OBJECTIVE:To evaluate the association of intraventricular hemorrhage-neuroprotection bundle (IVH-NB) implementation on intraventricular hemorrhage (IVH) rates in infants born at <29 weeks' gestation. STUDY DESIGN:This multicenter, retrospective, preimplantation and postimplementation cohort study included neonates of <29 weeks' gestation admitted to Canadian neonatal intensive care units (NICUs) participating in the Canadian Neonatal Network. Sites which implemented IVH-NB were identified via a survey. Data were collected for 36 months each for preimplantation and postimplementation periods per NICU, with 1-month washout. Infants with major anomalies or admitted >2 days after birth were excluded. Primary outcome was a composite of severe IVH (grade III/IV) or death ≤ first 7 days. Secondary outcomes included severe IVH, posthemorrhagic ventricular dilatation, and severe neurological injury (severe IVH or periventricular leukomalacia). RESULTS:Seventeen NICUs that implemented IVH-NB were included, contributing a total of 6522 infants (3216 preimplementation and 3306 postimplementation). Postimplementation, deferred cord clamping (56% vs 62%, P < .0001), prophylactic indomethacin (15% vs 19%, P < .0001), and normothermia (50% vs 56%, P < .0001) increased, and cardiopulmonary resuscitation (29% vs 25%, P < .0001) and endotracheal intubation at birth decreased (46% vs 41%, P < .0001). After implementation, aOR for the composite outcome (aOR 1.07, 95% CI 0.84, 1.35), severe IVH (aOR 1.02, 95% CI 0.80, 1.31), and posthemorrhagic ventricular dilatation (aOR 1.18 95% CI 0.78, 1.79) were unchanged. The only bundle component associated with improved outcomes was early patent ductus arteriosus treatment adopted by 2 sites (aOR 0.30, 95% CI 0.17, 0.55). No temporal trend in outcomes was identified. CONCLUSION:In this large multicenter cohort, IVH-NB implementation was associated with improved practices but not with improved outcomes.

Importance Clinical observations of immediate improvement in fraction of inspired oxygen (FiO 2 ) in a proportion of cases is often cited as the rationale for using inhaled nitric oxide (iNO) in the management of acute pulmonary hypertension among very preterm neonates (gestational age, <32 weeks). However, the clinical effectiveness of such a response pattern remains underinvestigated. Objective To identify factors associated with predischarge mortality among very preterm neonates receiving iNO for acute pulmonary hypertension, with specific a priori emphasis on iNO responsiveness. Design, Setting, and Participants This prospective observational cohort study was conducted from January 1, 2018, to December 31, 2022, at 12 Canadian tertiary neonatal intensive care units. Consecutive very preterm neonates who received iNO for a diagnosis of acute pulmonary hypertension and pretreatment FiO 2 of 0.50 or more were included. Neonates with congenital anomalies or those who were treated for chronic pulmonary hypertension with iNO were excluded. Early acute pulmonary hypertension (≤72 hours of age) and late acute pulmonary hypertension (>72 hours of age) cohorts were analyzed separately. Statistical analysis was performed from January 2023 to January 2024. Exposure Treatment with iNO for acute pulmonary hypertension. Main Outcomes and Measures The study cohorts were divided for comparison based on the primary outcome of predischarge mortality. Logistic regression analyses were used with predefined variables, including iNO responsiveness, to identify factors associated with mortality. A positive response to iNO was defined as a pre-iNO minus 4-hour post-iNO FiO 2 of 0.20 or more. Results The early acute pulmonary hypertension group (mean [SD] birth gestational age, 26.3 [2.4] weeks; median treatment age, 1 day [IQR, 1-2 days]; 147 boys [56%]) included 262 neonates; 179 (68%) had a pre-iNO FiO 2 of 1.0. The late acute pulmonary hypertension group (mean [SD] birth gestational age, 24.9 [1.7] weeks; median treatment age, 13 days [IQR, 9-20 days]; 72 boys [66%]) included 109 neonates; 51 (47%) had a pre-iNO FiO 2 of 1.0. Neonates with early acute pulmonary hypertension more frequently had a positive iNO response (71% [186 of 262] vs 41% [45 of 109]) and lower mortality (34% [90 of 262] vs 49% [53 of 109]) than those with late acute pulmonary hypertension. Accounting for pretreatment illness factors, greater reduction in FiO 2 with iNO remained associated with lower mortality for neonates with early acute pulmonary hypertension (adjusted odds ratio per FiO 2 reduction of 0.10, 0.74 [95% CI, 0.65-0.84]). For those with late acute pulmonary hypertension, however, only pretreatment illness severity (lower pre-iNO FiO 2 and higher pre-iNO pH), and not positive response to iNO (adjusted odds ratio, 0.47 [95% CI, 0.17-1.30]), was associated with mortality. Conclusions and Relevance In this cohort study of very preterm neonates with acute pulmonary hypertension treated with iNO, responsiveness to iNO was associated with improved outcomes during the first 72 hours of age. The prognostic role of iNO response in acute pulmonary hypertension presenting after 72 hours of age remains unclear. Future studies should investigate the distinct pathophysiological mechanisms associated with late acute pulmonary hypertension in this population.

