Takashi Yorifuji’s research while affiliated with Okayama University of Science and other places

The aim of this study is to compare long-term health outcomes between IVF-conceived children and non-IVF-conceived children in Japan, in the context of strong recommendation for single embryo transfer. Using data from a nationwide birth cohort linked with perinatal database, this study analyzed 2140 children born in Japan in May 2010. It compared child health and development outcomes up to 9 years of age between IVF-conceived and non-IVF-conceived children (binary exposure). A Poisson regression with robust variance to estimate the risk ratios for the association between IVF and various long-term child health and developmental outcomes. After adjusting for confounding factors, no significant differences were observed between IVF-conceived and naturally conceived children for most outcomes, including hospitalization, obesity, and developmental milestones. IVF-conceived children showed a slightly lower risk of attention problems at 8 years (adjusted Risk Ratio [aRR]: 0.73, 95% CI: 0.53–1.00). In subgroup analyses, IVF-conceived term children and singletons demonstrated reduced risk of cognitive delays at 5.5 years (aRR: 0.31, 95% CI: 0.10–0.96 and aRR: 0.37, 95% CI: 0.14–0.98, respectively). Conclusion: In this Japanese cohort, IVF conception was not associated with adverse long-term health or developmental outcomes. These findings provide reassurance about the safety of IVF, particularly in the context of single embryo transfer policies. Further research is needed to explore specific IVF protocols and subgroups. What is known: • Long-term health and developmental outcomes of IVF-conceived children remain inconsistent across studies and populations, despite the widespread use of this technology. What is new: • A nationwide population-based cohort study in Japan did not show adverse effects of IVF on long-term child health and development through age 9. • These findings provide reassurance about the safety of IVF, while indicating the need for careful monitoring in specific subgroups such as preterm and multiple births.

Background: Despite the lack of evidence supporting the use of chest compression-only cardiopulmonary resuscitation (CO-CPR) emphasizing the importance of rescue breathing for pediatric out-of-hospital cardiac arrest (OHCA), prehospital CO-CPR is increasing. The COVID-19 pandemic may have led more bystanders to perform CO-CPR, even for pediatric OHCA. However, studies on the dissemination of CO-CPR and outcomes in pediatric OHCA are limited. Hypothesis: Spread of CO-CPR led to increased mortality in pediatric OHCA. Aims: Investigate the mortality of nationwide pediatric OHCA patients with the dissemination of CO-CPR pre- and post-COVID-19. Methods: We conducted a retrospective study using a Utstein-Style population cohort database (Japanese National Registry). Pediatric OHCA patients (≤17 years old) with bystander resuscitation attempts registered between the pre-COVID-19 era (2017-2019) and the post-COVID-19 era (2020-2021) were included. The primary outcome was 30-day mortality after OHCA. The secondary outcome was 30-day poor neurological outcomes, defined as Cerebral Performance Category scores of 3, 4, or 5. We used Poisson regression with robust variance to estimate adjusted risk ratio (aRR) with 95% confidence interval (CI) and the population attributable fraction (PAF, %) with a focus on the post-COVID-19 period. Results: A total of 3,352 pediatric OHCA, 2,023 pre-COVID-19, and 1,329 post-COVID-19 patients received bystander CPR and were registered in the database. CO-CPR was more common than CPR with rescue breathing (RB-CPR) during the pre- and post-COVID-19 periods [pre-COVID-19: 1,356 (67.0%) vs. 667 (33.0%), post-COVID-19: 1,048 (78.9%) vs. 281 (21.1%)]. Comparison of CO-CPR vs. RB-CPR showed increased 30-day mortality in both periods [pre-COVID-19: 1,081/1,356 (79.7%) vs. 420/667 (63.0%), post-COVID-19: 841/1,048 (80.2%) vs. 181/281 (64.4%)]. In the overall cohort, mortality increased with CO-CPR (aRR: 1.16, 95% CI: 1.09-1.23, PAF:1.60%). Due to the increased number of patients receiving CO-CPR, we estimated 21.2 excess deaths over the two-year post-COVID-19 period. Similar results were observed for poor neurological outcome (aRR: 1.10, 95% CI: 1.05-1.16, PAF: 1.10%, excess poor outcome: 14.6]). Conclusion: With the spread of CO-CPR for pediatric OHCA, an estimated 10.6 excess deaths per year attributed to CO-CPR may have occurred in the post-COVID-19 period compared to the pre-COVID-19 period in Japan.

