Proactive Diagnosis and Tailor-Made Treatment of Patent Ductus Arteriosus in Very Preterm Infants with Routine Echocardiography in Japan: A post hoc Analysis of the PLASE Study.

INTRODUCTION: A feature of the management of extremely preterm infants in Japan is proactive circulatory management using early routine echocardiography performed by neonatologists. METHODS: This study was a post hoc analysis of the Patent ductus arteriosus and Left Atrial Size Evaluation in preterm infants (PLASE) study, which is a prospective cohort study including preterm infants admitted to 34 tertiary neonatal intensive care units in Japan between October 2015 and December 2016. We described the details of the treatment strategy of patent ductus arteriosus (PDA) based on early routine echocardiography. RESULTS: In total, 613 preterm infants were included into the analysis. Twenty percent of infants with prophylactic indomethacin were switched to therapeutic cyclooxygenase inhibitor (COX-I) before the completion of the full prophylactic indomethacin course. Therapeutic COX-I was mostly administered based on echocardiographic findings before PDA became symptomatic or hemodynamically significant. Therapeutic COX-I was frequently discontinued after one or two doses before the full course (three doses) was completed. The proportion of infants requiring additional treatment (additional therapeutic COX-I course or surgical PDA closure) after discontinued COX-I courses (<3 doses) compared to infants after completed 3 doses course was significantly lower (after the first therapeutic COX-I course 46% vs. 68%, p < 0.001) or without a significant difference (after the second or third course). CONCLUSIONS: The clinical management of PDA in Japan featured (1) COX-I administration based on echocardiographic findings before symptomatic or hemodynamically significant PDA appeared and (2) frequent discontinuation of therapeutic COX-I before completing the standard three doses course.

Biventricular function in preterm infants with patent ductus arteriosus ligation: A three-dimensional echocardiographic study.

BACKGROUND: The detailed hemodynamics after patent ductus arteriosus (PDA) ligation in preterm infants remain unknown. We aimed to clarify the effect of surgical ligation on left ventricular (LV) and right ventricular (RV) volume and function. METHODS: Echocardiography was performed in 41 preterm infants (median gestational age: 25 weeks) before and after PDA ligation. Global longitudinal strain was determined using three-dimensional speckle-tracking echocardiography. These values were compared with those in 36 preterm infants without PDA (non-PDA). RESULTS: Preoperatively, the PDA group had greater end-diastolic volume (EDV) and cardiac output (CO) in both ventricles, a higher LV ejection fraction (LVEF) (53% vs 44%) and LV global longitudinal strain, and a lower RVEF (47% vs 52%) than the non-PDA group. At 4-8 h postoperatively, the two groups had a similar LVEDV and RVEDV. However, the PDA group had a lower EF and CO in both ventricles than the non-PDA group. At 24-48 h postoperatively, the RVEF was increased, but the LVEF remained decreased, and LVCO was increased. CONCLUSIONS: PDA induces biventricular loading and functional abnormalities in preterm infants, and they dramatically change after surgery. Three-dimensional echocardiography may be beneficial to understand the status of both ventricles. IMPACT: Preterm infants are at high risk of hemodynamic compromise following a sudden change in loading conditions after PDA ligation. Three-dimensional echocardiography enables quantitative and serial evaluation of ventricular function and volume in preterm infants with PDA. PDA induces biventricular loading and functional abnormalities in preterm infants, and they dramatically change after surgery.

Modeling of multiple atrial septal defects with inferior vena cava rim deficiency: Three-dimensional visualization of the rim based on transthoracic echocardiographic imaging.

The morphologic features of the multiple atrial septal defects assessed by TTE-based 3D imaging were similar to those by 3D-TEE. TTE-based 3D model had excellent visibility, allowing observation of 3D structure of the rims of the defects. It may be useful method for assessment of the multiple atrial septal defects.

Impact of comprehensive quality improvement program on outcomes in very-low-birth-weight infants: A cluster-randomized controlled trial in Japan.

