Journal of neonatal-perinatal medicine最新文献

{"title":"Salivary transcriptomic study to understand the molecular effects of feeding dysregulation in opioid-exposed neonates born late preterm.","authors":"Celia Rubien, William Lin, Marissa Chow, Francesca Carasi-Schwartz, Kiran Singh, Mario Cordova, Ronnelle King, Devika Lekshmi, Elizabeth Yen","doi":"10.1177/19345798261450464","DOIUrl":"10.1177/19345798261450464","url":null,"abstract":"<p><p>ObjectivesTo evaluate the effects of maternal opioid use on the expression of hypothalamic/reward genes involved in feeding regulation in late preterm neonates. We hypothesize that opioid use, rather than prematurity alone, is associated with feeding dysregulation and the need for tube feeding in this late preterm population.Study DesignIn this prospective, observational pilot study, the need for tube feeding was determined from subjects' medical records. The study population consisted of 39 opioid-exposed and 36 non-exposed neonates born at 34-37 weeks' gestation (late-preterm). Saliva was collected within 48 h of birth from the selected neonates; using RNA extraction and qPCR, the saliva was analyzed for select hypothalamic/reward and inflammatory genes involved in feeding regulation. The need for tube feeding (primary outcome) and salivary gene expression data (secondary outcome) were compared between the opioid-exposed and non-opioid exposed. Maternal and neonatal characteristics associated with increased need for tube feeding were explored using descriptive analyses.ResultsA significantly greater proportion of the opioid-exposed late preterm cohort, compared to non-exposed neonates, required tube feeding (51.2% vs 22.2%, p < 0.01). Opioid-exposed neonates also had lower expression of anorexigenic gene <i>POMC</i> (ΔCt 15.44 ± 2.76 vs 13.84 ± 4.03, p = 0.054), and this was accompanied by greater milk consumption in the first week of life (average of 24.2 mL/kg/day). Male sex, withdrawal severity, maternal polysubstance, and methadone use were associated with increased need for tube feeding.ConclusionModulation of hypothalamic/reward and inflammation genes may contribute to the need for tube feeding and its associated risks in opioid-exposed late preterm neonates.</p>","PeriodicalId":16537,"journal":{"name":"Journal of neonatal-perinatal medicine","volume":" ","pages":"676-686"},"PeriodicalIF":1.0,"publicationDate":"2026-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13366428/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147874312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Neonatal priapism revealing polycythemia: A rare association-Case report.","authors":"A Lalaoui, N Ranib, K Abi El Aala, G Kassal, F Bennaoui, N El Idrissi Slitine, F M R Maoulainine","doi":"10.1177/19345798261443961","DOIUrl":"10.1177/19345798261443961","url":null,"abstract":"<p><p>BackgroundNeonatal priapism is a rare and typically benign condition characterized by a persistent penile erection unrelated to stimulation. Unlike priapism beyond the neonatal period, which is more frequently ischemic, most neonatal cases are non-ischemic and idiopathic, although associations with polycythemia have been reported.Case presentationWe report the case of a male neonate born at 37 + 3 weeks of gestation who developed painless priapism on the first day of life, persisting for approximately 48 h. Clinical examination showed no penile discoloration or distress. Color Doppler ultrasound demonstrated preserved arterial and venous flow consistent with high-flow, non-ischemic priapism. A simple therapeutic phlebotomy was performed, resulting in complete detumescence within 24 h and normalization of hematologic parameters. The infant remained clinically stable, and 3-month follow-up showed no recurrence or complications.ConclusionThis case highlights the importance of considering polycythemia in the etiological assessment of neonatal priapism and supports a conservative approach when vascular flow is preserved. Early recognition and appropriate management can lead to favorable outcomes without long-term sequelae.