Horiuchi Sayaka, Shinohara Ryoji, Otawa Sanae, Kushima Megumi, Akiyama Yuka, Ooka Tadao, Kojima Reiji, Yokomichi Hiroshi, Miyake Kunio, Yamagata Zentaro
Center for Birth Cohort Studies University of Yamanashi Chuo-shi Japan.
Department of Health Sciences, School of Medicine University of Yamanashi Chuo-shi Japan.
Health Sci Rep. 2021 Oct 14;4(4):e421. doi: 10.1002/hsr2.421. eCollection 2021 Dec.
Early-term birth between 37 and 38 weeks of gestation increases the risk of mortality and morbidity. This study investigated the status and impact of early-term birth among neonates born by cesarean section in Japan.
All singleton live births that had data of gestational age at birth available in the Japan Environment and Children's Study (JECS), a nationwide birth cohort study launched in 2011, were eligible for this study. Neonates born by cesarean delivery at term without indications for early delivery were included to examine the association between early-term birth and respiratory distress at birth. The gestational age at birth was categorized as 37 weeks 0 day to 38 weeks 6 days (early-term), 39 weeks 0 day to 40 weeks 6 day (full-term), and 41 weeks 0 day to 41 weeks 6 days (late-term). Respiratory distress at birth included respiratory distress syndrome, transient tachypnea, and difficulty in breathing after birth. Univariable and multivariable analyses were performed using logistic regression models with a two-tailed significance level of 5%. All statistical analyses were performed using SAS, version 9.4, for Windows (SAS Institute, Cary, NC).
In total, 32 078 of 100 011 (32.1%) neonates had early-term birth. At 37 gestational weeks, 49.7% of the deliveries were via cesarean section, and half of the cesarean deliveries were due to a previous cesarean section. Among the 10 051 neonates born by elective cesarean delivery at term, neonates with early-term births were more likely to have respiratory distress at birth (adjusted odds ratio: 4.19; 95% confidence interval, 1.70, 10.34) than those born at full term.
Early-term birth is associated with a high risk of respiratory distress in births involving cesarean delivery without indication for early delivery. There is a need for guidelines for early delivery considering adverse effects of early-term births.
妊娠37至38周的早产会增加死亡和发病风险。本研究调查了日本剖宫产出生新生儿中的早产状况及其影响。
本研究纳入了2011年启动的全国性出生队列研究“日本环境与儿童研究”（JECS）中所有有出生孕周数据的单胎活产儿。纳入无早产指征的足月剖宫产出生的新生儿，以研究早产与出生时呼吸窘迫之间的关联。出生孕周分为37周0天至38周6天（早产）、39周0天至40周6天（足月）、41周0天至41周6天（过期产）。出生时的呼吸窘迫包括呼吸窘迫综合征、短暂性呼吸急促和出生后呼吸困难。使用逻辑回归模型进行单变量和多变量分析，双侧显著性水平为5%。所有统计分析均使用适用于Windows的SAS 9.4版软件（SAS Institute，北卡罗来纳州卡里）。
在100011例新生儿中，共有32078例（32.1%）为早产。在妊娠37周时，49.7%的分娩为剖宫产，其中一半的剖宫产是由于既往剖宫产史。在10051例足月择期剖宫产出生的新生儿中，早产新生儿出生时发生呼吸窘迫的可能性高于足月出生的新生儿（调整后的优势比：4.19；95%置信区间，1.70，10.34）。
在无早产指征的剖宫产分娩中，早产与呼吸窘迫的高风险相关。需要制定考虑早产不良影响的早产指南。
