Natural History of Fetal Lower Urinary Tract Obstruction with Normal Amniotic Fluid Volume at Initial Diagnosis.

OBJECTIVE: The aim of this study was to define the natural history of lower urinary tract obstruction (LUTO) with normal midgestational amniotic fluid volumes. MATERIALS AND METHODS: We performed a retrospective review of 32 consecutive patients with LUTO with normal midgestational amniotic fluid volume followed at 11 North American Fetal Therapy Network (NAFTNet) centers from August 2007 to May 2012. Normal amniotic fluid volume was defined as an amniotic fluid index (AFI) of ≥9 cm. RESULTS: The mean gestational age (GA) and AFI at enrollment were 23.1 ± 2.1 weeks and 15.8 ± 3.9 cm, respectively. The mean GA at delivery was 37.3 ± 2.8 weeks. The mean creatinine level at discharge was 1.2 ± 0.8 mg/dL. Perinatal survival was 97%. Twenty-five patients returned for serial postnatal assessment. Renal replacement therapy (RRT) was required in 32%. Development of oligohydramnios and/or anhydramnios, development of cortical renal cysts, posterior urethral valves, prematurity, and prolonged neonatal intensive care unit stay were associated with need for RRT (p < 0.05) by univariate analysis. By multivariate analysis, preterm delivery remained predictive of need for RRT (p = 0.004). CONCLUSION: Prenatal diagnosis of LUTO with normal midgestational amniotic fluid volumes is associated with acceptable renal function in the majority of patients. Approximately one-third of these children require RRT. Surrogate markers of disease severity appear to be predictive of need for RRT.

North American Fetal Therapy Network: intervention vs expectant management for stage I twin-twin transfusion syndrome.

BACKGROUND: Stage I twin-twin transfusion syndrome presents a management dilemma. Intervention may lead to procedure-related complications while expectant management risks deterioration. Insufficient data exist to inform decision-making. OBJECTIVE: The aim of this retrospective observational study was to describe the natural history of stage I twin-twin transfusion syndrome, to assess for predictors of disease behavior, and to compare pregnancy outcomes after intervention at stage I vs expectant management. STUDY DESIGN: Ten North American Fetal Therapy Network centers submitted well-documented cases of stage I twin-twin transfusion syndrome for analysis. Cases were retrospectively divided into 3 management strategies: those managed expectantly, those who underwent amnioreduction at stage I, and those who underwent laser therapy at stage I. Outcomes were categorized as no survivors, 1 survivor, 2 survivors, or at least 1 survivor to live birth, and good (twin live birth ≥30.0 weeks), mixed (single fetal demise or delivery between 26.0-29.9 weeks), and poor (double fetal demise or delivery <26.0 weeks) pregnancy outcomes. Outcomes were analyzed by initial management strategy. RESULTS: A total of 124 cases of stage I twin-twin transfusion syndrome were studied. In all, 49 (40%) cases were managed expectantly while 30 (24%) underwent amnioreduction and 45 (36%) underwent laser therapy at stage I. The overall fetal mortality rate was 20.2% (50 of 248 fetuses). Of those managed expectantly, 11 patients regressed (22%), 4 remained stage I (8%), 29 advanced in stage (60%), and 5 experienced spontaneous previable preterm birth (10%) during observation. The mean number of days from diagnosis of stage I to a change in status (progression, regression, loss, or delivery) was 11.1 (SD 14.3) days. Intervention by amniocentesis or laser therapy was associated with a lower risk of fetal loss (P = .01) than expectant management. The unadjusted odds of poor outcome were 0.33 (95% confidence interval, 0.09-01.20), for amnioreduction and 0.26 (95% confidence interval, 0.09-0.77) for laser therapy vs expectant management. Adjusting for nulliparity, recipient maximum vertical pocket, gestational age at diagnosis, and placenta location had negligible effect. Both amnioreduction and laser therapy at stage I decreased the likelihood of no survivors (odds ratio, 0.11; 95% confidence interval, 0.02-0.68 and odds ratio, 0.07; 95% confidence interval, 0.01-0.37, respectively). Only laser therapy, however, was protective against poor outcome in our data (odds ratio, 0.29; 95% confidence interval, 0.07-1.30 for amnioreduction vs odds ratio, 0.12, 95% confidence interval, 0.03-0.44 for laser), although the estimate for amnioreduction suggests a protective effect. CONCLUSION: Stage I twin-twin transfusion syndrome was associated with substantial fetal mortality. Spontaneous resolution was observed, although the majority of expectantly managed cases progressed. Progression was associated with a worse prognosis. Both amnioreduction and laser therapy decreased the chance of no survivors, and laser was particularly protective against poor outcome independent of multiple factors. Further studies are justified to corroborate these findings and to further define risk stratification and surveillance strategies for stage I disease.