BACKGROUND: Differences in outcomes among neonatal intensive care units (NICUs) in Japan have been noted, prompting the need for quality improvement. AIM: To assess a comprehensive quality improvement program on outcomes in very-low-birth-weight (VLBW) infants. STUDY DESIGN: A cluster-randomized clinical trial. SUBJECTS: Forty hospitals and VLBW infants born in 2012-2014 and admitted to those hospitals were study subjects. OUTCOME MEASURES: The intervention group (IG) received a comprehensive quality improvement program involving clinical practice guidelines, educational outreach visits, workshops, opinion leader training, audits, and feedback. The control group (CG) was provided only with the guidelines. The primary outcome was survival without neurological impairment at three years of age. RESULTS: IG consisted of 19 hospitals and 1735 infants, while CG included 21 hospitals and 1700 infants. There were no significant differences in gestational weeks, 29.1(26.9-31.3) vs. 29.1(26.7-31.1) or birth weights (g), 1054(789-1298) vs. 1084(810-1309) between the two groups. Both groups showed survival rates without neurological impairment of 67.2 % (1166) and 66.9 % (1137), respectively, without a significant difference. There was no significant difference in mortalities at NICU discharge between the groups, with rates of 4.0 % (70) and 4.2 % (72) respectively. Several clinically relevant improvements were observed in IG, including reduced rates of sepsis, adrenal insufficiency, transfusion for anemia, and a shorter interval to achieve full enteral feeding. However, these did not lead to improvements in the primary outcome. CONCLUSION: The comprehensive quality improvement program to Japanese NICUs did not result in a significant improvement in survival without neurological impairment in VLBW infants.

Respiratory function testing for guiding ventilator mode conversion in congenital diaphragmatic hernia.

INTRODUCTION: For patients with a congenital diaphragmatic hernia, conventional mechanical ventilation (CMV) and high-frequency oscillatory ventilation (HFOV) are used in initial ventilatory management. HFOV has recently been recommended as a rescue therapy; however, we use HFOV for initial ventilation management, with a preoperative challenge test for CMV conversion and respiratory function testing at the time of CMV conversion. We aimed to compare patient characteristics between CMV conversion- and HFOV-preferred treatment groups. METHODS: Ventilator settings and blood gases were retrospectively evaluated pre- and post-CMV conversion, and respiratory function tests for compliance of the respiratory system (Crs) and for resistance of the respiratory system (Rrs) were performed during the trial to CMV conversion. RESULTS: No differences were observed between the CMV conversion- and HFOV-preferred groups regarding gestational age, birth weight, and observed/expected lung area-to-head circumference ratios. The median Crs (ml/cmH2 O/kg) and Rrs (cmH2 Oï½¥kg/L/s) in the CMV conversion- and HFOV-preferred groups was 0.42 versus 0.53 (p = .44) and 467 versus 327 (p = .045), respectively. The pre and posttrial amount of change in blood gas levels and ventilator parameters in the CMV conversion- and HFOV-preferred groups were as follows: mean airway pressure, -2.0 versus 0 cmH2 O; partial pressure of carbon dioxide, 6.1 versus 2.9 Torr; alveolar-arterial oxygen difference, -39.5 versus -50 Torr; and oxygenation index, -1.0 versus -0.6; respectively. CONCLUSION: Respiratory function tests were useful in tailoring ventilator settings. Patients with high Rrs values responded better to CMV conversion.

Death of children with Down syndrome by gestational age and cause.

BACKGROUND: We often encounter preterm infants with Down syndrome (DS) who die in the neonatal intensive care unit (NICU). In this study, we examined survival until NICU discharge and assessed the developmental prognosis of preterm infants with DS. METHODS: We retrospectively reviewed 416 infants with DS hospitalized during the past 27 years at our NICU. RESULTS: Death occurred in 8/20 (40%) infants at <32 weeks' gestation, 11/23 (48%) at 32-33 weeks, 9/99 (9%) at 34-36 weeks, and 9/274 (3%) at >36 weeks. In total, 84% of infants who died and 25% of those who survived had a non-reassuring fetal status (p < 0.001). Sex, small-for-gestational-age status, and postnatal transport were not associated with death. The main causes of death were bronchopulmonary dysplasia in 4/8 (50%) infants at <32 weeks' gestation, transient abnormal myelopoiesis in 11/20 (55%) and lymphatic dysplasia in 6/20 (30%) at 32-36 weeks, and varied causes at >36 weeks. Among survivors born at <34 weeks' gestation, 6/19 (32%) aged >2 years had moderate or severe cerebral palsy. CONCLUSIONS: These data on the high mortality and morbidity of preterm infants with DS may be useful for patient treatment and parent counseling in NICUs treating critically ill infants. IMPACT: Most infants with Down syndrome born at <34 weeks' gestation are born by cesarean section because of the non-reassuring fetal status. The mortality rate before discharge for infants with Down syndrome born at <34 weeks' gestation was 40%, and 30% of survivors developed moderate or severe cerebral palsy. The risk of death due to bronchopulmonary dysplasia and pulmonary hypertension was high in very preterm infants with Down syndrome despite the absence of chorioamnionitis. Infants with Down syndrome were born 1-2 weeks earlier than unaffected controls.

