Fukushima Regional Center for the Japan Environmental and Children's Study.
Department of Obstetrics and Gynecology, School of Medicine, Fukushima Medical University.
J Epidemiol. 2019 May 5;29(5):187-191. doi: 10.2188/jea.JE20170283. Epub 2018 Aug 4.
In Japan, mean maternal age at first childbirth is increasing. The aim of this study was to investigate whether maternal age at the first childbirth is a risk factor for preterm birth (PTB), low birth weight (LBW), and small for gestational age (SGA).
We used the results of Japan Environment and Children's Study (JECS) who gave birth in 2011-2014. Cases of primiparous singleton pregnancies where the subject was ≥20 years and delivered after 22 weeks were included. All subjects were categorized into five groups according to maternal age: 20-24, 25-29, 30-34, 35-39, and ≥40 years. Adjusted odds ratios (aORs) for PTB (before 37 and 34 weeks), LBW (<2,500 g and <1,500 g), and SGA were calculated using a logistic regression model, with the 20-24-year age group as reference.
We analyzed 38,412 singleton primiparous pregnancies. The aORs of all outcomes increased in parallel with each maternal age group >30 years. The aORs of PTB before 37 and 34 weeks, LBW <2,500 g, LBW <1,500 g, and SGA in the 30-34-year age group were 1.39 (95% confidence interval [CI], 1.16-1.67), 2.23 (95% CI, 1.45-3.41), 1.34 (95% CI, 1.18-1.53), 2.30 (95% CI, 1.35-3.94), and 1.24 (95% CI, 1.05-1.46), respectively.
The present study showed that higher maternal age (>30 years) at the first childbirth was an independent risk factor for PTB, LBW, and SGA.
在日本，初产妇的平均年龄正在增加。本研究旨在探讨初产妇年龄是否是早产（PTB）、低出生体重（LBW）和小于胎龄儿（SGA）的危险因素。
我们使用了 2011-2014 年日本环境与儿童研究（JECS）的结果。纳入的病例为初产妇单胎妊娠，母亲年龄≥20 岁，分娩孕周≥22 周。所有受试者按母亲年龄分为五组：20-24 岁、25-29 岁、30-34 岁、35-39 岁和≥40 岁。采用 logistic 回归模型计算 PTB（<37 周和<34 周）、LBW（<2500g 和<1500g）和 SGA 的调整优势比（aOR），以 20-24 岁年龄组为参照。
我们分析了 38412 例单胎初产妇妊娠。所有结局的 aOR 均随母亲年龄>30 岁的每个年龄组平行增加。30-34 岁年龄组的 PTB<37 周和<34 周、LBW<2500g、LBW<1500g 和 SGA 的 aOR 分别为 1.39（95%可信区间[CI]，1.16-1.67）、2.23（95%CI，1.45-3.41）、1.34（95%CI，1.18-1.53）、2.30（95%CI，1.35-3.94）和 1.24（95%CI，1.05-1.46）。
本研究表明，初产妇年龄较高（>30 岁）是 PTB、LBW 和 SGA 的独立危险因素。
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