The PLUTO trial: a missed opportunity

Comparison of outcomes of prenatal versus postnatal presentation of posterior urethral valves: a systematic review and meta-analysis

OBJECTIVE

To determine through a comprehensive systematic review and meta-analysis the differences in the outcomes of prenatally versus postnatally diagnosed posterior urethral valves (PUV) to ascertain if prenatal detection of PUV has superior outcomes.

METHODS

We conducted a systematic review and meta-analysis in March 2022 (PROSPERO ID - CRD42021243546) and included all studies that reported outcomes of prenatally and postnatally diagnosed PUV. However, for meta-analysis, only those studies that described both groups were included. The main outcomes of interest included progression of chronic kidney disease (CKD), need for renal replacement therapy (RRT) and renal transplant, and bladder dysfunction as determined by initiation of clean intermittent catheterization (CIC). Time to event analyses were completed when possible.

RESULTS

The systematic review included 49 studies (3820 patients). The pooled effect estimates for progression to CKD (OR 0.75 [95% CI 0.43, 1.31]), need for RRT (OR 1.39 [95% CI 0.64, 2.99]) and need for renal transplant (OR 1.64 [95% CI 0.61, 4.42]) between prenatal and postnatal groups was not different. CICs rates were as high as 32% in the prenatal group and 22% in the postnatal group. Most studies had a moderate or serious risk of bias.

CONCLUSION

The existing comparative literature on prenatal versus postnatal presentation of PUV is very heterogeneous. The diagnostic and treatment protocols have not been reported in majority of the studies. The outcome variables are also reported inconsistently. Based on the current evidence, prenatal diagnosis of PUV does not appear to improve the long-term outcomes of these patients.

Pre-natal vs Post-natal Presentation of PUV: A Multi-institutional Experience

OBJECTIVE

To compare the outcomes of prenatally versus postnatally diagnosed posterior urethral valves (PUV) at two large pediatric centres in North America to ascertain if the prenatal diagnosis of PUV is associated with better outcomes.

MATERIALS AND METHODS

All patients with PUV were identified at 2 large pediatric institutions in North America between 2000-2020 (The Hospital for Sick Children [SK] and Children's Hospital of Philadelphia [CHOP]). Baseline characteristics and outcome measures were compared between those diagnosed prenatally vs. postnatally. Main outcomes of interest included progression of chronic kidney disease (CKD), the need for renal replacement therapy (RRT) and bladder function compromise as determined by need for clean intermittent catheterization (CIC). Time-to-event analyses were completed when possible.

RESULTS

During the study period, 152 patients with PUV were treated at SK (39% prenatal) and 216 patients with PUV were treated at CHOP (71% prenatal). At SK, there was no difference between prenatal and postnatal groups in the proportion of patients who required RRT, progressed to CKD stage 3 and above, or who were managed with CIC when comparing the timing of diagnosis. The time to event for RRT and CIC was significantly younger for prenatally detected PUV. At CHOP, significantly more prenatal patients required RRT, however there was no significant difference in the age this outcome was reached. The proportion of children managed with CIC was not different but the time to event was significantly earlier in the prenatal group.

CONCLUSION

This study represents the largest multi-institutional series of patients with PUV and failed to identify any difference in the outcomes of prenatal versus postnatal detection of PUV. A multidisciplinary approach with standardization of the treatment pathways will help in understanding the true impact of prenatal/ early detection on outcomes of PUV.

Professional integrity in maternal - fetal innovation and research: an essential component of perinatal medicine

OBJECTIVES

Clinical innovation and research on maternal-fetal interventions have become an essential for the development of perinatal medicine. In this paper, we present an ethical argument that the professional virtue of integrity should guide perinatal investigators.

METHODS

We present an historical account of the professional virtue of integrity and the key distinction that this account requires between intellectual integrity and moral integrity.

RESULTS

We identify implications of both intellectual and moral integrity for innovation, research, prospective oversight, the role of equipoise in randomized clinical trials, and organizational leadership to ensure that perinatal innovation and research are conducted with professional integrity.

CONCLUSIONS

Perinatal investigators and those charged with prospective oversight should be guided by the professional virtue of integrity. Leaders in perinatal medicine should create and sustain an organizational culture of professional integrity in fetal centers, where perinatal innovation and research should be conducted.