</p>","PeriodicalId":16537,"journal":{"name":"Journal of neonatal-perinatal medicine","volume":" ","pages":"697-700"},"PeriodicalIF":1.0,"publicationDate":"2026-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147698937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Neonatal hydrometrocolpos secondary to vaginal atresia causing obstructive uropathy and renal dysfunction.","authors":"Ahmad Zohud, Hala O Abdallah, Hobab Jehad Odeh, Haneen Owienah, Amjad Rajab","doi":"10.1177/19345798261450462","DOIUrl":"10.1177/19345798261450462","url":null,"abstract":"<p><p>BackgroundHydrometrocolpos secondary to congenital vaginal atresia is a rare neonatal anomaly, usually diagnosed during puberty, resulting from obstructed uterovaginal secretions under maternal estrogen influence, which rarely leads to urinary tract compression, obstruction and renal dysfunction.Case presentationWe report a preterm 33-week neonatal Asian female delivered by normal vaginal delivery. Antenatal ultrasound revealed bilateral enlarged kidneys, ascites, and polyhydramnios. Postnatally, she developed sepsis, and elevated serum creatinine levels. Abdominal ultrasound and magnetic resonance imaging showed a cystic abdominopelvic mass with enlarged kidneys. Exploratory laparotomy confirmed congenital vaginal atresia. Following surgical intervention, the patient stabilized, with marked improvement in renal function.ConclusionAlthough congenital vaginal atresia is usually diagnosed at puberty, it can present in the neonatal period; early diagnosis and appropriate management are crucial to prevent complications and achieve favorable outcomes.</p>","PeriodicalId":16537,"journal":{"name":"Journal of neonatal-perinatal medicine","volume":" ","pages":"701-707"},"PeriodicalIF":1.0,"publicationDate":"2026-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147839185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"3-minute vs 10-minute Spontaneous Breathing Evaluations (SBE) for predicting extubation success in preterm very low birth weight infants: Retrospective observational study.","authors":"Juanitha George, Meriya Susan Joseph, Praveen C Samuel, Jayashree Purkayastha, Sandesh Kini","doi":"10.1177/19345798261450453","DOIUrl":"10.1177/19345798261450453","url":null,"abstract":"&lt;p&gt;&lt;p&gt;BackgroundExtubation in preterm very low birthweight (VLBW) infants is a critical step in respiratory management. Accurately predicting extubation success is challenging because of immature respiratory control, surfactant deficiency, and limited pulmonary reserve. The Spontaneous Breathing Evaluation (SBE) has emerged as an important bedside method to assess readiness for successful extubation, although the optimal duration of this evaluation remains uncertain.MethodsThis retrospective observational study included preterm neonates between 26 and 34 weeks of gestation with birthweight &lt;1500 g who required mechanical ventilation for more than 24 h in a tertiary NICU over a 12-month period. Infants who underwent SBE for either 3 min (Group B) or 10 min (Group A) as part of routine extubation readiness assessment were identified from clinical records. Group allocation was determined by a protocol change implemented mid-study period: infants assessed during the first 6 months underwent 10-min SBE, and those in the subsequent 6 months underwent 3-min SBE. The SBE was performed on endotracheal CPAP; failure criteria included sustained oxygen desaturation (SpO&lt;sub&gt;2&lt;/sub&gt; &lt;88% for &gt;10 s), bradycardia (heart rate &lt;100/min), apnoea requiring stimulation, or a requirement for increased FiO2 &gt;0.1 above baseline. Extubation decisions were based on SBE performance combined with clinical readiness criteria, including stable ventilator settings, acceptable blood gas parameters, and clinician judgment.ResultsEighty-eight infants met inclusion criteria (44 in each SBE-duration group). The mean gestational age was 29.9 ± 2.1 weeks and mean birthweight was 1168 ± 258 g. The Respiratory Severity Score (RSS; calculated as FiO&lt;sub&gt;2&lt;/sub&gt; × mean airway pressure) was significantly higher in the 10-min SBE group (1.85 ± 0.44 vs 1.67 ± 0.31; &lt;i&gt;p&lt;/i&gt; = 0.031), indicating greater baseline respiratory severity in that group. Overall, 84% of infants tolerated the SBE and 77% achieved extubation success, while extubation failure occurred in 23%. Most SBE failures occurred within the first 3 min, regardless of total SBE duration. On univariate analysis, birthweight &lt;1000 g (&lt;i&gt;p&lt;/i&gt; = 0.018) and gestational age &lt;28 weeks (&lt;i&gt;p&lt;/i&gt; = 0.040) were associated with lower likelihood of extubation success, and RSS &gt;2.1 strongly predicted reintubation. Multivariable logistic regression confirmed that gestational age &lt;28 weeks (OR 0.14, 95% CI 0.03-0.61; &lt;i&gt;p&lt;/i&gt; = 0.009) and RSS &gt;2.1 (OR 0.09, 95% CI 0.02-0.44; &lt;i&gt;p&lt;/i&gt; = 0.003) were independent predictors of extubation failure, while SBE duration was not independently associated with extubation outcome (&lt;i&gt;p&lt;/i&gt; = 0.412).ConclusionIn