Novel scoring system for determining fetal candidacy for prenatal intervention for severe congenital lower urinary tract obstruction

Predictors of advanced chronic kidney disease in infancy after definitive vesicoamniotic shunting for congenital lower urinary tract obstruction

“…Figure 2 provides the odds ratios (OR) for perinatal characteristics impacting the development of CKD stage 4-5 by 12 months of age, including: bladder volume, unfavorable fetal electrolytes, gestational age and birth weight. When studied as a dichotomous variable, 3 or more unfavorable markers and initial bladder volume > 40 ml were used as the thresholds for comparison, as suggested by the scoring system for determining candidacy for fetal intervention by Nassr et al (17). As shown, only gestational age less than 35 weeks was a significant predictor of advanced CKD, with an OR of 17.5.…”

“…The threshold of approximately 5 months of age is similar to that identified by Coleman and colleagues in a non-shunted group of boys with PUV only (13). Of note, in a different study of shunted patients with severe cLUTO, the authors defined normal kidney function as a SCr <0.5 mg/dl at 6 months of age (17). This definition, if adopted in our study, would have included infants who would be estimated to have CKD 2-3 at 1 year.…”

“…Only with a more detailed understanding of patient subpopulations and the impact of intervention can we betterdefine who may benefit from intervention and in what ways. Of the multiple published staging algorithms and scoring systems, fetal bladder volume is characterized as high-risk across a range from 5.4 to 35 to 40 cm 3 (ml) (4,17,20). While our study included patients with a median volume of 39 cm 3 at the highest end of that spectrum, the IQR reflects the inconsistency in these thresholds.…”

“…While our study included patients with a median volume of 39 cm 3 at the highest end of that spectrum, the IQR reflects the inconsistency in these thresholds. Even more provocative has been the finding that the subgroup of patients with VAS showed a reduced sensitivity of the fetal intervention candidacy scoring system (17), which may suggest that the intervention changes the outcome or at least the character of the biomarker. Also variably understood, oligohydramnios is used to distinguish intervention candidates, while normal amniotic fluid volume in the second-trimester is nonetheless associated with ESKD by 2 years of age in up to one-third of cLUTO cases (35).…”

“…Perinatal characteristics were recorded, including: gestational age at cLUTO diagnosis, VAS placement and birth, bladder volume and presence of oligohydramnios at diagnosis, neonatal weight and length, need for positive pressure ventilation and intensive care length of stay. Fetal urine electrolytes were analyzed from the initial vesicocentesis, consistent with the center protocol at that time, with the following considered to be unfavorable: sodium >100 mmol/L, calcium >8 mg/L, chloride >90 mmol/L, osmolarity >200 mOsm/L, β-2 microglobulin >6 mg/L, protein >20 mg/dL (17). The biochemical markers collected in the study period included SCr at its neonatal peak or maximum rise after birth, at discharge from the intensive care unit at a time deemed appropriate by the medical care team, and at 1 to 3-month intervals throughout the first year of life to determine the nadir SCr or lowest recorded level.…”