Assessment of pulmonary artery size at birth as a prognostic factor in congenital diaphragmatic hernia: results of a multicenter study in Japan.

OBJECTIVE: To assess the reliability of pulmonary artery (PA) parameters as a prognostic marker in neonates with isolated left-sided congenital diaphragmatic hernia (IL-CDH). STUDY DESIGN: A retrospective cohort study conducted by the Japanese CDH Study Group (JCDHSG). RESULTS: 323 IL-CDH patients registered with the JCDHSG were included. 272 patients survived to 90 days of age. Right PA (RPA) and left PA (LPA) diameters and pulmonary artery index (PAIndex) at birth were significantly larger in survivors. The cutoff values of RPA and LPA diameters and PAIndex for survival up to 90 days were 3.2 mm, 2.8 mm and 83.7, respectively, and logistic regression analysis showed that these were significantly related to survival. Multiple logistic regression analysis showed that both the PA parameters and liver herniation were significantly related to survival. CONCLUSIONS: The three PA parameters at birth can predict clinical outcomes and are considered as independent risk factors of liver herniation.

Common Blood Test Indices for Predicting Transient Abnormal Myelopoiesis-Related Mortality in Infants with Down Syndrome.

Transient abnormal myelopoiesis (TAM) can cause early death in children with Down syndrome, and liver failure is the most common cause of death. The aim of this single-center retrospective study was to identify a quantitative index for predicting TAM-related mortality at the time of diagnosis. Of the 462 children with Down syndrome admitted to our hospital from 1992 to 2021, we studied 12 infants with TAM-related death and 31 survivors who were diagnosed with TAM. In the death and survival groups, the median gestational ages were 34.9 and 37.1 weeks, respectively (p = 0.12). At diagnosis, the white blood cell (WBC) counts were 99.2 and 36.2 × 109/L (p = 0.011), the hemoglobin concentrations were 131 and 159 g/L (p = 0.009), and the serum albumin concentrations were 23 and 31 g/L (p < 0.001), respectively. The areas under the receiver operating characteristic curve for the abilities of the WBC count, hemoglobin, and serum albumin at diagnosis to predict survival were 0.75, 0.76, and 0.85, respectively. The serum albumin concentration threshold of 28 g/L at diagnosis had sensitivity of 0.79 and specificity of 0.82. Gestational age and serum albumin concentration were entered into a logistic regression model. The serum albumin concentration was an independent indicator of TAM-related death (adjusted odds ratio, 0.78; 95% confidence interval, 0.65-0.93; p = 0.005). In conclusion, a low serum albumin concentration at diagnosis may be a good predictor of TAM-related death.

Outcomes of congenital diaphragmatic hernia among preterm infants: inverse probability of treatment weighting analysis.

OBJECTIVES: To evaluate the survival and intact-survival rates among preterm infants with congenital diaphragm hernia (CDH). STUDY DESIGN: Multicenter retrospective cohort study of 849 infants born between 2006 and 2020 at 15 Japanese CDH study group facilities. Multivariate logistic regression analysis adjusted using inverse probability treatment weighting (IPTW) method was used. We also compare trends of intact-survival rates among term and preterm infants with CDH. RESULTS: After adjusting using the IPTW method for CDH severity, sex, APGAR score at 5 min, and cesarean delivery, gestational age and survival rates have a significantly positive correlation [coefficient of determination (COEF) 3.40, 95% confidence interval (CI), 1.58-5.21, p value <0.001] and higher intact-survival rate [COEF 2.39, 95% CI, 1.73-4.06, p value 0.005]. Trends of intact-survival rates for both preterm and term infants had significantly changed, but improvement in preterm infants was much smaller than in term infants. CONCLUSION: Prematurity was a significant risk factor for survival and intact-survival among infants with CDH, regardless of adjustment for CDH severity.

