Outcome and etiologies of fetal megacystis according to the gestational age at diagnosis

Antenatal Determinants of Postnatal Renal Function in Fetal Megacystis: A Systematic Review

Introduction: To evaluate the clinical usefulness of demographic data, fetal imaging findings and urinary analytes were used for predicting poor postnatal renal function in children with congenital megacystis. Materials and methods: A systematic review was conducted in MEDLINE's electronic database from inception to December 2023 using various combinations of keywords such as "luto" [All Fields] OR "lower urinary tract obstruction" [All Fields] OR "urethral valves" [All Fields] OR "megacystis" [All Fields] OR "urethral atresia" [All Fields] OR "megalourethra" [All Fields] AND "prenatal ultrasound" [All Fields] OR "maternal ultrasound" [All Fields] OR "ob-stetric ultrasound" [All Fields] OR "anhydramnios" [All Fields] OR "oligohydramnios" [All Fields] OR "renal echogenicity" [All Fields] OR "biomarkers" [All Fields] OR "fetal urine" [All Fields] OR "amniotic fluid" [All Fields] OR "beta2 microglobulin" [All Fields] OR "osmolarity" [All Fields] OR "proteome" [All Fields] AND "outcomes" [All Fields] OR "prognosis" [All Fields] OR "staging" [All Fields] OR "prognostic factors" [All Fields] OR "predictors" [All Fields] OR "renal function" [All Fields] OR "kidney function" [All Fields] OR "renal failure" [All Fields]. Two reviewers independently selected the articles in which the accuracy of prenatal imaging findings and fetal urinary analytes were evaluated to predict postnatal renal function. Results: Out of the 727 articles analyzed, 20 met the selection criteria, including 1049 fetuses. Regarding fetal imaging findings, the predictive value of the amniotic fluid was investigated by 15 articles, the renal appearance by 11, bladder findings by 4, and ureteral dilatation by 2. The postnatal renal function showed a statistically significant relationship with the occurrence of oligo- or anhydramnion in four studies, with an abnormal echogenic/cystic renal cortical appearance in three studies. Single articles proved the statistical prognostic value of the amniotic fluid index, the renal parenchymal area, the apparent diffusion coefficient (ADC) measured on fetal diffusion-weighted MRI, and the lower urinary tract obstruction (LUTO) stage (based on bladder volume at referral and gestational age at the appearance of oligo- or anhydramnios). Regarding the predictive value of fetal urinary analytes, sodium and β2-microglobulin were the two most common urinary analytes investigated (n = 10 articles), followed by calcium (n = 6), chloride (n = 5), urinary osmolarity (n = 4), and total protein (n = 3). Phosphorus, glucose, creatinine, and urea were analyzed by two articles, and ammonium, potassium, N-Acetyl-l3-D-glucosaminidase, and microalbumin were investigated by one article. The majority of the studies (n = 8) failed to prove the prognostic value of fetal urinary analytes. However, two studies showed that a favorable urinary biochemistry profile (made up of sodium < 100 mg/dL; calcium < 8 mg/dL; osmolality < 200 mOsm/L; β2-microglobulin < 4 mg/L; total protein < 20 mg/dL) could predict good postnatal renal outcomes with statistical significance and urinary levels of β2-microglobulin were significantly higher in fetuses that developed an impaired renal function in childhood (10.9 ± 5.0 mg/L vs. 1.3 ± 0.2 mg/L, p-value < 0.05). Conclusions: Several demographic data, fetal imaging parameters, and urinary analytes have been shown to play a role in reliably triaging fetuses with megacystis for the risk of adverse postnatal renal outcomes. We believe that this systematic review can help clinicians for counseling parents on the prognoses of their infants and identifying the selected cases eligible for antenatal intervention.

Single-center outcome analysis of 46 fetuses with megacystis after intrauterine vesico-amniotic shunting with the Somatex®intrauterine shunt

OBJECTIVES

To assess the spectrum of underlying pathologies, the intrauterine course and postnatal outcome of 46 fetuses with megacystis that underwent intrauterine vesico-amniotic shunting (VAS) with the Somatex® shunt in a single center.

METHODS

Retrospective analysis of 46 fetuses with megacystis that underwent VAS either up to 14 + 0 weeks (early VAS), between 14 + 1 and 17 + 0 weeks (intermediate VAS) or after 17 + 0 weeks of gestation (late VAS) in a single tertiary referral center. Intrauterine course, underlying pathology and postnatal outcome were assessed and correlated with the underlying pathology and gestational age at first VAS.

