School of Public Health, Xi'an Jiaotong University, Xi'an, 710061, China.
Xi'an Maternal and Child Healthcare Hospital, Xi'an, China.
BMC Public Health. 2024 Jul 15;24(1):1886. doi: 10.1186/s12889-024-19445-2.
The modifiable mechanisms underlying the association between socioeconomic status (SES) and preterm birth remain unclear. This study aimed to investigate the relationship between preterm birth and maternal SES or gestational weight gain (GWG), as well as the role of GWG in mediating SES disparities in preterm birth.
Data was from a hospital-based sub-study of physical growth and development survey for Chinese newborns with various gestational ages. Singleton newborns aged from 24 to 42weeks' gestation and their mothers were included. Using information from maternal questionnaire, a composite SES was constructed with parental education and family annual income. GWG as mediator was calculated by deducting pre-pregnancy weight from maternal weight at delivery. Logistic regression model was adopted to investigate the association of preterm birth with SES or GWG. Causal mediation analysis was performed to measure mediating effect of GWG on the pathway from SES to preterm birth.
After controlling for potential confounders, risk of preterm birth was reduced by 12.4% (OR = 0.876, 95%CI:0.855-0.879) for per one-kilogram increase of GWG, and risk of preterm birth was reduced by 24% (OR = 0.760, 95%CI: 0.717-0.806) for per one-unit increase of SES score. Mediation analysis supported a significant association between higher SES and decreased risk of preterm partly through higher GWG, in which estimated proportion mediated by GWG was 13.04% (95%CI: 11.89-16.25). GWG also played a significant role as a mediator when socioeconomic status was indicated by maternal education, paternal education or family income. GWG mediated approximately 11.03% (95% CI: 8.56-18.25) of the total effect of SES on very preterm birth, which was greater than that for moderate preterm birth (6.72%, 95%CI: 2.72-31.52) and late preterm birth (9.04%, 95%CI: 5.24-24.04). A series of sensitive analysis confirmed the robustness of association of interest.
Increased GWG and higher socioeconomic status are strongly associated with a lower risk of preterm birth. GWG mediates socioeconomic disparities in preterm birth, most notably in very preterm birth. Understanding this mechanism will aid in the development of interventions and policy for maternal and child health care.
社会经济地位（SES）与早产之间关联的可改变机制仍不清楚。本研究旨在探讨早产与产妇 SES 或妊娠体重增加（GWG）之间的关系，以及 GWG 在介导 SES 与早产差异方面的作用。
数据来自中国新生儿不同胎龄体格生长发育调查的基于医院的子研究。纳入胎龄 24 至 42 周的单胎新生儿及其母亲。使用来自产妇问卷的信息，构建了由父母教育和家庭年收入组成的综合 SES。GWG 作为中介，通过从母亲分娩时的体重中减去孕前体重来计算。采用 logistic 回归模型探讨早产与 SES 或 GWG 的关系。进行因果中介分析以衡量 GWG 在 SES 至早产的途径上的中介效应。
在控制了潜在混杂因素后，GWG 每增加 1 公斤，早产风险降低 12.4%（OR=0.876，95%CI：0.855-0.879），SES 评分每增加 1 个单位，早产风险降低 24%（OR=0.760，95%CI：0.717-0.806）。中介分析支持 SES 较高与 GWG 较高导致早产风险降低之间存在关联，其中 GWG 介导的比例为 13.04%（95%CI：11.89-16.25）。当 SES 由母亲教育、父亲教育或家庭收入表示时，GWG 也作为一个重要的中介发挥作用。GWG 介导 SES 对极早产的总效应的 11.03%（95%CI：8.56-18.25），大于对中度早产（6.72%，95%CI：2.72-31.52）和晚期早产（9.04%，95%CI：5.24-24.04）。一系列敏感性分析证实了所关注关联的稳健性。
GWG 增加和 SES 升高与早产风险降低密切相关。GWG 介导 SES 与早产之间的差异，在极早产中最为明显。了解这一机制将有助于制定母婴保健干预措施和政策。