this hypothesis-generating retrospective study, a 3-min SBE demonstrated comparable performance to a 10-min SBE in predicting extubation success among preterm VLBW infants. Gestational maturity and RSS were stronger independent predictors of outcome. These findings require confirmation in larger pr","PeriodicalId":16537,"journal":{"name":"Journal of neonatal-perinatal medicine","volume":" ","pages":"687-696"},"PeriodicalIF":1.0,"publicationDate":"2026-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13669469/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147839234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Outcomes of the surviving co-twin after spontaneous single intrauterine demise in stage V twin-to-twin transfusion syndrome: A systematic review and meta-analysis.","authors":"Laura Fonseca Queiroz, Maria Julia Lemos, Berenice Curi-Pesantes, Davi Barbosa Pereira da Silva, Giovanna Cristina de Castro Martin, Iaci Luisa Lopes de Mattos, Bruna Benigna Sales Armstrong, Felipe Ruano Cruz, Gabriele Tonni, Rodrigo Ruano","doi":"10.1177/19345798261499676","DOIUrl":"https://doi.org/10.1177/19345798261499676","url":null,"abstract":"<p><p>ObjectivesThis review aims to estimate perinatal outcomes of co-twins following a single intrauterine fetal demise (IUFD) occurring in pregnancies complicated by spontaneous Stage V twin-to-twin transfusion syndrome (TTTS), focusing on gestational age at delivery, birth weight, and neonatal death.MethodsWe conducted a systematic review and single-arm meta-analysis following PRISMA guidelines and Cochrane methodology. PubMed, EMBASE, SCOPUS, Web of Science, and Cochrane Central Register of Controlled Trials (CENTRAL) were searched up to March 2026. Eligible studies included spontaneous TTTS Stage V pregnancies with reported outcomes for the surviving co-twins. Pooled analyses were performed using random-effects models, while outcomes unsuitable for quantitative pooling were summarized narratively. Heterogeneity was assessed using I² statistics.ResultsFive studies including 32 surviving co-twins were included. The mean gestational age at birth was 29.96 weeks (95% CI 26.80 to 33.12), and the pooled neonatal mortality rate was 33.33% (95% CI 18.97 to 51.65). Birth weight was reported in three studies including 21 surviving co-twins, with mean values ranging from 616.67 to 1691.10 g across studies.ConclusionStage V TTTS may be associated with prematurity, low birth weight, and high neonatal mortality rate. Given the very low certainty of evidence, findings should be interpreted as hypothesis-generating. Further prospective studies are needed to improve outcome counseling.</p>","PeriodicalId":16537,"journal":{"name":"Journal of neonatal-perinatal medicine","volume":" ","pages":"19345798261499676"},"PeriodicalIF":1.0,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149227987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Factors associated with persistent methicillin-resistant staphylococcal bacteremia after initiation of anti-MRSA therapy in the NICU: A retrospective observational study.","authors":"Takayuki Hirano, Naoki Egami, Go Ebihara, Kentaro Narazaki, Kazuaki Yasuoka, Yoshitomo Motomura, Hirosuke Inoue, Masayuki Ochiai, Yasunari Sakai","doi":"10.1177/19345798261499371","DOIUrl":"https://doi.org/10.1177/19345798261499371","url":null,"abstract":"<p><p>BackgroundMethicillin-resistant <i>Staphylococcus aureus</i> (MRSA) and methicillin-resistant coagulase-negative staphylococci (MRCoNS) are important causes of bacteremia in neonatal intensive care units (NICUs). However, clinical factors associated with persistent bacteremia after initiation of anti-MRSA therapy in NICU patients remain poorly defined.MethodsWe conducted a retrospective observational study of infants with MRSA or MRCoNS bacteremia admitted to a tertiary NICU between 2016 and 2025. Persistent bacteremia was defined as a positive follow-up blood culture on or after day 2 of initial anti-MRSA therapy. Multivariable logistic regression was performed to identify factors independently associated with persistent bacteremia.Results49 episodes of bacteremia were included, of which 16 (33%) met the criteria for persistent bacteremia. Younger postnatal age at bacteremia onset (adjusted odds ratio per 7-day decrease, 1.32; 95% confidence interval, 1.08-1.85; <i>p</i> = 0.001) and absence of central venous catheter removal or replacement within 2 days of starting initial anti-MRSA therapy (adjusted odds ratio, 11.20; 95% confidence interval, 2.16-86.60; <i>p</i> = 0.003) were independently associated with persistent bacteremia after initiation of anti-MRSA therapy.ConclusionsYounger postnatal age and the absence of central venous catheter removal or replacement were independently associated with persistent bacteremia after initiation of anti-MRSA therapy in NICU patients with MRSA or MRCoNS bacteremia. These findings may facilitate early identification of NICU patients at increased risk of persistent bacteremia and support closer monitoring and timely reassessment of treatment response. Prospective multicenter studies are warranted to validate these findings and establish optimal treatment strategies.