RESULTS

46 fetuses underwent VAS, 41 (89%) were male and 5 (11%) were female. 28 (61%) fetuses had isolated and 18 (39%) had complex megacystis with either aneuploidy (n = 1), anorectal malformations (n = 6), cloacal malformations (n = 3), congenital anomalies overlapping with VACTER association (n = 6) or Megacystis-Microcolon Intestinal-Hypoperistalsis Syndrome (MMIHS) (n = 2). The sonographic 'keyhole sign' significantly predicted isolated megacystis (p < 0.001). 7 pregnancies were terminated, 4 babies died in the neonatal period, 1 baby died at the age of 2.5 months and 34 (74%) infants survived until last follow-up. After exclusion of the terminated pregnancies, intention-to-treat survival rate was 87%. Mean follow-up period was 24 months (range 1-72). The underlying pathology was highly variable and included posterior urethral valve (46%), hypoplastic or atretic urethra (35%), MMIHS or prune belly syndrome (10%) and primary vesico-ureteral reflux (2%). In 7% no pathology could be detected postnatally. No sonographic marker was identified to predict the underlying pathology prenatally. 14 fetuses underwent early, 24 intermediate and 8 late VAS. In the early VAS subgroup, amnion infusion prior to VAS was significantly less often necessary (7%), shunt complications were significantly less common (29%) and immediate kidney replacement therapy postnatally became less often necessary (0%). In contrast, preterm delivery ≤ 32 + 0 weeks was more common (30%) and survival rate was lower (70%) after early VAS compared to intermediate or late VAS. Overall, 90% of liveborn babies had sufficient kidney function without need for kidney replacement therapy until last follow-up, and 95% had sufficient pulmonary function without need for mechanical respiratory support. 18% of babies with complex megacystis suffered from additional health restrictions due to their major concomitant malformations.

CONCLUSIONS

Our data suggest that VAS is feasible from the first trimester onward. Early intervention has the potential to preserve neonatal kidney function in the majority of cases and enables neonatal survival in up to 87% of cases. Despite successful fetal intervention, parents should be aware of the potential of mid- or long-term kidney failure and of additional health impairments due to concomitant extra-renal anomalies that cannot be excluded at time of intervention.

Fetal Megacystis in the first trimester: Comparing management and outcomes between longitudinal bladder length groups

Fetal megacystis is a sonographic sign, defined in first trimester as a longitudinal bladder length (LBD)>7 mm. Different causes may be associated with megacystis and outcomes vary with many factors. There are no international guidelines on how to manage megacystis cases, and invasive testing is controversial when no other abnormalities are found. The main objective of this study is to compare etiologies, management and outcomes of fetuses with first trimester megacystis, specifically between groups of LBD≤15 mm and >15 mm. This is a retrospective cohort study of megacystis cases managed in a Prenatal Diagnosis Center, between January 2009 and September 2020. Descriptive and bivariate analysis were performed. We studied 43 fetuses: 67.4% with LBD≤15 mm and 32.6% with LBD>15 mm. We found an association between LBD and isolated Low Urinary Tract Obstruction (LUTO) (3.4% vs 64.3%; p<0.001) and with isolated megacystis (44.8% vs 0.0%; p = 0.001). No differences were seen regarding the presence of aneuploidies (31.0% vs 14.3%; p = 0.213). Invasive testing was performed in 93.0% of cases. Overall, we report 41.9% of live births, 39.5% of pregnancy termination and 18.6% of intrauterine fetal demise. We found a higher rate of live births in fetuses with LBD≤15 mm (55.2% vs 14.3%; p = 0.011). For a mean follow-up time of 20.6 months, we report one neonatal death and one case of renal insufficiency. In conclusion, isolated LUTO is more frequent if LBD>15 mm whereas isolated megacystis is more frequently found if LBD≤15 mm. If LBD≤15 mm, live birth rates and long-term outcomes seem to be enhanced.

Vesicoamniotic Shunting before 17 + 0 Weeks in Fetuses with Lower Urinary Tract Obstruction (LUTO): Comparison of Somatex vs. Harrison Shunt Systems

(1) Background: The aim of this study was to compare perinatal outcomes and complication rates of vesicoamniotic shunting (VAS) before 17 + 0 weeks in isolated LUTO (lower urinary tract obstruction) with the Somatex® intrauterine shunt vs. the Harrison fetal bladder shunt. (2) Methods: This is a retrospective cohort study in two tertiary fetal medicine centers. From 2004−2014, the Harrison fetal bladder shunt was used, and from late 2014−2017, the Somatex shunt. Obstetrics and pediatric charts were reviewed for complications, course of pregnancy, perinatal outcome, and postnatal renal function. (3) Results: Twenty-four fetuses underwent VAS with a Harrison (H) shunt and 33 fetuses with a Somatex (S) shunt. Live birth rates and survival to last follow-up were significantly higher in the Somatex group, at 84.8% and 81.8%, respectively, vs. 50% and 33.3% in the Harrison group (p = 0.007 and p < 0.001). The dislocation rate in the Somatex group (36.4%) was significantly lower than in the Harrison group (87.5%) (p < 0.001). The median time to dislocation was significantly different, at 20.6 days (H) vs. 73.9 days (S) (p = 0.002), as was gestational age at dislocation (17 (H) vs. 25 (S) weeks, p < 0.001). Renal function was normal in early childhood in 51% (S) vs. 29% (H) (p = 0.11). (4) Conclusions: VAS before 17 + 0 weeks gestational age with a Somatex shunt improves perinatal survival significantly and might even have a positive effect on renal function, probably due to the lower dislocation rates. A normal amount of amniotic fluid in the third trimester was the best predictor of normal renal function in early childhood.

