Wilding Sam, Ziauddeen Nida, Roderick Paul, Smith Dianna, Chase Debbie, Macklon Nick, McGrath Nuala, Hanson Mark, Alwan Nisreen A
School of Primary Care and Population Sciences, Faculty of Medicine, University of Southampton, Southampton, UK.
Geography & Environment, University of Southampton, Southampton, UK.
BMJ Open. 2019 Jul 29;9(7):e026998. doi: 10.1136/bmjopen-2018-026998.
To investigate socioeconomic inequalities, using maternal educational attainment, maternal and partner employment status, and lone motherhood indicators, in the risk of small-for-gestational-age (SGA) births, their time trend, potential mediation by maternal smoking and body mass index, and effect modification by parity.
Population-based birth cohort using routine antenatal healthcare data.
Babies born at University Hospital Southampton, UK, between 2004 and 2016.
65 909 singleton live births born to mothers aged ≥18 years between 24-week and 42-week gestation.
SGA (birth weight <10th percentile for others born at the same number of completed weeks compared with 2013/2014 within England and Wales).
Babies born to mothers educated up to secondary school level (adjusted OR (aOR) 1.32, 99% CI 1.19 to 1.47), who were unemployed (aOR 1.27, 99% CI 1.16 to 1.38) or with unemployed partners (aOR 1.27, 99% CI 1.13 to 1.43), were at greater risk of being SGA. There was no statistically significant change in the magnitude of this risk difference by these indicators over time between 2004 and 2016, as estimated by linear interactions with year of birth. Babies born to lone mothers were not at higher risk compared with partnered mothers after adjusting for maternal smoking (aOR 1.05, 99% CI 0.93 to 1.20). The inverse association between maternal educational attainment and SGA risk appeared greater in multiparous (aOR 1.40, 99% CI 1.10 to 1.77) compared with primiparous women (aOR 1.28, 99% CI 1.12 to 1.47), and the reverse was true for maternal and partner's unemployment where the association was stronger in primiparous women.
Socioeconomic inequalities in SGA risk by educational attainment and employment status are not narrowing over time, with differences in association strength by parity. The greater SGA risk in lone mothers was potentially explained by maternal smoking. Preventive interventions should target socially disadvantaged women, including preconception and postpartum smoking cessation to reduce SGA risk.
利用母亲教育程度、母亲及伴侣就业状况和单亲母亲身份指标，调查小于胎龄儿（SGA）出生风险中的社会经济不平等现象、其时间趋势、母亲吸烟和体重指数的潜在中介作用以及胎次的效应修正。
基于人群的出生队列研究，使用常规产前保健数据。
英国南安普敦大学医院2004年至2016年间出生的婴儿。
65909例单胎活产，母亲年龄≥18岁，孕周在24周和42周之间。
小于胎龄儿（出生体重低于英格兰和威尔士2013/2014年同孕周出生婴儿的第10百分位数）。
母亲受教育程度为中学及以下（校正比值比（aOR）1.32，99%可信区间1.19至1.47）、失业（aOR 1.27，99%可信区间1.16至1.38）或伴侣失业（aOR 1.27，99%可信区间1.13至1.43）的婴儿患小于胎龄儿的风险更高。根据与出生年份的线性交互作用估计，2004年至2016年间，这些指标导致的风险差异大小没有统计学上的显著变化。在调整母亲吸烟因素后，单亲母亲所生婴儿与有伴侣母亲所生婴儿相比，风险并未更高（aOR 1.05，99%可信区间0.93至1.20）。与初产妇（aOR 1.28，99%可信区间1.12至1.47）相比，经产妇中母亲教育程度与小于胎龄儿风险之间的负相关似乎更强（aOR 1.40，99%可信区间1.10至1.77），而母亲及伴侣失业情况则相反，初产妇中的相关性更强。
按教育程度和就业状况划分的小于胎龄儿风险中的社会经济不平等现象并未随时间推移而缩小，且在胎次方面存在关联强度差异。单亲母亲中较高的小于胎龄儿风险可能由母亲吸烟所致。预防性干预措施应针对社会经济地位不利的女性，包括孕前和产后戒烟，以降低小于胎龄儿风险。