Laser ablation of placental anastomoses in twin-to-twin transfusion syndrome: preoperative predictors of death by recursive partitioning.

OBJECTIVE: The aim of this study was to develop a simple clinical algorithm for prediction of donor and recipient death using 'yes'or 'no' questions through the process of recursive partitioning for patients undergoing laser therapy for twin to twin transfusion syndrome (TTTS). The intent was to identify a subset of patients with very high specificity to whom clinical decisions would be simplified. METHOD: Secondary analysis of data retrospectively collected from laser procedures was performed for TTTS at NAFTNet centers from 2002 to 2009. Preoperative factors associated with donor and recipient death were identified by recursive partitioning regression analysis. Classification And Regression Trees (CARTs) were developed to refine specificity for prediction of death. RESULTS: There were 466 TTTS patients from eight centers. CARTs were obtained for prediction of donor death. Improved specificity was achieved through recursive partitioning as demonstrated in receiver operator characteristic curves for prediction of death of the donor. There was less than optimal predictive ability for prediction of death in the recipient, as demonstrated by lack of generation of CARTs. CONCLUSION: Recursive partitioning improves the specificity and refines the prediction of donor fetal and neonatal demise in TTTS treated with laser therapy. This has the potential to improve therapeutic choices and refine counseling regarding outcomes.

The prenatal diagnosis of Beckwith-Wiedemann syndrome using ultrasound and magnetic resonance imaging.

Beckwith-Wiedemann syndrome is a rare congenital overgrowth syndrome. It carries important connotations for the pediatric urologist because it is associated with an increased risk for developing certain embryonal tumors. Until recently, these patients were not diagnosed until after birth; however, with newer imaging modalities, this syndrome may be diagnosed prenatally. We present a case of Beckwith-Wiedemann syndrome, depicting the prenatal modalities that may be used to diagnose this unusual condition.

Preoperative predictors of death in twin-to-twin transfusion syndrome treated with laser ablation of placental anastomoses.

OBJECTIVE: To determine preoperative predictive factors for donor and recipient death after laser ablation of placental vessels in twin-to-twin transfusion syndrome. STUDY DESIGN: Retrospective analysis of North American Fetal Therapy Network center laser procedures, 2002-2009. Factors associated with donor and recipient death were identified by regression analysis. RESULTS: There were 466 patients from 8 centers. Factors significantly associated with donor fetal death were low donor estimated fetal weight (odds ratio [OR], 0.69; 95% confidence interval [CI], 0.55-0.87) and reversed end diastolic velocity in the umbilical artery (OR, 4.0; 95% CI, 1.54-10.2); for recipient fetal death-low recipient estimated fetal weight (OR, 0.65; 95% CI, 0.44-0.95), recipient reversed "a" wave in the ductus venosus (OR, 2.39; 95% CI, 1.27-4.51) and hydrops (OR, 3.7; 95% CI, 1.1-12.7); for recipient neonatal death-low donor estimated fetal weight (OR, 0.54; 95% CI, 0.30-0.95), high recipient estimated fetal weight (OR, 1.55; 95% CI, 1.06-2.26) and recipient reversed end diastolic velocity in the umbilical artery (OR, 7.8; 95% CI, 1.03-59.3). CONCLUSION: Preoperative findings predict fetal and neonatal demise in twin-to-twin transfusion syndrome treated with laser therapy.