Megacystis in the first trimester of pregnancy: Prognostic factors and perinatal outcomes

OBJECTIVE

To determine whether bladder size is associated with an unfavorable neonatal outcome, in the case of first-trimester megacystis.

MATERIALS AND METHODS

This was a retrospective observational study between 2009 and 2019 in two prenatal diagnosis centers. The inclusion criterion was an enlarged bladder (> 7 mm) diagnosed at the first ultrasound exam between 11 and 13+6 weeks of gestation. The main study endpoint was neonatal outcome based on bladder size. An adverse outcome was defined by the completion of a medical termination of pregnancy, the occurrence of in utero fetal death, or a neonatal death. Neonatal survival was considered as a favorable outcome and was defined by a live birth, with or without normal renal function, and with a normal karyotype.

RESULTS

Among 75 cases of first-trimester megacystis referred to prenatal diagnosis centers and included, there were 63 (84%) adverse outcomes and 12 (16%) live births. Fetuses with a bladder diameter of less than 12.5 mm may have a favorable outcome, with or without urological problems, with a high sensitivity (83.3%) and specificity (87.3%), area under the ROC curve = 0.93, 95% CI (0.86-0.99), p< 0.001. Fetal autopsy was performed in 52 (82.5%) cases of adverse outcome. In the 12 cases of favorable outcome, pediatric follow-up was normal and non-pathological in 8 (66.7%).

CONCLUSION

Bladder diameter appears to be a predictive marker for neonatal outcome. Fetuses with smaller megacystis (7-10 mm) have a significantly higher chance of progressing to a favorable outcome. Urethral stenosis and atresia are the main diagnoses made when first-trimester megacystis is observed. Karyotyping is important regardless of bladder diameter.

ACR Appropriateness Criteria® Second and Third Trimester Screening for Fetal Anomaly

The Appropriateness Criteria for the imaging screening of second and third trimester fetuses for anomalies are presented for fetuses that are low risk, high risk, have had soft markers detected on ultrasound, and have had major anomalies detected on ultrasound. 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.

Perinatal outcome and prognostic factors of fetal megacystis diagnosed at 11-14 week's gestation

OBJECTIVES

To evaluate aneuploidy rate, prognostic factors, and perinatal outcomes following a diagnosis of fetal megacystis at 11-14 week's gestation.

METHODS

A retrospective study of first trimester fetal megacystis from 2010 to 2020 was performed, including ultrasound finding, perinatal outcomes, pathology reports, genetic tests, and neonatal investigations.

RESULTS

A total of 98 cases of first trimester fetal megacystis was identified with an overall aneuploidy rate of 12%. There were 54% live births and 46% fetal losses including spontaneous fetal demise and elective termination. Among the 45 fetal losses, 64% had additional structural abnormalities at index ultrasound and final diagnoses were achievable in 64% cases. Among the 53 livebirths, additional ultrasound abnormalities were detected in only 1 fetus and spontaneous resolution of megacystis was detected in 96% of cases. The two cases where fetal megacystis persisted had major postnatal diagnoses: cloacal malformation and megacystis-microcolon-intestinal hypoperistalsis syndrome, respectively. Our data showed LBD ≥ 12 mm was the best individual predictor of adverse perinatal outcome and all 11 cases of lower urinary tract obstruction (LUTO) were diagnosed in fetuses with LBD ≥ 12 mm.

CONCLUSIONS

First trimester ultrasound provides important prognostic factors and isolated megacystis <12 mm is associated with a positive outcome.

Clinical predictors of chronic kidney disease in congenital lower urinary tract obstruction

Congenital lower urinary tract obstruction is associated with oligohydramnios and significant perinatal mortality and long-term chronic kidney disease. The counseling of families facing this diagnosis, especially when prenatal intervention is proposed, is fraught with ambiguity. This review aims to equip the provider with the current evidence behind the conventional and novel biomarkers predictive of chronic kidney disease. The relevant clinical predictors are categorized by when they are identified, antenatally or postnatally, and as either anatomic or chemical. They are considered for their prognostic value and the challenges in obtaining them, specifically the risk to the fetus in the case of prenatal biomarkers. Serum creatinine in infancy is the traditional chemical biomarker of kidney function and continues to be a consistent predictor of future serum creatinine. β-2 microglobulin may provide earlier information regarding fetal glomerular and tubular function and is also predictive of long-term serum creatinine. Renal parenchymal area is an anatomic surrogate of nephron mass that is used in both prenatal and postnatal settings. Understanding the anatomic and chemical biomarkers is essential for future refinement of the staging algorithm used to distinguish which patients may benefit from early in utero intervention.