Right to left ventricular volume ratio is associated with mortality in congenital diaphragmatic hernia.

BACKGROUND: Congenital diaphragmatic hernia (CDH) is associated with high neonatal mortality. We performed this study to test the hypothesis that left ventricular (LV) and right ventricular (RV) volumes assessed by three-dimensional echocardiography may be associated with mortality in CDH. METHODS: This study was a single-center retrospective cohort study involving 35 infants with CDH. RV and LV end-diastolic volume (RVEDV and LVEDV, respectively) were measured by three-dimensional echocardiography and were corrected by birth body weight (BBW) on day 1. RVEDV/BBW, LVEDV/BBW, and LVEDV/RVEDV were compared between CDH survivors and non-survivors. Receiver-operating characteristic curve analysis was performed to assess the predictive ability for mortality of the echocardiographic parameters. RESULTS: Comparing CDH non-survivors (n = 6) with survivors (n = 29), respectively, RVEDV/BBW was significantly larger (2.54 ± 0.33 vs 1.86 ± 0.35 ml/kg; P < 0.01), LVEDV/BBW was significantly smaller (0.86 ± 0.21 vs 1.22 ± 0.33 ml/kg; P < 0.001), and LVEDV/RVEDV was significantly lower (0.34 ± 0.06 vs 0.66 ± 0.18; P < 0.001). The area under the curve for LVEDV/RVEDV was the largest (0.98). CONCLUSIONS: Three-dimensional echocardiographic volume imbalance between the RV and LV was remarkable in CDH non-survivors. The LVEDV/RVEDV ratio may be associated with mortality in CDH. IMPACT: Mortality with congenital diaphragmatic hernia (CDH) is high, and evaluating left and right ventricular structures and functions may be helpful in assessing the prognosis. Three-dimensional (3D) echocardiography indicated that the left ventricular end-diastolic volume/right ventricular end-diastolic volume ratio within 24 h after birth was associated with mortality in CDH infants. The usefulness of this ratio should be validated in prospective multicenter studies involving larger numbers of patients.

Development of mortality prediction models for infants with isolated, left-sided congenital diaphragmatic hernia before and after birth.

BACKGROUND: Mortality prediction of congenital diaphragmatic hernia (CDH) is essential for developing treatment strategies, including fetal therapy. Several researchers have reported prognostic factors for this rare but life-threatening condition; however, the optimal combination of prognostic factors remains to be elucidated. OBJECTIVES: This study aimed to develop the most discriminative prenatal and postnatal models to predict the mortality of infants with an isolated left-sided CDH. METHODS: This multi-institutional retrospective cohort study included infants with CDH born at 15 tertiary hospitals of the Japanese CDH Study Group between 2011 and 2016. We developed multivariable logistic models with every possible combination of predictors and identified models with the highest cross-validated area under the receiver operating characteristic curve (AUC) for prenatal and postnatal predictions. RESULTS: Among 302 eligible infants, 44 died before discharge. The prenatal mortality prediction model was based on the observed/expected lung area to head circumference ratio (O/E LHR), liver herniation, and stomach herniation (AUC, 0.830). The postnatal mortality prediction model was based on O/E LHR, liver herniation, and the lowest oxygenation index (AUC, 0.944). CONCLUSION: Our models can facilitate the prenatal and postnatal mortality prediction of infants with isolated left-sided CDH.

A predictive scoring system for small diaphragmatic defects in infants with congenital diaphragmatic hernia.