</p>","PeriodicalId":16537,"journal":{"name":"Journal of neonatal-perinatal medicine","volume":" ","pages":"19345798261499371"},"PeriodicalIF":1.0,"publicationDate":"2026-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149194615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Office-hours versus off-hours deliveries among low-risk singleton pregnancies in Türkiye and early maternal and neonatal adverse outcomes: A retrospective cohort study.","authors":"Deniz Akyıldız, Betül Bay","doi":"10.1177/19345798261475325","DOIUrl":"https://doi.org/10.1177/19345798261475325","url":null,"abstract":"<p><p>BackgroundThe timing of birth may influence the quality and safety of obstetric care due to differences in staffing, workload, and clinical support. This study examined the association between office-hours and off-hours deliveries and early maternal and neonatal adverse outcomes.MethodsThis retrospective cohort study was conducted at a maternity hospital in Kahramanmaraş, Türkiye. Deliveries occurring between January 1, 2022, and January 1, 2023 were reviewed retrospectively. Births were classified as office-hours (08:00-15:59, Monday-Friday) or off-hours (16:00-07:59 on weekdays and all hours on weekends). Maternal and neonatal outcomes were compared between the groups using appropriate statistical tests, and odds ratios (ORs) with 95% confidence intervals (CIs) were calculated.ResultsA total of 1000 mother-newborn dyads were included, with 500 births occurring during office-hours and 500 during off-hours. Off-hours deliveries were associated with higher odds of intrapartum cesarean section (OR 2.27; 95% CI 1.02-5.04; <i>p</i> = 0.038) and episiotomy (OR 2.19; 95% CI 1.57-3.04; <i>p</i> < 0.001). Birth trauma was significantly less likely among births occurring during office-hours than among those occurring during off-hours (OR 0.28; 95% CI 0.09-0.85; <i>p</i> = 0.029). No significant differences were observed between the groups in postpartum haemorrhage, need for blood transfusion, or maternal death. Similarly, neonatal outcomes including low Apgar score at 5 min, respiratory distress, need for resuscitation, and admission to neonatal care did not differ significantly between the groups.ConclusionsBirths occurring during off-hours were associated with higher rates of intrapartum cesarean section, episiotomy, and birth trauma. These findings highlight the importance of ensuring consistent quality of obstetric care across all hours of service.</p>","PeriodicalId":16537,"journal":{"name":"Journal of neonatal-perinatal medicine","volume":" ","pages":"19345798261475325"},"PeriodicalIF":1.0,"publicationDate":"2026-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149110992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intratracheal budesonide combined with surfactant for respiratory distress syndrome in preterm infants: A randomized clinical trial.","authors":"Mohammad Kazem Sabzehei, Hanieh Talebi, Behnaz Basiri, Maryam Shokouhi Solgi, Roya Raeisi, Babak Jafarvand","doi":"10.1177/19345798261490894","DOIUrl":"https://doi.org/10.1177/19345798261490894","url":null,"abstract":"<p><p>BackgroundBronchopulmonary dysplasia (BPD) remains a major cause of morbidity among preterm infants with respiratory distress syndrome (RDS). Intratracheal budesonide combined with surfactant may reduce pulmonary inflammation and improve neonatal outcomes.MethodsIn this randomized clinical trial, 160 preterm infants (gestational age 26-32 weeks; birth weight <1500 g) requiring surfactant therapy for RDS were assigned to receive either surfactant alone (n = 80) or surfactant plus budesonide (0.25 mg/kg; <i>n</i> = 80). Primary outcomes were oxygen dependency or respiratory support beyond 21 days of life (the prespecified study respiratory outcome) and in-hospital mortality. Secondary outcomes included sepsis, intraventricular hemorrhage, necrotizing enterocolitis, retinopathy of prematurity, respiratory support duration, and repeat surfactant