Vesicoamniotic shunting for fetal megacystis in the first trimester with a Somatex® intrauterine shunt

Purpose

The objective was to evaluate the feasibility of vesicoamniotic shunting (VAS) in the first trimester with the Somatex^® intrauterine shunt and report on complications and neonatal outcome.

Methods

Retrospective cohort study of all VAS before 14 weeks at two tertiary fetal medicine centres from 2015 to 2018 using a Somatex^® intrauterine shunt. All patients with a first trimester diagnosis of megacystis in male fetuses with a longitudinal bladder diameter of at least 15 mm were offered VAS. All patients that opted for VAS after counselling by prenatal medicine specialists, neonatologists and pediatric nephrologists were included in the study. Charts were reviewed for complications, obstetric and neonatal outcomes.

Results

Ten VAS were performed during the study period in male fetuses at a median GA of 13.3 (12.6–13.9) weeks. There were two terminations of pregnancy (TOP) due to additional malformations and one IUFD. Overall there were four shunt dislocations (40%); three of those between 25–30 weeks GA.

Seven neonates were born alive at a median GA of 35.1 weeks (31.0–38.9). There was one neonatal death due to pulmonary hypoplasia. Neonatal kidney function was normal in the six neonates surviving the neonatal period. After exclusion of TOP, perinatal survival was 75%, and 85.7% if only live-born children were considered.

Conclusion

VAS in the first trimester is feasible with the Somatex^® Intrauterine shunt with low fetal and maternal complication rates. Neonatal survival rates are high due to a reduction in pulmonary hypoplasia and the rate of renal failure at birth is very low. VAS can be safely offered from the late first trimester using the Somatex^® intrauterine shunt.

The perineal midsagittal view in male fetuses - pivotal for assessing genitourinary disorders

A wide range of genitourinary pathologies can be diagnosed in utero, from a simple vesicoureteral reflux to a more complex disorder of sexual differentiation. The prognosis and neonatal management of these conditions differ significantly. Evaluation of the fetal perineal anatomy is paramount to making the right diagnosis. The aim of this pictorial essay is to show sonographers how to acquire a perineal midsagittal view in a male fetus, and to demonstrate how this specific view allows assessment of the urethra and penis, to differentiate various genitourinary pathologies.

Fetal megacystis: a lot more than LUTO

OBJECTIVE

Fetal megacystis presents a challenge in terms of counseling and management because of its varied etiology and evolution. The aim of this study was to present a comprehensive overview of the underlying etiologies and structural anomalies associated with fetal megacystis.

METHODS

This was a retrospective multicenter study of cases referred to the fetal medicine unit of one of the eight academic hospitals in The Netherlands with a diagnosis of fetal megacystis. For each case, data on and measurements of fetal urinary tract and associated structural anomalies were collected. All available postmortem examinations and postnatal investigations were reviewed in order to establish the final diagnosis. In the first trimester, fetal megacystis was defined as longitudinal bladder diameter (LBD) ≥ 7 mm, and in the second and third trimesters as an enlarged bladder failing to empty during an extended ultrasound examination lasting at least 40 min.

RESULTS

Of the 541 pregnancies with fetal megacystis, it was isolated (or solely accompanied by other signs of lower urinary tract obstruction (LUTO)) in 360 (67%) cases and associated with other abnormal ultrasound findings in 181 (33%) cases. The most common associated ultrasound anomaly was an increased nuchal translucency thickness (22%), followed by single umbilical artery (10%) and cardiac defect (10%). A final diagnosis was established in 418 cases, including 222 (53%) cases with isolated LUTO and 60 (14%) infants with normal micturition or minor isolated urological anomalies. In the remaining 136 (33%) cases, concomitant developmental or chromosomal abnormality or genetic syndrome was diagnosed. Overall, 40 chromosomal abnormalities were diagnosed, including trisomy 18 (n = 24), trisomy 21 (n = 5), Turner syndrome (n = 5), trisomy 13 (n = 3) and 22q11 deletion (n = 3). Thirty-two cases presented with anorectal malformations involving the anus, rectum and urogenital tract. In cases with confirmed urethral and anal atresia, megacystis occurred early in pregnancy and the bladder appeared severely distended (the LBD (in mm) was equal to or greater than twice the gestational age (in weeks)). Fetal macrosomia was detected in six cases and an overgrowth syndrome was detected in four cases, comprising two infants with Beckwith-Wiedemann syndrome and two with Sotos syndrome. Megacystis-microcolon-intestinal hypoperistalsis syndrome was diagnosed in five (1%) cases and prenatally suspected only in one case.

CONCLUSIONS

Although the main cause of fetal megacystis is LUTO, an enlarged fetal bladder can also be present as a concomitant finding of miscellaneous genetic syndromes, developmental disturbances and chromosomal abnormalities. We provide an overview of the structural anomalies and congenital disorders associated with fetal megacystis and propose a practical guide for the differential diagnosis of genetic syndromes and chromosomal and developmental abnormalities in pregnancies presenting with fetal megacystis, focusing on the morphological examination of the fetus. © 2018 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.

