Congenital urinary tract obstruction

Associations between PM2.5, ambient heat exposure and congenital hydronephrosis in southeastern China

Objectives

This research aims to analyze how exposure to fine particulate matter (PM2.5) and ambient heat during pregnancy increases the risk of congenital hydronephrosis (CH) in newborns.

Methods

A case-control study was conducted to investigate the relationship between exposure to PM2.5 and ambient heat during pregnancy and the occurrence of CH in newborns. The study, which was conducted from 2015 to 2020, included 409 infants with CH as the case group and 409 infants without any abnormalities as the control group. Using spatial remote sensing technology, the exposure of each pregnant mother to PM2.5 concentration was meticulously mapped. Additionally, data on the ambient temperature of exposure for each participant were also collected. A logistics regression model was used to calculate the influence of exposure to PM2.5 and ambient heat on the occurrence of CH. Stratified analysis and interaction analysis were used to study the interaction between ambient heat exposure and PM2.5 on the occurrence of CH.

Results

At the 6th week of gestation, exposure to PM2.5 may increase the risk of CH. For every 10 μg/m3 increase in PM2.5 exposure, the risk of CH increased by 2% (95%CI = 0.98, 1.05) at a p-value of >0.05, indicating that there was no significant relationship between the results. Exposure to intense heat at 6th and 7th weeks of gestation increased the risk of CH. Specifically, for every 1°C increase in heat exposure, the risk of CH in offspring increased by 21% (95%CI = 1.04, 1.41) during the 6th week and 13% during the 7th week (95%CI = 1.02, 1.24). At 5th and 6th weeks of gestation, the relative excess risk due to interaction (RERI) was greater than 0 at the 50th percentile (22.58°C), 75th percentile (27.25°C), and 90th percentile (29.13°C) of daily maximum temperature (Tmax) distribution, indicating that the risk of CH was higher when exposed to both ambient heat and PM2.5 at the same time compared to exposure to a single risk factor.

Conclusion

Exposure to higher levels of PM2.5 and ambient heat during pregnancy increases the risk of CH in infants. There was a positive interaction between exposure to intense heat and high concentration of PM2.5 on the occurrence of CH.

A Neonatal Case of Lower Urinary Tract Obstruction and Imperforate Anus: Urethral Decompression Due to Rectourinary Fistula

Lower urinary tract obstruction (LUTO) is a rare fetal condition associated with significant perinatal morbidity and mortality. Herein, we report a neonatal case of LUTO with anal atresia complicated by anhydramnios and pulmonary hypoplasia. After treatment for severe postnatal respiratory distress, the neonate underwent vesicostomy and colostomy. Postoperatively, respiratory status and renal function improved. This case highlights a unique feature where a large rectovesical fistula channeled fetal urine into the colon, which minimized obstructive damage to the urinary tract and preserved renal morphology. Fetal colonic dilatation and numerous enteroliths indicate urine influx into the intestinal tract. Our case suggests the importance of recognizing such exceptions in complete LUTO to predict postnatal outcomes diagnosed in utero.

Congenital anomalies of the kidney and urinary tract: antenatal diagnosis, management and counselling of families

Congenital anomalies of the kidney and urinary tract are collectively one of the most commonly diagnosed antenatal conditions. Clinicians have several tools available to diagnose anomalies, including imaging, biomarkers, family history and genetic studies. In certain cases, antenatal interventions such as vesico-amniotic shunting may be considered to improve postnatal outcomes.Congenital kidney anomalies detected antenatally can vary in clinical significance from almost no impact postnatally to significant morbidity and perinatal mortality. Prognosis broadly depends on kidney size, structure and amount of amniotic fluid, alongside genetics and family history, and progression on subsequent scans. It is important to counsel parents appropriately using a parent-focused and personalised approach. The use of a multidisciplinary team should always be considered.

Clinical assessment of the fetal right Quantitative Lung Index

OBJECTIVES

We have previously described gestational-age-independent sonographic indices to assess fetal lung size in the right and left lungs: The Quantitative Lung Index for the right lung (QLI-R) and for the left lung (QLI-L), respectively. The purpose of this study was to evaluate the clinical cutoff point of the QLI-R to predict pulmonary hypoplasia and neonatal death.