PURPOSE: To develop a predictive score for small diaphragmatic defects in infants with congenital diaphragmatic hernia (CDH) for determining thoracoscopic surgery indication. METHODS: The Japanese CDH Study Group cohort was randomly divided into derivation (n = 397) and validation (n = 396) datasets. Using logistic regression, a prediction model and weighted scoring system for small diaphragmatic defects were created from derivation dataset and validated with validation dataset. RESULTS: Six weighted variables were selected: no hydramnios, 1 point; 1 min Apgar score of 5-10, 1 point; apex type of the lung (left lung is detected radiographically in apex area), 1 point; oxygenation index < 8, 1 point; abdominal nasogastric tube (tip of the nasogastric tube is detected radiographically in the abdominal area), 2 points; no right-to-left flow of ductus arteriosus, 1 point. In validation dataset, rates of small diaphragmatic defects for Possible (0-3 points), Probable (4-5 points), and Definite (6-7 points) groups were 36%, 81%, and 94%, respectively (p < 0.001). Additionally, sensitivity, specificity, positive predictive value, and C statistics were 0.78, 0.79, 0.88, 0.76, and 0.45, 0.94, 0.94, 0.70 for Probable and Definite groups, respectively. CONCLUSION: Our scoring system effectively predicted small diaphragmatic defects in infants with CDH.

The efficacy of the postnatal nasogastric tube position as a prognostic marker of left-sided isolated congenital diaphragmatic hernia.

PURPOSE: The prenatal diagnosis of the stomach position in congenital diaphragmatic hernia (CDH) has been a reliable prognostic factor, but few studies have focused on the postnatal position. We therefore evaluated the significance of the nasogastric (NG) tube position just after birth. METHODS: The Japanese CDH Study Group database enrolled 1037 CDH neonates over 15 years. In our multicenter retrospective study, 464 cases of left-sided isolated CDH with prenatal diagnoses were divided into two groups: NG tube below the diaphragm (BD; n = 190) or above the diaphragm (AD; n = 274). The primary outcome was the 90-day survival rate, and the secondary outcomes were mechanical ventilation duration, hospitalization duration, and recurrence rate. RESULTS: The BD group had a significantly higher 90-day survival rate (98.4 vs. 89.4%, p < 0.001), shorter mechanical ventilation (11 vs. 19 days, p < 0.001), shorter hospitalization (38 vs. 59 days, p < 0.001), and lower recurrence rate (p = 0.002) than the AD group. A multivariate analysis showed that BD (adjusted odds ratio, 3.68; 95% confidence interval 1.02-13.30) was a favorable prognostic factor for the 90-day survival. CONCLUSION: The assessment of the NG tube position revealed it to be a reliable prognostic factor of left-sided isolated CDH. Therefore, it should be included as a routine assessment.

Prenatal predictors of mortality in fetuses with congenital diaphragmatic hernia: a systematic review and meta-analysis.

PURPOSE: This study aimed to evaluate prenatal predictors of mortality in fetuses with congenital diaphragmatic hernia (CDH). METHODS: A systematic literature search was performed to identify relevant observational studies that evaluated the ability of lung-to-head ratio (LHR), observed-to-expected LHR (o/e-LHR), observed-to-expected total fetal lung volume (o/e-TFLV), lung-to-thorax transverse area ratio (L/T ratio), intrathoracic herniation of the liver and the stomach, and side of diaphragmatic hernia, using a threshold for the prediction of mortality in fetuses with CDH. Study quality was assessed using the QUADAS-2 tool. Hierarchical summary receiver operating characteristic curves were constructed. RESULTS: A total of 50 articles were included in this meta-analysis. The QUADAS-2 tool identified a high risk of bias in more than one domain scored in all parameters. Among those parameters, the diagnostic odds ratio of mortality with o/e-LHR < 25%, o/e-TFLV < 25%, and L/T ratio < 0.08 were 11.98 [95% confidence interval (CI) 4.65-30.89], 11.14 (95% CI 5.19-23.89), and 10.28 (95% CI 3.38-31.31), respectively. The predictive values for mortality were similar between the presence of liver herniation and retrocardiac fetal stomach position. CONCLUSIONS: This systematic review suggests that o/e-LHR, o/e-TFLV, and L/T ratio are equally good predictors of neonatal mortality in fetuses with isolated CDH.

Long-Term Outcomes of Congenital Diaphragmatic Hernia: Report of a Multicenter Study in Japan.