Outcomes in fetuses diagnosed with megacystis: Systematic review and meta-analysis

OBJECTIVE

To explore the outcomes and prognostic factors associated with fetal megacystis (enlarged bladder).

STUDY DESIGN

The MEDLINE and EMBASE databases were searched for studies reporting on outcomes of fetal megacystis. The outcomes observed were chromosomal abnormalities, associated structural anomalies, spontaneous resolution, and survival rates. We also evaluated the potential role of fetal gender, oligohydramnios, gestational age at diagnosis, and intrauterine intervention as prenatal prognostic factors.

RESULTS

The search identified 558 articles in total, and 13 studies (1675 fetuses) were included in this systematic review. The overall incidences of chromosomal abnormalities and associated structural anomalies in fetal megacystis were 10% and 24%, respectively. Spontaneous resolution of megacystis occurred in 32% of fetuses, and 44% of fetuses were born alive and survived until the follow-up. The odds ratio of survival with oligohydramnios was 0.14, and the mean difference in gestational age at diagnosis between survival and non-survival was 3.43 weeks. No significant difference in survival rate was observed between the genders, and an intrauterine intervention did not significantly improve the prognosis.

CONCLUSIONS

A considerable proportion of fetuses with megacystis are born with a good prognosis. Oligohydramnios and lower gestational age at diagnosis are associated with worse outcomes.

Prenatal diagnosis of LUTO: improving diagnostic accuracy

OBJECTIVE

To propose a clinical score for the optimal antenatal diagnosis of fetal lower urinary tract obstruction (LUTO) in the second and third trimesters of pregnancy, as an alternative to the commonly used ultrasound triad of megacystis, keyhole sign and hydronephrosis.

METHODS

This was a national retrospective study carried out at the eight tertiary fetal medicine units (FMUs) in The Netherlands. Only cases referred for megacystis from the second trimester onwards and with a clear postnatal diagnosis were included in the study. At referral, data were collected on amniotic fluid volume, renal cortical appearance, bladder volume, hydronephrosis, fetal ascites, ureteral size, keyhole sign, fetal sex and gestational age. Multivariate analysis was performed, starting by including all antenatal variables, and then excluding the weakest predictors using the backward stepwise strategy.

RESULTS

Over a 7-year period, 312 fetuses with a diagnosis of megacystis were referred to the eight Dutch tertiary FMUs. A final diagnosis was achieved in 143 cases, including 124 of LUTO and 19 reclassified after birth as non-obstructive megacystis. The optimal bladder volume cut-off for prediction of LUTO was 35 cm³ (area under the curve (AUC) = 0.7, P = 0.03). The clinical score formulated on the basis of the multivariate analysis included fetal sex, degree of bladder distension, ureteral size, oligo- or anhydramnios and gestational age at referral. The combination of these five variables demonstrated good accuracy in discriminating LUTO from non-obstructive megacystis (AUC = 0.84, P < 0.001), compared with the poor performance of the ultrasound triad (AUC = 0.63, P = 0.07).

CONCLUSIONS

We propose a clinical score that combines five antenatal variables for the prospective diagnosis of congenital LUTO. This score showed good discriminative capacity in predicting LUTO, and better diagnostic accuracy compared with that of the classic ultrasound triad. Future studies to validate these results should be carried out in order to refine antenatal management of LUTO and prevent inappropriate fetal interventions. © 2017 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.

Early fetal megacystis: Is it possible to predict the prognosis in the first trimester?

OBJECTIVE

To evaluate the best management of fetal megacystis diagnosed in the first trimester and define the prognosis and the most appropriate follow-up as early as possible.

METHODS

This is a retrospective study of first-trimester fetal megacystis diagnosed in pregnant women who performed a combined screening for fetal aneuploidy. Megacystis was defined as a longitudinal bladder diameter (LBD) greater than 7 mm. All fetuses were divided into two groups according to the LBD: Group A with LBD > 15 mm and Group B with LBD < 15 mm. The fetal karyotype and associated anomalies were evaluated. Ultrasound monitoring was performed every 2 weeks (a second ultrasound scan after 2 weeks from diagnosis and a third ultrasound scan 2 weeks after the second one).

RESULTS

Twenty-six cases were identified between 2011 and 2016; three cases of aneuploidy were excluded from the study. Of the remaining 23 cases, 11 were included in Group A and 12 in Group B. All Group A fetuses had an adverse outcome. In Group B: five (41.7%) cases had an adverse outcome and seven (58.3%) had a spontaneous resolution of megacystis. The ultrasound findings of both the ultrasound scans, the second and the third, were 100% concordant.

CONCLUSION

An ultrasound scan performed 2 weeks after the megacystis diagnosis can predict the outcome in fetuses with an LBD < 15 mm as early as the end of the first trimester. The outcome of euploid fetuses with an LBD < 15 mm was favorable in 58.3% of the cases.