administration.ResultsBaseline characteristics were comparable between groups. The primary respiratory outcome occurred in 16/80 infants (20.0%) in the budesonide-surfactant group and 26/80 infants (32.5%) in the surfactant-alone group (absolute risk difference -12.5 percentage points; <i>P</i> = 0.105). Mortality was significantly lower in the combination group (1.2% vs 11.2%, <i>P</i> = 0.018), as was culture-proven sepsis (5.0% vs 21.2%, <i>P</i> = 0.004). Infants receiving budesonide required fewer repeat surfactant doses (38.8% vs 61.3%, <i>P</i> = 0.016) and had a shorter duration of nasal continuous positive airway pressure support (10.1 ± 6.0 vs 17.9 ± 11.3 days, <i>P</i> = 0.001). The composite outcome of death or oxygen dependency/respiratory support beyond 21 days of life occurred in 35 infants (43.8%) in the control group and 17 infants (21.3%) in the combination group (<i>P</i> = 0.003).ConclusionsIn preterm infants with RDS, budesonide-surfactant therapy was associated with reduced mortality, sepsis, respiratory support duration, and repeat surfactant use. Although fewer infants in the intervention group met the prespecified respiratory outcome, the difference was not statistically significant. Larger multicenter trials using contemporary BPD definitions and incorporating long-term neurodevelopmental follow-up are needed before efficacy and safety can be established.</p>","PeriodicalId":16537,"journal":{"name":"Journal of neonatal-perinatal medicine","volume":" ","pages":"19345798261490894"},"PeriodicalIF":1.0,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149075120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Beyond lung recruitment during HFOV: Characterizing the delivered oscillatory dose.","authors":"Emily Ostermaier, Weerapong Lilitwat","doi":"10.1177/19345798261489869","DOIUrl":"https://doi.org/10.1177/19345798261489869","url":null,"abstract":"","PeriodicalId":16537,"journal":{"name":"Journal of neonatal-perinatal medicine","volume":" ","pages":"19345798261489869"},"PeriodicalIF":1.0,"publicationDate":"2026-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148990226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Beyond single cause-of-death labels: A secondary analysis of outcome-specific latent-class phenotyping and marker-supported reclassification of stillbirths and neonatal deaths in Jordan.","authors":"Yousef Khader, Mohammad Alyahya","doi":"10.1177/19345798261490604","DOIUrl":"https://doi.org/10.1177/19345798261490604","url":null,"abstract":"<p><p>ObjectivesConventional perinatal death review assigns a principal cause despite overlapping pathways. We examined whether outcome-specific latent classes could complement conventional classification and whether structured markers could inform review of unexplained deaths.MethodsIn this secondary analysis, 588 expert-adjudicated deaths from 18 Jordanian hospitals (261 stillbirths, 327 neonatal deaths) were analyzed. Gestational age was modeled as mutually exclusive categories (<32, 32-36, ≥37 weeks) with eight outcome-specific binary markers. Model selection considered Bayesian information criterion (BIC), classification quality, parsimony, and stability to hospital omission and one-death-per-pregnancy resampling. Expert care-quality and preventability judgments were auxiliary outcomes. Marker hierarchies were applied to 192 unexplained/unclassifiable deaths.ResultsStillbirths supported one class (BIC 2357.4), stable in all sensitivity analyses. For neonatal deaths, two- and three-class BIC values were nearly identical (3398.8 vs 3397.6); the two-class solution had better classification quality and stability and was retained. It comprised a preterm respiratory/multiple-birth phenotype (n = 204) and a later-gestation congenital-asphyxial/sepsis phenotype (n = 123); definite preventability was 20.1% and 46.7%, respectively. Marker hierarchies assigned 149/192 deaths (77.6%) to marker-supported groups, leaving 43 (22.4%) unexplained.ConclusionsAvailable stillbirth indicators did not support latent subclasses. Neonatal deaths showed clinically interpretable heterogeneity, although class enumeration remained uncertain. Marker-supported grouping can recover residual clinical information but is order-dependent and does not establish cause or validate preventability.</p>","PeriodicalId":16537,"journal":{"name":"Journal of neonatal-perinatal medicine","volume":" ","pages":"19345798261490604"},"PeriodicalIF":1.0,"publicationDate":"2026-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148990171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}