BACKGROUND:Deferred cord clamping reduces mortality in preterm infants. However, there is a controversy about whether deferred cord clamping is as effective in cesarean delivery as in vaginal delivery. OBJECTIVE:This study aimed to compare the mortality and short-term outcomes of extremely preterm singleton infants who received deferred cord clamping after cesarean delivery with those who received deferred cord clamping after vaginal delivery and those who received early cord clamping after cesarean delivery. STUDY DESIGN:A national retrospective review of maternal, perinatal, and neonatal data of preterm infants born at <29 weeks of gestation who were admitted to units participating in the Canadian Neonatal Network between January 2015 and December 2022 was conducted. The rates and trends of deferred cord clamping (≥ 30 seconds) were evaluated, and the outcomes of infants who received deferred cord clamping after cesarean delivery were compared with (a) those who received deferred cord clamping after vaginal delivery and (b) those who received early cord clamping (<30 seconds) after caesarean delivery. The primary outcome was hospital mortality/severe brain injury (defined as grade 3/4 intraventricular hemorrhage and/or periventricular leukomalacia). Multivariate regression models with generalized estimating equations were used to account for clustering of infants within each site after adjusting for potential confounders. RESULTS:Of 6137 infants included in the study, 1952 (31.8%) received deferred cord clamping after cesarean delivery, 1804 (29.4%) received deferred cord clamping after vaginal delivery, and 2381 (38.8%) received early cord clamping after cesarean delivery at a median gestational age of 27 (interquartile range, 25-28), 26 (interquartile range, 25-28) and 26 (interquartile range, 25-28) weeks, respectively. There was a slow increase in the practice of deferred cord clamping in cesarean delivery from 32% in 2015 to approximately 50% in 2021-2022. After adjustment for potential confounders, infants who received deferred cord clamping after cesarean delivery had lower odds of a composite of mortality/severe brain injury (281/1952 [14%]) than those who received deferred cord clamping after vaginal delivery (347/1804 [19%]; adjusted odds ratio, 0.69 [95% confidence interval, 0.54-0.87]) and those who received early cord clamping after cesarean delivery (543/2381 [23%]; adjusted odds ratio, 0.69 [95% confidence interval, 0.57-0.83]). Deferred cord clamping after cesarean delivery was not associated with changes in other adverse short-term outcomes. CONCLUSION:Deferred cord clamping was associated with a reduction in a composite of mortality/severe brain injury in singleton preterm infants born at <29 weeks of gestation via cesarean delivery.

To determine maternal, neonatal, and hospital factors influencing deferred cord clamping (DCC) compliance rates in preterm neonates. Neonates born <33 weeks’ gestational age (GA) within the Neonatal Intensive Care Units of Canadian Neonatal Network during 2018–2022 were included. Units’ DCC quality improvement (QI) efforts were surveyed. The factors were stratified by <15 seconds (s) immediate cord clamping, 15–59 s early cord clamping, or ≥60 s DCC. Of 16,217 eligible neonates, only 45