Perinatal Outcomes of Fetal Lower Urinary Tract Obstruction After Vesicoamniotic Shunting Using a Double-Basket Catheter

OBJECTIVES

To evaluate the perinatal survival and renal function of fetuses with lower urinary tract obstruction (LUTO) who underwent vesicoamniotic shunting using a double-basket catheter METHODS: We retrospectively reviewed 32 fetuses with LUTO who underwent vesicoamniotic shunting using a double-basket catheter between 1998 and 2013.

RESULTS

Among the 32 fetuses examined, 5 died because of termination of pregnancy, and 2 died in utero. The median gestational age at diagnosis was 15.5 (range, 10.0-27.3) weeks, and that at initial shunting was 17.1 (range, 12.3-32.2) weeks. Shunt dislocation or occlusion occurred in 18 of 42 procedures (42.8%). The median gestational age at delivery for the 25 live births was 35.5 (range, 28-40) weeks. Postnatal diagnosis revealed posterior urethral valves in 15 fetuses, a cloacal anomaly in 7, and urethral stenosis in 3. Three neonatal deaths occurred, resulting in an overall perinatal survival rate of 68.8% (22 of 32). The rates of normal renal function were 40.6% (13 of 32) at 28 days and 40% (10 of 25) at 2 years after birth. The absence of oligohydramnios after shunting was the only prognostic factor for normal renal function at 2 years (P < .05).

CONCLUSIONS

Vesicoamniotic shunting may be helpful for fetuses with LUTO.

Comparison of biochemical analysis of fetal serum and fetal urine in the prediction of postnatal renal outcome in lower urinary tract obstruction

OBJECTIVES

To compare the prognostic value of fetal serum biochemistry and fetal urine biochemistry in predicting renal outcome in lower urinary tract obstruction (LUTO).

METHODS

We retrospectively studied renal outcome following a prenatal diagnosis of LUTO in cases for which both fetal blood and fetal urine were sampled. We classified the renal outcome as either "favorable," when postnatal renal function was normal, or "adverse," in the case of postnatal chronic renal failure or when renal histological lesions were present at autopsy in the case of termination of pregnancy. A prognostic model was constructed for urine and serum separately. β2-Microglobulin was the only remaining independent predictor in fetal urine. β2-Microglobulin in serum and urine were compared by using receiver operating characteristic curves.

RESULTS

In the 50 cases included, the rate of adverse outcome was 34 of 50(68%): autopsy confirmed severity of renal disease in all 27 cases who underwent termination of pregnancy, and among the 23 live born children, 7 developed renal failure. Fetal serum and urine markers were all significantly associated with renal outcome (P < .01). The receiver operating characteristic curves for fetal serum and fetal urinary β2-microglobulin were similar (area under the curve = 0.908 versus 0.909, P = .96).

CONCLUSION

Fetal serum biochemistry and fetal urine biochemistry are of similar prognostic value in predicting postnatal renal outcome in fetuses with LUTO.

Diagnosis of fetal megacystis with chromosomal abnormality by 2D prenatal ultrasound: A case report

RATIONALE

The pathogenesis of fetal megacystis is divided into obstructive and nonobstructive. Megacystis combined with chromosomal abnormalities is rare and most of the cases are nonobstructive.

PATIENT CONCERNS

The fetus showed posterior urethral obstructive megacystis with features of bladder enlargement, "keyhole" feature, and thick bladder wall.

DIAGNOSES

Here, we present a case of fetal megacystis diagnosed by ultrasound at pregnancy week 15+2 and with multisystem abnormalities.

OUTCOMES

Moreover, the fetus showed edema, umbilical cord cyst, cardiac dysplasia, hook-shaped hand, and strephenopodia. These abnormalities strongly suggested chromosomal abnormalities. The fetus was diagnosed with trisomy 18 by amniocentesis. Posterior urethral obstructive megacystis was confirmed by pathology.

LESSONS

In conclusion, this case suggests that in the presence of fetal megacystis and multisystem abnormalities, causes should be investigated and the possibility of chromosomal abnormalities should be considered in the presence of multisystem developmental abnormalities.

Fetal megacystis: prediction of spontaneous resolution and outcome

OBJECTIVES

To investigate the natural history of fetal megacystis from diagnosis in utero to postnatal outcome, and to identify prognostic indicators of spontaneous resolution and postnatal outcome after resolution.

METHODS

This was a national retrospective cohort study. Fetal megacystis was defined in the first trimester as a longitudinal bladder diameter (LBD) ≥ 7 mm, and in the second and third trimesters as an enlarged bladder failing to empty during the entire extended ultrasound examination. LBD and gestational age (GA) at resolution were investigated with respect to likelihood of resolution and postnatal outcome, respectively. Sensitivity, specificity and area under the receiver-operating characteristics curve (AUC) were calculated.