MATERIALS AND METHODS

Retrospective assessment of the QLI-R in patients with left-sided congenital diaphragmatic hernia (CDH-L) and other fetal conditions at risk for fetal pulmonary hypoplasia. Cross-section and longitudinal assessment of the behavior of the QLI-R in untreated and treated patients. ROC curve analysis to determine the optimal cutoff point of the QLI-R in predicting neonatal death.

RESULTS

One hundred eighteen patients with CDH-L and other fetal conditions at risk for pulmonary hypoplasia had QLI-R measurements done. Seventeen patients were excluded for various reasons. Eleven patients with conditions other than CDH-L but at risk for pulmonary hypoplasia were used for intraclass coefficient measurements of the QLI-R. Ninety patients had CDH-L, of which 78 did not undergo antenatal intervention and in which the cutoff point for pulmonary hypoplasia and neonatal demise was assessed. Stent tracheal occlusion was performed in the remaining 12 patients with CDH-L, in which the behavior of the QLI after surgery was assessed. Analysis of the ICC showed an overall intra-rater reliability of 0.985 (Cronbach's Alpha-based). There was no correlation between gestational age and QLI-R (-0.73, Pearson correlation, p = .72). Twenty-six of the 78 patients (33%) with CDH-L managed expectantly had a neonatal demise. A QLI-R equal to or less than 0.45 was significantly predictive of neonatal demise (area under the curve 0.64, p = .046, sensitivity 77%). Nine of the 12 patients (75%) that underwent tracheal occlusion had neonatal survival. Of these, 10 had serial assessments of the QLI-R after surgery. An increase in the QLI-R of 0.11 was associated with a tendency for neonatal survival (p = .056).

CONCLUSION

Our study confirms that the QLI-R is a gestational-age-independent measurement of fetal lung size, with a high degree of reproducibility. In a population of expectantly managed CDH-L patients, a cutoff value of the QLI-R of 0.45 or lower is predictive of neonatal death from pulmonary hypoplasia. The QLI-R can be used to monitor fetal lung growth after tracheal occlusion, and an increase in the QLI-R is suggestive of neonatal survival. Further prospective studies are needed to confirm these findings and to explore the use of the QLI in other populations at risk for pulmonary hypoplasia and consequent neonatal demise.

Lower Urinary Tract Obstruction in Newborns

Lower urinary tract obstruction (LUTO) is a rare birth defect with a prevalence between 1 in 5,000 and 1 in 25,000 pregnancies. LUTO is one of the most common causes of congenital abnormalities of the renal tract. Several genetic conditions have been associated with LUTO. Most common causes of LUTO are posterior urethral valves and urethral atresia. Despite available prenatal and postnatal treatments, LUTO is a significant cause of morbidity and mortality in newborns causing significant end stage renal disease and pulmonary hypoplasia.

Perioperative pharmacological interventions for fetal immobilisation during fetal surgery and invasive procedures

BACKGROUND

Developments in ultrasound assessment of pregnancy has resulted in the increasing diagnosis of antenatal fetal issues. Many structural fetal conditions as well as complications associated with multiple pregnancies have the potential for in-utero treatment to improve both pregnancy and neonatal outcomes. Procedures such as laser ablation for twin-twin syndrome or cord occlusion for selective fetal termination require fetal immobilisation. Immobilisation of the fetus can occur through administration of medication to the mother or directly to the fetus. This improves procedural success and reduces the ongoing risk to the pregnancy. Evidence regarding the best medication and mode of delivery helps to ensure the optimal decision is made for both the mother and the fetus.

OBJECTIVES

To assess the effects of perioperative pharmacological interventions for fetal immobilisation during fetal surgery and invasive procedures on fetal, neonatal, and maternal outcomes.  SEARCH METHODS: We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (10 May 2021), and reference lists of retrieved studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs (including published abstracts) which compared different classes of medication administered to the mother or fetus to allow in-utero procedures to be performed. We also included cluster-randomised trials but excluded cross-over trials.

DATA COLLECTION AND ANALYSIS

We used the standard Cochrane Pregnancy and Childbirth methods for data collection and analysis. Two review authors independently assessed trials for inclusion and risk of bias, extracted data, and checked them for accuracy.