Introduction: Optimal oxygen saturation targets remain unknown for extremely preterm infants. Methods: Cohort analysis of eligible preterm infants born <29 weeks’ gestation admitted between 2011 and 2018 to centers submitting data to the Canadian Neonatal Network (CNN) database. Site questionnaires to determine saturation targets, alarm settings, and date of change, allowed assignation of centers to intermediate (88–93%) or high (90–95%) saturation targets. A 6-month washout period was applied to sites which switched targets during the study period. Our primary outcome was survival free of major morbidity. Secondary outcomes were death, necrotizing enterocolitis (NEC), bronchopulmonary dysplasia (BPD), treated retinopathy of prematurity, and evidence of brain injury during admission. Generalized estimating equations were applied to compensate for demographic differences and site practices. Results: There were 2,739 infants in the high (mean gestational age [GA] 26 ± 1.6 weeks) and 6,813 infants in the intermediate (mean GA 26.2 ± 1.6 weeks) saturation target group. Survival without morbidity was higher in the intermediate target group (adjusted odds ratio [aOR] 1.59; 95% CI: 1.04, 2.45). There was no difference in mortality between groups (aOR 0.81; 95% CI: 0.59, 1.11), in NEC, treated retinopathy, or brain injury. On subgroup analysis, restricting data to sites which switched targets during the study, intermediate saturation targets were associated with lower rates of BPD (aOR 0.45; 95% CI: 0.28, 0.72). Conclusion: For neonates <29 weeks’ gestation, intermediate saturation target was associated with higher odds of survival without major morbidity compared to higher oxygen saturation target.

AIM:Umbilical venous catheters (UVC) have been associated with an increased risk of necrotizing enterocolitis (NEC). We aimed to assess the relationship between the type of initial central venous access in preterm infants and NEC. METHODS:Using the Canadian Neonatal Network database, we identified preterm infants <30 weeks gestation born between 2014 and 2021 in one of 32 participating centres who had a peripherally inserted central catheter (PICC) as initial vascular access. These infants were matched in a 1:1 ratio based on gestational age, sex and birth weight to infants in two other groups: (i) those who initially had an UVC and (ii) those who had an UVC followed by a PICC. RESULTS:A total of 497 infants were included in this study: 165 in the PICC group, 164 in the UVC group and 165 in the UVC + PICC group. There was no association between the type of initial central venous access and NEC. CONCLUSION:Although this retrospective study did not find an association between the type of initial central venous access and NEC, larger prospective studies are required to evaluate this association.

Background Excessive antimicrobial exposure is associated with an increase in neonatal mortality, morbidities and adverse neurodevelopment. Canadian Neonatal Network has been promoting judicious antimicrobial use through the Evidence-based Practice for Improving Quality processes. Our objective was to evaluate the antimicrobial consumption among neonates in tertiary neonatal intensive care units (NICU) in Canada in the recent decade. Methods This is a retrospective cohort study including data from very preterm infants (born at <33 weeks gestational age) admitted to all NICUs in Canada between January 1, 2013, and December 31, 2022. Nationwide antimicrobial utilization rate (AUR) benchmarking started in 2016, and quality improvement initiatives were continued in the subsequent years to promote judicious use of antimicrobials across the network. AUR is defined as the number of days with >= 1 antimicrobial divided by the total patient days (PD). Culture-proven sepsis refers to a neonate with positive culture of pathogens in blood and/or cerebrospinal fl uid. The outcomes were evaluated during pre- (2013-2017) and post-intervention periods (2018-2022). Interrupted time-series analysis was used, and comparison of AUR calculated per each 3-month time block and the slope changes were conducted across the pre- and post-intervention periods regarding total patients and subgroups. Findings A total of 41,253 infants were included, with 22,644 (55%) being male. The AUR was significantly lower among infants from the post- vs. those from the pre-intervention periods (152 vs. 184, p < 0.0001). Among 35,670 infants without culture-proven sepsis or necrotizing enterocolitis >= Stage 2, AUR was significantly lower in the post-intervention group vs. the pre-intervention group (110 vs. 136, p < 0.0001). Interrupted time-series showed significant reduction in AUR during both pre- and post-intervention periods among all infants with and without culture proven sepsis or necrotizing enterocolitis >= Stage 2 (all p < 0.0001), as well as those born at <29 weeks gestational age. Interpretation A comprehensive, network-wide quality improvement initiatives led to a significant and sustained reduction in antimicrobial use among preterm infants born at <33 weeks gestational age with and without culture-proven sepsis or necrotizing enterocolitis >= Stage 2.

