Okui Tasuku, Nakashima Naoki
Medical Information Center, Kyushu University Hospital, Fukuoka, Japan.
J Prev Med Public Health. 2024 Nov;57(6):564-571. doi: 10.3961/jpmph.24.355. Epub 2024 Sep 24.
Prior research has not yet examined the relationship between post-term birth and neonatal mortality in Japan, along with factors associated with post-term birth. We investigated these associations utilizing nationwide birth data from Japan.
Birth and mortality data were obtained from the Vital Statistics of Japan for the years 2017 to 2022. The post-term birth rate was calculated by birth characteristics, and the neonatal mortality rates for post-term and term births were computed. Additionally, log-binomial regression analysis was employed to explore the associations between post-term birth and neonatal mortality, as well as between various characteristics and post-term birth. The characteristics considered included infant sex, maternal age group, parity, maternal nationality, maternal marital status, and household occupation.
This study analyzed data from 4 698 905 singleton infants born at 37 weeks of gestational age or later. Regression analysis revealed that post-term birth was positively associated with neonatal mortality. The adjusted risk ratio for neonatal mortality in post-term compared to term births was 8.07 (95% confidence interval, 5.06 to 12.86). Factors positively associated with post-term birth included female infant sex, older maternal age, primiparity, non-Japanese maternal nationality, unmarried status, and various household occupations, including farmer, full-time worker at a smaller company, other type of worker, and unemployed. Younger maternal age was inversely associated with post-term birth.
In Japan, post-term birth represents a risk factor for neonatal mortality. Additionally, socio-demographic characteristics, such as maternal marital status, nationality, and parity were found to be predictors of post-term birth.
以往研究尚未探讨日本过期产与新生儿死亡率之间的关系以及与过期产相关的因素。我们利用日本全国范围的出生数据对这些关联进行了调查。
从日本生命统计数据中获取2017年至2022年的出生和死亡率数据。根据出生特征计算过期产率，并计算过期产和足月产的新生儿死亡率。此外，采用对数二项回归分析来探讨过期产与新生儿死亡率之间以及各种特征与过期产之间的关联。所考虑的特征包括婴儿性别、母亲年龄组、产次、母亲国籍、母亲婚姻状况和家庭职业。
本研究分析了4698905例孕周37周及以后出生的单胎婴儿的数据。回归分析显示，过期产与新生儿死亡率呈正相关。过期产儿与足月儿相比，新生儿死亡率的调整风险比为8.07（95%置信区间，5.06至12.86）。与过期产呈正相关的因素包括女婴性别、母亲年龄较大、初产、非日本籍母亲、未婚状态以及各种家庭职业，包括农民、小公司全职员工、其他类型工人和失业者。母亲年龄较小与过期产呈负相关。
在日本，过期产是新生儿死亡的一个危险因素。此外，社会人口学特征，如母亲婚姻状况、国籍和产次被发现是过期产的预测因素。