BACKGROUND: Treatment modalities for neonates with congenital diaphragmatic hernia (CDH) have greatly improved in recent years, with a concomitant increase in survival. However, long-term outcomes restrict the identification of optimal care pathways for CDH survivors in adolescence and adulthood. Therefore, we evaluated the long-term outcomes within the Japanese CDH Study Group (JCDHSG). METHODS: Participants were born with CDH between 2006 and 2018 according to the JCDHSG. Participants were enrolled in the database at 1.5, 3, 6, and 12 years old. Follow-up items included long-term complications, operations for long-term complication, and home medical care. RESULTS: A total of 747 patients were included in this study, with 626 survivors (83.8%) and 121 non-survivors (16.2%). At 1.5, 3, 6, and 12 years old, 45.4%, 36.5%, 34.8%, and 43.6% developed complications, and 20.1%, 14.7%, 11.5%, and 5.1% of participants required home care, respectively. Recurrence, pneumonia, pneumothorax, gastroesophageal reflux disease, and intestinal obstruction decreased with age, and thoracic deformity increased with age. CONCLUSIONS: As CDH survival rates improve, there is a need for continued research and fine-tuning of long-term care to optimize appropriate surveillance and long-term follow-up.

Very low birth weight infants with congenital heart disease: A multicenter cohort study in Japan.

BACKGROUND: The frequency, mortality, and morbidity of very low birth weight (VLBW) infants with congenital heart disease (CHD) in Asian countries are limited. In addition, little is known about the risk factors of death in these infants. METHODS: A retrospective, multicenter cohort study was conducted. VLBW infants with CHD born between 2006 and 2010, and followed to 5 years of age, were included in the analysis. Multiple logistic regression analysis was performed to identify the risk factors of death. RESULTS: Among 3247 VLBW infants, 126 various CHDs (3.9 %) were identified. The most common lesions were ventricular septal defect, tetralogy of Fallot (TOF), and coarctation of the aorta/interrupted aortic arch, in that order. The proportions of left-sided and right-sided outflow obstruction (TOF, pulmonary stenosis) were 15.1 % and 15.9 %, respectively. Trisomy 18 and trisomy 13 were present in 32 (25.4 %) of 126 VLBW infants with CHD. Nine patients were lost to follow-up. Overall, 45 patients (35.7 %) died up to 5 years of age. Serious CHD [odds ratio (OR), 19.2; 95 % confidential interval (CI), 3.94-93.11; p < 0.0001], sepsis (OR, 42.3; 95 % CI, 5.39-332.22; p < 0.0001), chromosomal /named anomalies (OR, 7.50; 95%CI, 2.09-26.94; p = 0.001), and no-invasive treatments (OR, 9.89; 95%CI, 2.28-42.91; p = 0.001) were associated with death. On excluding chromosomal anomalies, twelve of 71 patients (16.9 %) died, and only sepsis (OR, 35.5, 95%CI, 2.63-477.1; p = 0.0008) was an independent risk factor. CONCLUSIONS: Trisomy 18 and trisomy 13 of chromosomal anomalies are frequently associated with VLBW infants with CHD. The mortality of VLBW infants with CHD is high, even when chromosomal anomalies are excluded. Sepsis has a significant impact on death in VLBW infants with CHD.

Changes in regional oxygen saturation of the kidney and brain of infants during hospitalization.

BACKGROUND: In pre-term infants, the postnatal changes in the regional oxygen saturation (rSO2) of the brain and kidney are unclear. METHODS: We performed a prospective observational study. We measured the cerebral/renal rSO2 ratio and recorded the associated clinical features of infants born at 23 to 41 weeks of gestation weekly from the early postnatal period to discharge. RESULTS: The median cerebral/renal rSO2 ratios (interquartile ranges) between birth and the expected date of birth were 1.13 (1.06-1.26) at 23-24 weeks (n = 7), 1.18 (1.10-1.32) at 25-26 weeks (n = 11), 1.24 (1.11-1.37) at 27-28 weeks (n = 9), 1.12 (1.05-1.19) at 29-30 weeks (n = 4), 1.11 (1.03-1.15) at 31-32 weeks (n = 5), 1.02 (0.98-1.06) at 33-34 weeks (n = 9), 0.98 (0.94-1.06) at 35-36 weeks (n = 19), and 0.95 (0.86-0.99) at 37-41 weeks of gestation (n = 22). The median cerebral/renal rSO2 ratio did not significantly change after birth, but with increasing gestational age, the cerebral/renal rSO2 ratio at the expected date of birth decreased (r = - 0.74, p < 0.001). Nephrotoxic drugs did not affect cerebral/renal rSO2 at the expected date of birth, after adjustment for clinical factors. CONCLUSIONS: Unlike in most infants born after the late pre-term period, the renal rSO2 remained lower than the cerebral rSO2 on the expected date of birth in infants born very pre-term.