BACKGROUND: One of the controversies regarding the management of twin gestations relates to the mode of delivery. Currently, counseling regarding the mode of delivery and the chance of successful vaginal twin delivery is based on the average risk for intrapartum cesarean delivery in the general population of twin pregnancies. Decision support tools that provide an individualized risk for intrapartum cesarean delivery based on the unique characteristics of each patient can improve counseling and decision-making regarding the choice of mode of delivery in twin pregnancies. OBJECTIVE: This study aimed to develop and validate a prediction model to determine the risk for intrapartum cesarean delivery in twin pregnancies. STUDY DESIGN: In this secondary analysis of the Twin Birth Study, a multicenter randomized controlled trial, we considered the subgroup of individuals who underwent a trial of vaginal delivery. Candidate predictors included maternal age, parity, previous cesarean delivery, conception method, chorionicity, diabetes and hypertension in pregnancy, gestational age at birth, the onset of labor, presentation of the second twin, sonographic fetal weight estimation, and fetal sex. The co-primary outcomes were overall intrapartum cesarean delivery and cesarean delivery of the second twin. Multivariable logistic regression models were used to estimate the probability of the study outcomes. Model performance was evaluated using measures of discrimination (the area under the receiver operating characteristic curve), calibration, and predictive accuracy. Internal validation was performed using the bootstrap resampling technique. RESULTS: A total of 1221 individuals met the study criteria. The rate of overall intrapartum cesarean delivery and cesarean delivery for the second twin was 25.4% and 5.7%, respectively. The most contributory predictor variables were nulliparity, term birth (>= 37 weeks), a non- cephalic presentation of the second twin, previous cesarean delivery, and labor induction. The models for overall intrapartum cesarean delivery and cesarean delivery of the second twin had good overall discriminatory accuracy (area under the receiver operating characteristic curve, 0.720; 95% confidence interval, 0.688-0.752 and 0.736; 95% confidence interval, 0.669-0.803, respectively) and calibration (as illustrated by the calibration plot and Brier scores of 0.168; 95% confidence interval, 0.156-0.180 and 0.051; 95% confidence interval, 0.040-0.061, respectively). The models achieved good specificity (66.7% and 81.6%, respectively), high negative predictive value (86.0% and 96.9%, respectively), and moderate sensitivity (68.1% and 57.1%, respectively). CONCLUSION: The prediction models developed in this study may assist care providers in counseling individuals regarding the optimal timing and mode of delivery in twin pregnancies by providing individualized estimates of the risk for intrapartum cesarean delivery.

A microfabricated nanobubble-based sensor was developed for real-time physiological pressure monitoring. The fully immersed sensor utilizes an electrolytic bubble generated and localized within a microfluidic channel that is in communication with the local environment. Bubble size varies with local pressure changes, allowing pressure to be monitored by tracking the resulting electrochemical impedance changes. An asymmetric electrode pair bubble generator design achieved precise picoliter-volume bubble control using either oxygen or hydrogen gas. Precise pressure monitoring down to a resolution of 1 mmHg (0.13-kPa) was achieved using long-lasting (>4 hours) oxygen bubbles tracked under a quasi-stable regime bounded by distinct, traceable bubble-channel wall detachment interac- tions. This corresponds to a $20\times $ improvement in resolution compared to microbubble-based pressure sensors reported to date. [2023-0077]