RESULTS

In total, 284 cases of fetal megacystis (93 early megacystis, identified before the 18^th week, and 191 late megacystis, identified at or after the 18^th week) were available for analysis. Spontaneous resolution occurred before birth in 58 (20%) cases. In cases with early megacystis, LBD was predictive of the likelihood of spontaneous resolution (sensitivity, 80%; specificity, 79%; AUC, 0.84), and, in the whole population, GA at regression was predictive of postnatal outcome, with an optimal cut-off at 23 weeks (sensitivity, 100%; specificity, 82%; AUC, 0.91). In the group with early megacystis, the outcome was invariably good when resolution occurred before the 23^rd week of gestation, whereas urological sequelae requiring postnatal surgery were diagnosed in 3/8 (38%) cases with resolution after 23 weeks. In the group with late megacystis, spontaneous resolution was associated with urological complications after birth, ranging from mild postnatal hydronephrosis in infants with resolution before 23 weeks, to more severe urological anomalies requiring postnatal surgery in those with resolution later in pregnancy. This supports the hypothesis that an early resolution of megacystis is often related to a paraphysiological bladder enlargement that resolves early in pregnancy without consequences, while antenatal resolution occurring later in pregnancy (after the 23^rd week of gestation) should suggest a pathological condition with urological sequelae.

CONCLUSIONS

In fetal megacystis, LBD and GA at regression can be used as predictors of resolution and outcome, respectively. These parameters could help in fine-tuning the prognosis and optimizing the frequency of follow-up scans. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Prenatal detection of megacystis: not always an adverse prognostic factor. Experience in 25 consecutive cases in a tertiary referral center, with complete neonatal outcome and follow-up

INTRODUCTION

Megacystis is a condition of abnormal enlarged fetal bladder for gestational age, which is usually associated with urological malformations that may constitute a life-threatening condition for the baby.

OBJECTIVE

The purpose of this study was to assess the prognostic and etiological criteria of fetal megacystis and to describe the neonatal outcome in a large series collected in a single tertiary center.

STUDY DESIGN

A retrospective observational study was conducted between 2008 and 2012. We reviewed all consecutive cases of fetal megacystis diagnosed during routine ultrasound (US) screening. The following data were collected and analyzed: maternal age, gestational age at diagnosis, prenatal ultrasonographic details of the urinary system, extra-urinary ultrasonographic anomalies, fetal karyotype, pregnancy outcome, postnatal diagnosis, and medical/surgical follow-up.

RESULTS

Of the 25 fetuses included in this study, 76% were males. The mean gestational age (GA) at diagnosis was 23.1 ± 7.5 weeks (range 12-34), among them only four (16%) were diagnosed during the first trimester. Associated urological malformations were detected in 92% (n = 23) of the cases, while other malformations were detected in 36% (n = 9). Oligohydramnios or anyhydramnios were observed in 52% (n = 13) of the cases. Twelve (48%) fetuses were considered as having poor prognosis for renal function. Vesicocentesis with or without vesico-amniotic infusion were performed in 28% (n = 7) of the cases. Pregnancy outcome was surprisingly good, with only one case of prenatal death and survival rate of 96% (n = 24) of liveborn babies. Posterior urethral valve (PUV) (n = 9, 36%) was the most common etiology of the fetal megacystis, followed by persistent urogenital sinus (n = 2, 8%), Prune belly syndrome (n = 2, 8%) and bilateral vescico-ureteral reflux (VUR) (n = 2, 8%). Surgical or endoscopic procedures were performed in 75% (n = 18) of the cases. Six (24%) newborns presented with moderate/severe respiratory distress that requested invasive assisted ventilation. Three cases (n = 3, 12%) of perinatal death were observed due to severe impaired renal function. After a median follow-up of 29 months renal function was good in 79% (n = 19) of the cases.

CONCLUSIONS

Fetal megacystis may underline a wide range of associated pathologies with the highest prevalence of urinary malformation. Optimal counseling of the involved parents requires a multidisciplinary approach to allow the best management during the pregnancy and the perinatal period. Despite the high risk of renal failure, lung hypoplasia, and severe associated anomalies, the outcome of fetuses with megacystis could be improved thanks to an appropriate perinatal diagnosis and neonatal management.

Fetal megacystis: A systematic review

Fetal megacystis is variably defined and understood. The literature on fetal megacystis was systematically reviewed, focusing on prenatal diagnosis, associations and outcomes. This yielded a total of 18 primary references and eight secondary references. Fetal megacystis has an estimated first-trimester prevalence of between 1:330 and 1:1670, with a male to female ratio of 8:1. In the first trimester, megacystis is most commonly defined as a longitudinal bladder dimension of ≥7 mm. Later in pregnancy, a sagittal dimension (in mm) greater than gestational age (in weeks) + 12 is often accepted. Megacystis can be associated with a thickened bladder wall, which has been objectively defined as >3 mm. Oligohydramnios is present in approximately half of all cases. The most common underlying diagnosis is posterior urethral valves (57%), followed by urethral atresia/stenosis (7%), prune belly syndrome (4%), megacystis-microcolon-intestinal-hypoperistalsis syndrome (MMIHS) (1%), and cloacal anomalies (0.7%). Karyotype anomalies are found in 15%, and include trisomy 18, trisomy 13 and trisomy 21. Ultrasound imaging alone is often insufficient to enable a definitive diagnosis, although it may indicate that a specific diagnosis is more likely. Overall, about 50% of reported fetuses with megacystis are terminated, but this proportion varies considerably between countries and over time. Prognostic stratification is evolving, with the most important factors being oligohydramnios, gestational age at diagnosis, degree of bladder enlargement, renal hyperechogenicity, karyotype, and sex.

