus presented with a left-sided gallbladder, and bilateral renal agenesis with Potter sequence. None of the included cases reported abnormal karyotype. Our cases series included nine cases (0.03%) of double gallbladder with postnatal confirmation, with an overall incidence of this anomaly of 0.03%.Associated findings were reported in only two cases, one with IUGR and omphalocele, that opted for I-TOP, and one with single umbilical artery. Except for the I-TOP, neonatal outcome was favorable in all cases.

CONCLUSIONS

Duplication of the gallbladder is a very rare malformation with only seven cases reported in the literature diagnosed prenatally. This anomaly is not associated with abnormal karyotype, and the neonatal outcome is favorable if there are no other associated abnormalities.