MAIN RESULTS

One study with three trial reports met the inclusion criteria. This involved 54 women with a multiple pregnancy. The study was conducted in a tertiary European hospital maternal-fetal medicine unit and compared remifentanil to diazepam for fetal immobilisation and maternal sedation during fetoscopic surgery.   Low-certainty evidence suggested that remifentanil may reduce fetal movement more than diazepam for two outcomes of fetal movement, one of fetal immobilisation at 40 minutes using a visual analogue score (VAS) (where 0 = immobile and 100 = baseline mobility), and one of gross body and limb movements (score was absolute number of movements), both assessed by a sonographer evaluating a taped ultrasound sequence (mean difference (MD) -65.00, 95% confidence interval (CI) -69.38 to -60.62 and MD -10.00, 95% CI -11.62 to -8.38; 1 study, 50 women).  Surgeons may also report being more satisfied with the procedure when using remifentanil rather than diazepam (risk ratio (RR) 2.88, 95% CI 1.60 to 5.15; 1 study, 50 women; low-certainty evidence). However, maternal respiratory rate may decrease more during the surgical procedure with remifentanil compared with diazepam (MD -6.00, 95% CI -8.29 to -3.71; 1 study, 50 women; low-certainty evidence). Maternal sedation may also be worse with remifentanil compared with diazepam (RR 0.09, 95% CI 0.01 to 0.65; 1 study, 50 women; low-certainty evidence) measured using an observer assessment of alertness/sedation (where a score of < 4 equates to profound sedation and > 4 equates to insufficient sedation). Perinatal mortality and time taken to perform the procedure were not reported in the trial.  We prespecified 20 outcomes and planned to use GRADE for 6 of them, all other outcomes were not able to be reported against for the purpose of meta-analysis due to data not being provided or unable to be interpreted. We assessed the included study at low risk of selection bias (appropriate random sequence generation and allocation concealment), performance bias (blinding of participants and personnel), detection bias (outcome assessors were blinded), attrition bias (incomplete outcome data minimal), and reporting bias.  Our GRADE assessment for certainty of the evidence indicates that there is low certainty of the evidence.

AUTHORS' CONCLUSIONS

We were only able to include one study with a small number of women, from a single centre, a European tertiary hospital. This study was published in 2005 with an abstract of this trial published in 2004. This study evaluated two intravenous medications administered to the mother - remifentanil and diazepam. This study reported our prespecified primary outcome but only evaluated several of our secondary outcomes, which limited further assessment. Low-certainty evidence suggested that remifentanil may be better at reducing fetal movements and surgeons were more satisfied with the procedure. However, maternal sedation and depression of breathing may be worse with remifentanil.  Further high-quality RCTs assessing both fetal and maternal medications are required to evaluate their efficacy for fetal immobilisation as well as safety for both mother and fetus.

Genome-Wide Survey for Microdeletions or -Duplications in 155 Patients with Lower Urinary Tract Obstructions (LUTO)

Lower urinary tract obstruction (LUTO) is, in most cases, caused by anatomical blockage of the bladder outlet. The most common form are posterior urethral valves (PUVs), a male-limited phenotype. Here, we surveyed the genome of 155 LUTO patients to identify disease-causing CNVs. Raw intensity data were collected for CNVs detected in LUTO patients and 4.392 healthy controls using CNVPartition, QuantiSNP and PennCNV. Overlapping CNVs between patients and controls were discarded. Additional filtering implicated CNV frequency in the database of genomic variants, gene content and final visual inspection detecting 37 ultra-rare CNVs. After, prioritization qPCR analysis confirmed 3 microduplications, all detected in PUV patients. One microduplication (5q23.2) occurred de novo in the two remaining microduplications found on chromosome 1p36.21 and 10q23.31. Parental DNA was not available for segregation analysis. All three duplications comprised 11 coding genes: four human specific lncRNA and one microRNA. Three coding genes (FBLIM1, SLC16A12, SNCAIP) and the microRNA MIR107 have previously been shown to be expressed in the developing urinary tract of mouse embryos. We propose that duplications, rare or de novo, contribute to PUV formation, a male-limited phenotype.