Fetal interventions for congenital renal anomalies

Congenital abnormalities of the kidney and urinary tract (CAKUT) represent 20% of prenatally diagnosed congenital abnormalities. Although the majority of these abnormalities do not require intervention either pre or postnatally, there is a subset of patients whose disease is so severe that it may warrant intervention prior to delivery to prevent morbidity and mortality. These cases consist of patients with moderate lower urinary tract obstruction (LUTO) in which vesicocentesis, shunting or cystoscopy are options and patients with early pregnancy renal anhydramnios (EPRA) in whom amnioinfusion therapy may be an option. The main causes of EPRA are congenital bilateral renal agenesis (CoBRA), cystic kidney disease (CKD) and severe LUTO. Untreated, EPRA is universally fatal secondary to anhydramnios induced pulmonary hypoplasia. The evidence regarding therapy for LUTO is limited and the stopped early PLUTO (Percutaneous Shunting in Lower Urinary Tract Obstruction) trial was unable to provide definitive answers about patient selection. Evidence for EPRA therapy is also scant. Serial amnioinfusions have shown promise in cases of EPRA due to CoBRA or renal failure and this treatment modality forms the basis of the ongoing NIH funded RAFT (Renal Anhydramnios Fetal Therapy) trial. At present, there is consensus that treatment for EPRA should only occur in the setting of a clinical trial.

The TOTAL trial dilemma: A survey among professionals on equipoise regarding fetal therapy for severe congenital diaphragmatic hernia

OBJECTIVE

Running randomized clinical trials (RCT) in fetal therapy is challenging. This is no different for fetoscopic endoluminal tracheal occlusion (FETO) for severe left-sided Congenital Diaphragmatic Hernia (CDH). We assessed the knowledge, attitude and practice (KAP) of maternal-fetal medicine specialists toward the antenatal management of CDH, and the randomized controlled clinical (RCT) "Tracheal Occlusion To Accelerate Lung growth-trial."

METHODS

A cross-sectional KAP-survey was conducted among 311 registrants of the 18th World Congress in Fetal Medicine.

RESULTS

The overall knowledge of CDH and FETO was high. Remarkably only 45% considers prenatal prediction of neonatal outcome reliable. Despite, in their clinical practice they perform severity assessment (80%) and refer families for FETO either within the context of an RCT (43%) or on patient request (32%). Seventy percent perceives not offering FETO on patient demand seems as if no treatment is provided to a fetus with predicted poor outcome. Only 20% of respondents considers denying access to FETO on patient demand not as a psychological burden.

CONCLUSION

Often the views of individual respondents contradicted with their clinical practice. It seems that, for severe CDH, clinicians face personal and practical dilemmas that undermine equipoise. To us, this indicates the tension between the clinical and scientific obligations physicians experience.

Antenatal intervention for congenital fetal lower urinary tract obstruction (LUTO): a systematic review and meta-analysis

Objective: To evaluate the effectiveness of antenatal intervention for the treatment of congenital lower urinary tract obstruction (LUTO) in improving perinatal survival and postnatal renal function.Methods: Electronic databases were searched from their inception until May 2018. Selection criteria included randomized controlled trials and nonrandomized studies including fetuses with ultrasound evidence of LUTO evaluating antenatal intervention for improving perinatal outcomes. Any type of antenatal bladder drainage technique was analyzed. The primary outcome was perinatal survival. The secondary outcome was postnatal survival with normal renal function. The summary measures were reported as summary odds ratio (OR) with 95% of confidence interval (CI).Results: Ten articles with a total of 355 fetuses were included in the meta-analysis. Inclusion criteria of the selected studies were singleton pregnancy with severe LUTO confirmed on detailed fetal ultrasound examination. Nine studies analyzed the efficacy of vesico-amniotic shunt performed in the second trimester. The overall estimate survival was higher in the vesico-amniotic shunt group compared to the conservative group (OR: 2.54, 95% CI: 1.14-5.67). 64/112 fetuses (57.1%) survived in the vesico-amniotic shunt group compared to 52/134 (38.8%) in the control group. Five studies reported on postnatal renal function between 6 months and 2 years. Rate of good postnatal renal function was higher in the vesico-amniotic shunt group compared to the conservative group (OR: 2.09, 95% CI: 0.74-5.9). Fetal cystoscopy was performed in only two included studies. Overall, 45 fetuses underwent fetal cystoscopy. The perinatal survival was higher in the cystoscopy group compared to the conservative management group (OR: 2.63, 95% CI: 1.07-6.47). Normal renal function was noted in 13/34 fetuses in the cystoscopy group versus 12/61 in the conservative management group at 6 months follow-up (OR: 1.75, 95% CI: 1.05-2.92)Conclusions: Antenatal bladder drainage appears to improve perinatal survival in cases of LUTO.

Clinical Outcome of Children With Antenatally Diagnosed Hydronephrosis

Fetal renal pelvis dilation is a common condition, which is observed in 1-4. 5% of pregnancies. In many cases, this finding resolves spontaneously. However, sometimes it may be a signal of significant urinary tract pathologies. The main abnormalities found after birth are uretero-pelvic junction stenosis, primary vesicoureteral reflux, megaureter, duplex kidneys, and posterior urethral valves, with uretero-pelvic junction stenosis and primary vesicoureteral reflux accounting for most of the cases. Diagnosis, management, and prognosis at short and longer term of these conditions will be reviewed in this article.