BACKGROUND:Antenatal detection of accelerated fetal growth and macrosomia in pregnancies complicated by diabetes mellitus is important for patient counseling and management. Sonographic fetal weight estimation is the most commonly used tool to predict birthweight and macrosomia. However, the predictive accuracy of sonographic fetal weight estimation for these outcomes is limited. In addition, an up-to-date sonographic fetal weight estimation is often unavailable before birth. This may result in a failure to identify macrosomia, especially in pregnancies complicated by diabetes mellitus where care providers might underestimate fetal growth rate. Therefore, there is a need for better tools to detect and alert care providers to the potential risk of accelerated fetal growth and macrosomia. OBJECTIVE:This study aimed to develop and validate prediction models for birthweight and macrosomia in pregnancies complicated by diabetes mellitus. STUDY DESIGN:This was a completed retrospective cohort study of all patients with a singleton live birth at ≥36 weeks of gestation complicated by preexisting or gestational diabetes mellitus observed at a single tertiary center between January 2011 and May 2022. Candidate predictors included maternal age, parity, type of diabetes mellitus, information from the most recent sonographic fetal weight estimation (including estimated fetal weight, abdominal circumference z score, head circumference-to-abdomen circumference z score ratio, and amniotic fluid), fetal sex, and the interval between ultrasound examination and birth. The study outcomes were macrosomia (defined as birthweights >4000 and >4500 g), large for gestational age (defined as a birthweight >90th percentile for gestational age), and birthweight (in grams). Multivariable logistic regression models were used to estimate the probability of dichotomous outcomes, and multivariable linear regression models were used to estimate birthweight. Model discrimination and predictive accuracy were calculated. Internal validation was performed using the bootstrap resampling technique. RESULTS:A total of 2465 patients met the study criteria. Most patients had gestational diabetes mellitus (90%), 6% of patients had type 2 diabetes mellitus, and 4% of patients had type 1 diabetes mellitus. The overall proportions of infants with birthweights >4000 g, >4500 g, and >90th percentile for gestational age were 8%, 1%, and 12%, respectively. The most contributory predictor variables were estimated fetal weight, abdominal circumference z score, ultrasound examination to birth interval, and type of diabetes mellitus. The models for the 3 dichotomous outcomes had high discriminative accuracy (area under the curve receiver operating characteristic curve, 0.929-0.979), which was higher than that achieved with estimated fetal weight alone (area under the curve receiver operating characteristic curve, 0.880-0.931). The predictive accuracy of the models had high sensitivity (87%-100%), specificity (84%-92%), and negative predictive values (84%-92%). The predictive accuracy of the model for birthweight had low systematic and random errors (0.6% and 7.5%, respectively), which were considerably smaller than the corresponding errors achieved with estimated fetal weight alone (-5.9% and 10.8%, respectively). The proportions of estimates within 5%, 10%, and 15% of the actual birthweight were high (52.3%, 82.9%, and 94.9%, respectively). CONCLUSION:The prediction models developed in the current study were associated with greater predictive accuracy for macrosomia, large for gestational age, and birthweight than the current standard of care that includes estimated fetal weight alone. These models may assist care providers in counseling patients regarding the optimal timing and mode of delivery.

( Am J Obstet Gynecol . 2023;228:326.e1–13) The rupture of membranes prior to labor (PROM) can be associated with dangerous complications. It is theorized that consistent monitoring and early induction can improve the outcome of women with PROM. The Term Prelabor Rupture of Membranes (TERMPROM) study is a study conducted to assess the effects and treatments of PROM. This study aimed to analyze and compare the TERMPROM study with the use of induction of labor (IOL) during pregnancy to reduce PROM effects.

OBJECTIVE:To compare 2% aqueous chlorhexidine gluconate (AQC) vs. 2% chlorhexidine gluconate in 70% isopropyl alcohol (ALC) for pre-venipuncture skin antisepsis in very-low-birth-weight neonates (VLBW, birth-weight <1500 grams). STUDY DESIGN:Double-blind, non-inferiority trial randomized 199 VLBW neonates, age 2-28 days, to receive pre-venipuncture skin preparation using single application of swabstick impregnated with AQC (n = 99) or ALC (n = 100). Skin clearance rate (percentage post-cleansing skin swabs with <15 bacterial colony forming units) with a 10% non-inferiority margin for AQC was primary outcome. Absolute and relative CFU reduction and adverse skin reactions were compared. RESULTS:AQC's clearance was non-inferior to ALC (91% vs. 88%; 95% CI -6.6%, +12.4%). Median (interquartile range) absolute [61 (16, 110) vs. 63 (18, 100); p = 0.65] and relative [100% (97%, 100%) vs. 100% (99.7%, 100%); p = 0.20] CFU reductions were similar. Neither group experienced any adverse reactions. CONCLUSION:AQC may provide non-inferior skin disinfection to ALC in VLBW neonates. CLINICAL TRIAL REGISTRATION:ClinicalTrials.gov NCT01270776.