Genome Analysis in Sick Neonates and Infants: High-yield Phenotypes and Contribution of Small Copy Number Variations.

OBJECTIVE: To delineate the diagnostic efficacy of medical exome, whole exome, and whole genome sequencing according to primary symptoms, the contribution of small copy number variations, and the impact of molecular diagnosis on clinical management. STUDY DESIGN: This was a prospective study of 17 tertiary care centers in Japan, conducted between April 2019 and March 2021. Critically ill neonates and infants less than 6 months of age were recruited in neonatal intensive care units and in outpatient clinics. The patients underwent medical exome, whole exome, or whole genome sequencing as the first tier of testing. Patients with negative results after medical exome or whole exome sequencing subsequently underwent whole genome sequencing. The impact of molecular diagnosis on clinical management was evaluated through contacting primary care physicians. RESULTS: Of the 85 patients, 41 (48%) had positive results. Based on the primary symptoms, patients with metabolic phenotypes had the highest diagnostic yield (67%, 4/6 patients), followed by renal (60%, 3/5 patients), and neurologic phenotypes (58%, 14/24 patients). Among them, 4 patients had pathogenic small copy number variations identified using whole genome sequencing. In the 41 patients with a molecular diagnosis, 20 (49%) had changes in clinical management. CONCLUSIONS: Genome analysis for critically ill neonates and infants had a high diagnostic yield for metabolic, renal, and neurologic phenotypes. Small copy number variations detected using whole genome sequencing contributed to the overall molecular diagnosis in 5% of all the patients. The resulting molecular diagnoses had a significant impact on clinical management.

Altered brain metabolite concentration and delayed neurodevelopment in preterm neonates.

BACKGROUND: A very-low-birth-weight (VLBW) preterm infants is associated with an increased risk of impaired neurodevelopmental outcomes. In this study, we investigated how neonatal brain metabolite concentrations changed with postmenstrual age and examined the relationship between changes in concentration (slopes) and neurodevelopmental level at 3-4 years. METHODS: We retrospectively examined 108 VLBW preterm infants who had brain single-voxel magnetic resonance spectroscopy at 34-42 weeks' postmenstrual age. Neurodevelopment was assessed using a developmental test, and subjects were classified into four groups: developmental quotient <70, 70-84, 85-100, and >100. One-way analyses of covariance and multiple-comparison post hoc tests were used to compare slopes. RESULTS: We observed correlations between postmenstrual age and the concentrations of N-acetylaspartate and N-acetylaspartylglutamate (tNAA) (p < 0.001); creatine and phosphocreatine (p < 0.001); glutamate and glutamine (p < 0.001); and myo-inositol (p = 0.049) in the deep gray matter; and tNAA (p < 0.001) in the centrum semiovale. A significant interaction was noted among the tNAA slopes of the four groups in the deep gray matter (p = 0.022), and we found a significant difference between the <70 and 85-100 groups (post hoc, p = 0.024). CONCLUSIONS: In VLBW preterm infants, the slopes of tNAA concentrations (adjusted for postmenstrual age) were associated with lower developmental quotients at 3-4 years. IMPACT: In very-low-birth-weight preterm-born infants, a slower increase in tNAA brain concentration at term-equivalent age was associated with poorer developmental outcomes at 3-4 years. The increase in tNAA concentration in very-low-birth-weight infants was slower in poorer developmental outcomes, and changes in tNAA concentration appeared to be more critical than changes in tCho for predicting developmental delays. While tNAA/tCho ratios were previously used to examine the correlation with neurodevelopment at 1-2 years, we used brain metabolite concentrations.