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.

Effectiveness of vesicoamniotic shunt in fetuses with congenital lower urinary tract obstruction: an updated systematic review and meta-analysis

OBJECTIVE

To evaluate the effect on perinatal and postnatal survival of vesicoamniotic shunt (VAS) as treatment for fetal lower urinary tract obstruction (LUTO).

METHODS

An electronic search of Ovid MEDLINE, Ovid EMBASE, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews and Scopus using relevant search terms was conducted from inception to June 2015 to identify studies comparing outcomes of VAS vs conservative management for treatment of LUTO. Cohort studies and clinical trials were considered eligible. Single-arm studies and studies that did not report survival were excluded. Sample size and language were not criteria for exclusion. Two reviewers extracted independently data in a standardized form, including study characteristics and results. Primary outcomes were perinatal and postnatal survival. Secondary outcome was postnatal renal function. Data on fetal survival were expressed as odds ratio (OR) and 95% CI.

RESULTS

Of the 423 abstracts retrieved, nine studies were eligible for inclusion. These studies included 112 fetuses treated with VAS and 134 that were managed conservatively. There was heterogeneity in study design. Although the data demonstrated a difference in effect estimates between the study arms in terms of perinatal survival (OR, 2.54 (95% CI, 1.14-5.67)), there was no difference in 6-12-month survival (OR, 1.77 (95% CI, 0.25-12.71)) or 2-year survival (OR, 1.81 (95% CI, 0.09-38.03)). In addition, there was no difference in effect on postnatal renal function between fetuses that underwent intervention and those that did not (OR, 2.09 (95% CI, 0.74-5.94)).

CONCLUSIONS

Available data seem to support an advantage for perinatal survival in fetuses treated with VAS compared with conservative management. However, 1-2-year survival and outcome of renal function after VAS procedure remain uncertain. Further studies are necessary to evaluate the effectiveness of fetal intervention for LUTO based on different severity of the disease, due to the very low quality of the studies according to GRADE guidelines. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

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.

Fetal surgery: an overview

In utero fetal surgery interventions are currently considered in selected cases of congenital diaphragmatic hernia, cystic pulmonary abnormalities, amniotic band sequence, selected congenital heart abnormalities, myelomeningocele, sacrococcygeal teratoma, obstructive uropathy, and complications of twin pregnancy. Randomized controlled trials have demonstrated an advantage for open fetal surgery of myelomeningocele and for fetoscopic selective laser coagulation of placental vessels in twin-to-twin transfusion syndrome. The evidence for other fetal surgery interventions, such as tracheal occlusion in congenital diaphragmatic hernia, excision of lung lesions, fetal balloon cardiac valvuloplasty, and vesicoamniotic shunting for obstructive uropathy, is more limited. Conditions amenable to intrauterine surgical treatment are rare; the mother may consider termination of pregnancy as an option for many of them; treatment can be lifesaving but in itself carries risks to both the infant (preterm premature rupture of the membranes, preterm delivery) and the mother. This makes conducting prospective or randomized trials difficult and explains the relative lack of good-quality evidence in this field. Moreover, there is scanty information on long-term outcomes. It is recommended that fetal surgery procedures be performed in centers with extensive facilities and expertise. The aims of this review were to describe the main fetal surgery procedures and their evidence-based results and to provide generalist obstetricians with an overview of current indications for fetal surgery.

Prenatal counselling and the role of the paediatric surgeon

With the development of prenatal ultrasound and of foetal medicine, the paediatric surgeon has extended his knowledge of the natural history of surgical malformations. He is a part of the prenatal team and parents should always be referred to him when a surgical malformation is suspected, even when termination of pregnancy is planned because of an expected poor prognosis. Direct contact between the prenatal medicine specialist and the paediatric surgeon is also highly recommended to ensure continuity in the messages delivered to the parents. Postnatal counselling does not compare with prenatal counselling, and the paediatric surgeon has learned from the obstetrician to modulate his talk by including other conditions that might affect the outcome of the foetus, especially genetically determined syndromes. When the foetal malformation is diagnosed very early, especially in the first trimester, it therefore seems important for the consultation with the paediatric surgeon to be scheduled when the complementary exams required by the anomalies diagnosed are done, in order to avoid later contradictory messages. Repeated consultations should be favoured as they allow provision of more precise information regarding changes in ultrasound and/or MRI images and so decrease parents׳ anxiety and help them to take their decision. Foetal surgery, which has reached various stages of development in different countries, requires paediatric surgeons and obstetricians to join forces to optimise procedures and evaluate their benefit/risk ratio. Since 2004, the National Rare Disease Plan in France has allowed the creation of Rare Disease Centres, which deal with congenital malformations and produce recommendations for the health care pathway of these patients by means of a multidisciplinary approach. This greatly enhances interdisciplinary communication and ensures that best care is provided to the parents-to-be and to their child.