Objectives To identify the predictors of successful first trial off nasal continuous positive airway pressure (nCPAP). Methods A retrospective cohort study of infants <= 29 weeks' gestation who required nCPAP for >24 h was conducted. Logistic regression was used to detect predictors for successful trial off nCPAP. Statistical analysis was performed using the SAS software. Results A total of 727 infants were included in the analysis. Infants who were successful in their first trial off nCPAP (n = 313) were of higher gestational age (GA) and birth weight (BW), as well as a higher proportion of female infants, compared with those who were not successful (p < 0.01). When stratified by GA, a negative correlation was noted between GA and postmenstrual age at successful trial off nCPAP or high flow nasal cannula (HFNC) (r = 0.45, p < 0.01). Logistic regression analysis showed that GA (odds ratio [OR] 1.13, 95% confidence interval [CI] [1.03-1.24], p = 0.01) and percentage of time spent with an oxygen saturation over 89% in the 24 h preceding the trial off nCPAP (OR 1.08, 95% CI [1.05-1.11], p = 0.00) were independent predictors for successful trial off nCPAP. Conclusion Successful trial off nCPAP or HFNC in preterm infants is significantly associated with higher GA, BW, female gender, and the specific oxygen saturation histogram in the preceding 24-h period.

A high-resolution Parylene-based pressure sensor with nanobubbles generated, localized, and monitored in realtime was tailored for in vivo monitoring. Using an asymmetric electrode pair, precise picoliter-volume oxygen bubbles were electrolytically generated and confined within an open microchannel configured for electrochemical impedance monitoring. Long-lasting (>4 hours) oxygen bubbles were coupled to a digital pressure source and an optical bubble tracking system to achieve a resolution of 1 mmHg (0.13 kPa). This resolution meets accuracy requirements for monitoring intracranial pressure (ICP), with a 0–20 mmHg range. The 20× resolution improvement corresponds to the best performance for a microfabricated bubble-based pressure sensor to date.

Objective To examine the association between probiotic use and antimicrobial utilization. Study design We retrospectively evaluated very-low-birth-weight (VLBW) infants admitted to tertiary neonatal intensive care units in Canada between 2014 and 2019. Our outcome was antimicrobial utilization rate (AUR) defined as number of days of antimicrobial exposure per 1000 patient-days. Result Of 16,223 eligible infants, 7279 (45%) received probiotics. Probiotic use rate increased from 10% in 2014 to 68% in 2019. The AUR was significantly lower in infants who received probiotics vs those who did not (107 vs 129 per 1000 patient-days, aRR = 0.89, 95% CI [0.81, 0.98]). Among 13,305 infants without culture-proven sepsis or necrotizing enterocolitis ≥Stage 2, 5931 (45%) received probiotics. Median AUR was significantly lower in the probiotic vs the no-probiotic group (78 vs 97 per 1000 patient-days, aRR = 0.85, 95% CI [0.74, 0.97]). Conclusion Probiotic use was associated with a significant reduction in AUR among VLBW infants.

Objective: To determine the rates and perinatal factors associated with initiation and early discontinuation of breastfeeding among very preterm neonates.Methods: This was a retrospective cohort study of very preterm infants (<29 weeks gestation) admitted to 2 regional Level III neonatal intensive care units (NICUs) from January 1, 2015, to December 31, 2019. A national neonatal database was used to evaluate initiation and continuation rates of breastfeeding and associated perinatal factors. Stored nutrition profiles and delivery record books were used to determine feeding volumes associated with continuation of breastfeeding to hospital discharge for a subgroup of infants at a single site. Descriptive and inferential statistics were used to present the results between groups, and logistic regression modeling was used to calculate crude and adjusted odds ratios (OR) and 95% CI.Results: Of 391 eligible neonates, 84% initiated breastfeeding but only 38% continued to discharge. Interestingly, frequency of breastfeeding initiation (P < 0.001) and continuation (P < 0.001) declined over the study period. After adjustment for confounders, younger maternal age, earlier gestational age, cigarette smoking, and multiparity were significantly associated with early discontinuation of breastfeeding prior to hospital discharge. Early discontinuation of breastfeeding was also related to lower volumes of breastmilk by day 7 of life (P = 0.004).Conclusion: Very preterm neonates are at high risk for non-initiation and early discontinuation of breastfeeding. The early postnatal period represents a critical time to establish breastmilk volumes, and the identification of key perinatal risk factors allows for early and targeted breastfeeding support.