CONCLUSIONS

This review demonstrated some consensus on the ultrasound criteria for defining fetal megacystis, and illustrated the spectrum of pathologies and their relative frequencies that can cause this condition. It also underlined important associated karyotype anomalies. To progress understanding of the natural history of enlarged fetal bladders, more accurate diagnostics are required, and risk stratification needs to be refined to facilitate prenatal counseling.

Types and Outcome of Fetal Urinary Anomalies in Low Resource Setting Countries: A Retrospective Study

BACKGROUND

Congenital anomalies of the kidney and urinary tract in the developing countries have a poor prognosis due to limited experience in antenatal and postnatal management.

PATIENTS AND METHODS

A 3-year retrospective study was carried out from January 2011 to December 2013. The following data were collected and analyzed: maternal age, gravidity, parity, gestational age at diagnosis, and ultrasonography findings. Final diagnosis after birth, the performed surgeries, follow-up data, as well as survival at one year were also analyzed.

RESULTS

The mean age of the included patients was 28 years (range 20-35 years). The mean parity was 1.7 (range 0-4). The mean gestational age at diagnosis was 26 weeks (range 15-36 weeks). Consanguinity was reported in 10 cases (24.4 %). There were 25 males and 16 females. Bilateral renal agenesis was the commonest type (19.5 %). The anomalies of kidneys and urinary tract in our cases were associated with other anomalies in 8 cases (19.5 %). Oligohydramnios was detected in bilateral renal agenesis and posterior urethral valve. Surgical interference during the first 6 months was performed in 6 cases; pyeloplasty for unilateral or bilateral hydronephrosis was performed in 5 cases; and excision of solitary renal cyst performed in one case. By the end of the first year, two of the three cases with chronic renal disease, who were under peritoneal dialysis, died, and three cases who had undergone pyeloplasty were lost to follow-up.

CONCLUSION

Among the 41 cases with antenatally diagnosed renal and urinary malformations; bilateral renal agenesis was the commonest anomaly (19.5 %). There were high rates of induction of abortion, IUFD, and neonatal deaths. The poor outcome may be due to lack of experience in performing invasive therapeutic fetal procedures.

Fetal urine biochemistry at 13-23 weeks of gestation in lower urinary tract obstruction: criteria for in-utero treatment

OBJECTIVES

To assess the value of fetal urine biochemistry before 23 weeks of gestation in cases of lower urinary tract obstruction (LUTO) to refine prognosis and to select potential candidates for in-utero intervention.

METHODS

This was a retrospective study including 72 cases of LUTO with fetal urine sampled before 23 weeks and assayed for total protein, β-2-microglobulin, sodium, chloride, calcium, phosphorus, glucose and gamma-glutamyl transpeptidase (GGTP). Two groups were defined according to renal outcome: 1) bilateral renal dysplasia on histological examination or renal failure at birth; 2) normal postnatal renal function or histologically normal appearance of the kidneys. Correlations between fetal urinary biochemical markers and postnatal renal function were studied.

RESULTS

LUTO was isolated in 56/72 (77.8%) cases and was associated with other malformations in 16/72 (22.2%) cases. High GGTP levels (236 IU/L vs 5 IU/L; P < 0.0001) were observed in fetal urine in the five cases of urodigestive fistula. A significant difference between outcome groups was observed for β-2-microglobulin (P = 0.0017), sodium (P = 0.0008), chloride (P = 0.0028) and calcium (P = 0.0092) but not for protein, glucose or phosphorus. Sensitivity and specificity in defining a poor renal prognosis were 80.6% and 89% for β-2-microglobulin, 61.3% and 100% for sodium and 64.5% and 100% for calcium, respectively.

CONCLUSIONS

Fetal urinalysis before 23 weeks of gestation allowed distinction between three groups: 1) fetuses with normal urine biochemistry for which fetal therapy should be discussed; 2) fetuses with abnormal urine biochemistry for which prognosis for renal outcome is poor and for which the benefit of fetal therapy is likely to be compromised; 3) fetuses with urodigestive fistula.

Lower urinary tract obstruction in the fetus and neonate

This article summarizes the most recent literature regarding congenital lower urinary tract obstruction in the fetus and newborn. Lower urinary tract obstruction is a heterogeneous group of rare diagnoses that have significant potential for in utero mortality and long-term morbidity in survivors. The diagnosis and management of the most common causes are reviewed. In addition, the current state of prenatal intervention for congenital lower urinary tract obstruction is discussed.