Injury recurrence in young children is a significant public health concern, as it may indicate an unfavorable home environment. This study evaluates whether infantile injuries increase recurrence during preschool years, contributing to more effective prevention strategies for vulnerable families. The study included 20,191 children from “The Longitudinal Survey of Babies in the 21st Century,” a representative sample of infants born in Japan between May 10 and 24, 2010. We conducted a logistic regression analysis to compare injury recurrence risk between children aged 18 months to seven years with and without infantile injury histories. The study revealed that infants with a history of injuries had a higher risk of subsequent hospital visits for injuries during preschool years (crude Odds Ratio (cOR) 1.52, 95% CI, 1.41–1.64, adjusted OR (aOR) 1.48, 95% CI 1.37–1.60). Specific injuries, such as falls (aOR 1.34, 95% CI, 1.26–1.43), pinches (aOR 1.22, 95% CI, 1.15–1.29), drowning (aOR 1.29, 95% CI, 1.19–1.40), ingestion (aOR 1.35, 95% CI, 1.17–1.55), and burns (aOR 1.47, 95% CI, 1.31–1.65), independently increased the risk of future injuries. Our findings highlight the necessity of universal safety measures in the home environment and targeted interventions for families with a history of high-risk injuries.

Aim This study investigated the association between outdoor play habits during preschool and school‐age obesity. Methods We conducted a longitudinal cohort study of all children born in Japan during 2 weeks in January and July 2001. We defined outdoor play habits at age 2.5 years (third survey) as exposure, while parent‐reported height and weight at age 7 years (seventh survey) were defined as overweight and obesity status using the WHO reference. Logistic regression models were used to estimate odds ratios (ORs) for associations between preschool outdoor play habits and school‐age obesity, adjusting for parental and child factors. Results Of 53 575 children born, 42 812 had data on outdoor play habits at age 2.5 years, with 91% (38 970) having such habits. At age 7 years, 31 743/42 812 (74%) children had height and weight data, with 3249/31 743 (10%) classified as overweight or obesity (BMI SD score ≥1.0). Outdoor play habits were negatively associated with obesity (adjusted OR 0.85, 95% confidence interval (CI): 0.74–0.97). Conclusion Outdoor play habits in early preschool years are associated with a reduced risk of school‐age obesity. Parents and caregivers may consider encouraging their children to outdoor play habits at an early age to help prevent obesity later in life.

Background Previous research has suggested a correlation between postnatal maximum weight loss (MWL) and both neonatal mortality and morbidities in extremely preterm infants. However, the relationship between MWL and neurodevelopmental outcomes remains underexplored. Methods In a single-center, retrospective cohort study at Okayama Medical Center, we evaluated data from extremely preterm infants admitted to the neonatal intensive care unit from 2010 to 2020. Infants who died within the first 10 days of life were excluded. MWL in the first 10 days was the main exposure, categorized into three groups: >15%, 5–15%, and < 5%. The primary outcome evaluated was the occurrence of death or neurodevelopmental impairment (NDI) at age 3 years, defined as developmental impairments (developmental quotient [DQ] < 85), cerebral palsy, hearing impairments, or visual impairments. Data analysis involved robust Poisson regression, adjusted for perinatal confounders, with a restricted cubic spline function to examine the dose-response relationship. We also conducted a sensitivity analysis using a DQ of < 70 to define developmental impairment. Results Among 135 infants assessed for neurodevelopmental outcomes, 40 were in the > 15% MWL group, 71 in the 5–15% group, and 24 in the < 5% group. Median gestational ages and birth weights were 25.9 weeks and 821 g for > 15% MWL; 26.1 weeks and 818 g for 5–15% MWL; and 26.0 weeks and 734 g for < 5% MWL. Compared with the 5–15% MWL group, the < 5% group exhibited a higher risk of death or NDI at age 3 years (62.8% vs. 80.8%, risk ratio [RR] 1.36, 95% confidence interval [CI] 1.04–1.79) and NDI alone (59.2% vs. 79.2%, RR 1.43, 95% CI 1.06–1.94). Furthermore, higher risks of developmental impairment were also noted in the > 15% (RR 1.32, 95% CI 1.00–1.75) and < 5% (RR 1.46, 95% CI 1.08–1.98) groups. These associations were confirmed by spline analyses. In contrast, the associations between MWL and neurodevelopmental outcomes using a DQ of < 70 were not apparent. Conclusions MWL within the first 10 days of life may be associated with increased risks of NDI and developmental impairments by age 3 years in extremely preterm infants.

Background: In 2013, Japan established a standardized classification system for categorizing endoscopic sinus surgery (ESS) into types I-V, yet no evaluation has been conducted thereof. Objective: We assessed the ESS trends and status in Japan, focusing on outpatient and inpatient surgeries. Material and methods: This descriptive retrospective cohort study used Japan's National Database of Health Insurance Claims and Specific Health Checkups between 2014 and 2021. The distribution of ESS types I-V and outpatient and inpatient surgeries was analysed, along with age groups and regional differences, focusing on ESS type III. Results: Overall, 427,813 ESS procedures were performed, with types III and IV being most common. Outpatient ESS type III increased substantially compared to inpatient surgeries. Younger individuals favoured outpatient ESS type III over inpatient surgeries, with substantial regional variations across prefectures. Conclusions and significance: The adoption of a standardized ESS classification in Japan has facilitated a detailed understanding of surgical trends. The shift toward outpatient surgeries, especially for type III ESS, aligns with global trends toward minimally invasive procedures and reflects changing patient preferences and healthcare delivery practices. Consequently, continuous monitoring and research are crucial for adapting surgical practices to the evolving healthcare needs and patient expectations.