Microfabricated devices for gas bubble generation via water electrolysis typically employ two electrodes of identical size ( $i$ . $e$ . interdigitated electrodes or microelectrode pairs). Contrary to this practice, asymmetrically sized electrode pairs offer distinct advantages in the formation of single, trapped nanoliter-volume gas bubbles in microfluidic devices. Although such principles may apply generally to MEMS or micro-scale water electrolysis devices, our model system consisted of a Parylene C microfluidic structure to contain the bubble and embedded thin-film Pt electrodes immersed in $1\times $ phosphate buffered saline solution. The geometric area of one microelectrode was constant (working electrode) while that of the second electrode (counter electrode) was varied over five orders of magnitude. Although increased counter electrode size increases overall device size, it provides improvements in various performance metrics. The largest tested counter electrode size resulted in 41% energy savings per bubble, improved bubble volume uniformity, enabled successful discrimination between O 2 versus H 2 gas generation, and achieved bubble stability exceeding 500 minutes (a $25\times $ improvement over previous work). The underlying theory motivating the use of asymmetric electrodes is detailed and followed by experimental demonstration. Finally, a discussion on tradeoffs to assist in the design of MEMS-based electrolytic bubble generation devices is provided. [2021-0172]

Objective To examine rates and determinants of home nasogastric (NG)-tube feeding at hospital discharge in a cohort of very preterm infants within the Canadian Neonatal Network (CNN). Study design This was a population-based cohort study of infants born <33 weeks of gestation and admitted to neonatal intensive care units (NICUs) participating in the CNN between January 1, 2010, and December 31, 2018. We excluded infants who had major congenital anomalies, required gastrostomy-tube, or were discharged to non-CNN facilities. Multivariable logistic regression analysis was used to identify independent determinants of home NG-tube feeding at hospital discharge. Results Among the 13 232 infants born very preterm during the study period, 333 (2.5%) were discharged home to receive NG-tube feeding. Rates of home NG-tube feeding varied across Canadian NICUs, from 0% to 12%. Determinants of home NG-tube feeding were gestational age (aOR 0.94 per each gestational week increase, 95% CI 0.88-0.99); duration of mechanical ventilation (aOR 1.02 per each day increase, 95% CI 1.01-1.02); high illness severity at birth (aOR 1.32, 95% CI 1.01-1.74); small for gestational age (aOR 2.06, 95% CI 1.52-2.78); male sex (aOR 0.61, 95% CI 0.49-0.77); severe brain injury (aOR 1.60, 95% CI 1.10-2.32); and bronchopulmonary dysplasia (aOR 2.22, 95% CI 1.67-2.94). Conclusions Rates of home NG-tube feeding varied widely between Canadian NICUs. Higher gestational age and male sex reduced the odds of discharge home to receive NG-tube feeding; and in contrast small for gestational age, severe brain injury, prolonged duration on mechanical ventilation and bronchopulmonary dysplasia increased the odds.

To evaluate change in the severity of hypoxic-ischemic encephalopathy (HIE) and associated morbidities between pre- and during COVID-19 pandemic periods in Canada. We conducted a retrospective cohort study extracting the data from level-3 NICUs participating in Canadian Neonatal Network (CNN). The primary outcome was a composite of death in the first week after birth and/or stage 3 HIE (Sarnat and Sarnat). Secondary outcomes included rate and severity of HIE among admitted neonates, overall mortality, brain injury on magnetic resonance imaging (MRI), neonates requiring resuscitation, organ dysfunction, and therapeutic hypothermia (TH) usage. We included 1591 neonates with gestational age ≥ 36 weeks with HIE during the specified periods: pandemic cohort from April 1st to December 31st of 2020; pre-pandemic cohort between April 1st and December 31st of 2017, 2018, and 2019. We calculated the odds ratio (OR) and confidence intervals (CI). We observed no significant difference in the primary outcome (15% vs. 16%; OR 1.08; 95%CI 0.78–1.48), mortality in the first week after birth (6% vs. 6%; OR 1.10, 95%CI 0.69–1.75), neonates requiring resuscitation, organ dysfunction, TH usage, or rate of brain injury. In the ad hoc analysis, per 1000 live births, there was an increase in the rate of infants with HIE and TH use. Severity of HIE, associated morbidities, and mortality were not significantly different during the pandemic lockdown compared to a pre-pandemic period in Canada. Anticipated risks and difficulties in accessing healthcare have not increased the mortality and morbidities in neonates with HIE in Canada.