Therapeutic intervention for fetal lower urinary tract obstruction: Current evidence and future strategies

In-utero vesica-amniotic shunting for fetal lower urinary obstruction (LUTO) is known to improve perinatal survival. More recently, studies including centres performing fetal cystoscopy, have suggested benefit on longer-term survival and renal outcome - within the limitations of small numbers and limited follow-up. These interventions carry significant risk, and therefore patient selection, and optimal timing, are key. The aim of this article is to explore ways of improving the accuracy of prenatal diagnosis, and of identifying risk factors for fetal and postnatal renal failure. The next step is that of using established staging and classification systems to select the patient group that may benefit from intervention, based on published outcomes. Several factors come into play when selecting the timing of intervention, especially if the aim is that of renal, and not only pulmonary, preservation. Lastly, current technologies and their shortfalls are discussed.

Postnatal Management in Congenital Lower Urinary Tract Obstruction With and Without Prenatal Vesicoamniotic Shunt

Purpose: Congenital lower urinary tract obstruction (cLUTO) includes a heterogeneous group of conditions caused by a functional or mechanical outlet obstruction. Early vesicoamniotic shunting (VAS) possibly reduces the burden of renal impairment. Postpartum, pediatric urologists are confronted with neonates who have a shunt in place and a potentially impassable urethra with a narrow caliber. Early management of these patients can be challenging. Here, we would like to share the approach we have developed over time. Materials and Methods: We conducted a single-center retrospective analysis from 2016 to 2020 and included all patients diagnosed with cLUTO. Data focusing on time point and type of intervention was collected. Furthermore, patients with temporary diversion via a percutaneous VAS were selected for a more detailed review. Results: In total, 71 cases of cLUTO were identified during the study period. Within this group, 31 neonates received postnatal management and surgical intervention in our center. VAS was performed in 55% of these cases (N = 17). The postnatal treatment varied between transurethral or suprapubic catheterization and early Blocksom vesicostomy. In five infants with VAS, the urinary drainage was secured through the existing VAS by inserting a gastric tube (N = 1) or a 4.8 Fr JJ-stent (N = 4). To our knowledge, this is the first report of a stent-in-stent scheme, which can remain indwelling until the definite treatment. Conclusion: Having a secure urine drainage through a VAS allows the often premature infant to grow until definite surgery can be performed. This avoids placing a vesicostomy, which requires anesthesia.

Decreased biventricular myocardial deformation in fetuses with lower urinary tract obstruction

BACKGROUND

To observe myocardial deformations in fetuses with isolated lower urinary tract obstruction (LUTO) and identify the correlation between myocardial deformation and the severity of obstruction.

METHODS

The strain (S), strain rate in systole (SRs) and strain rate in diastole (SRd) of the left and right ventricles at the first examination were prospectively analyzed and compared between fetuses with isolated LUTO and gestational age (GA)-matched normal control fetuses. Multiple regression analyses were used to assess the obstructive factors for impaired strain and strain rate, and the independent variables included bladder volume, sum of the bilateral pelvic diameters, sum of the bilateral ureteral diameters, mean bilateral renal artery pulsatility index, and amniotic fluid index.

RESULTS

Thirty-six fetuses with isolated LUTO and 36 normal controls were enrolled. Overall, decreased S, SRs and SRd of both ventricles were noted in fetuses with LUTO (p < 0.001). Moreover, S and SR were significantly negatively related to distended bladder volume (p < 0.001).

CONCLUSIONS

Fetuses with LUTO demonstrated decreased left and right myocardial deformation, and this impaired cardiac dysfunction was correlated with the urinary bladder volume. Evaluating the myocardial deformation in fetal LUTO could provide information to aid in parental counselling and intervention monitoring.

Foetal therapies and their influence on preterm birth

Foetal therapy aims to improve perinatal survival or to prevent severe long-term handicap. Foetal medicine opens a new territory by treating the foetus as a patient. The mother has nothing to gain in terms of health benefits, yet she is inherently also undergoing treatment. In utero foetal interventions can be divided into ultrasound-guided minimally invasive procedures, fetoscopic procedures and open hysterotomy procedures, which carry an inherent risk of ruptured membranes and preterm birth. In this review, we summarise the conditions that may benefit from foetal therapy and review the current therapies on offer, each with their associated risk of ruptured membrane and preterm birth. We also look into some risk limiting and preventative strategies to mitigate these complications.