Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China; Department of Epidemiology and Health Statistics, Xiangya School of Public Health, Central South University, Changsha, Hunan, China.
Department of Environmental Health Sciences, University at Albany State University of New York, One University Place, Rensselaer, Albany, NY, USA; Department of Epidemiology and Biostatistics, University at Albany State University of New York, One University Place, Rensselaer, Albany, NY, USA.
Prev Med. 2021 Feb;143:106319. doi: 10.1016/j.ypmed.2020.106319. Epub 2020 Nov 7.
Low maternal socioeconomic status (SES) is considered as a risk factor of congenital heart diseases (CHDs) in offspring. However, the pathways underpinning the SES-CHDs associations are unclear. We assessed if first trimester maternal folic acid supplementation (FAS) is a mediator of the SES-CHDs associations. This case-control study included 8379 CHD cases and 6918 CHD-free controls from 40 participating centers in Guangdong, Southern China, 2004-2016. All fetuses were screened for CHDs using ultrasound and cases were confirmed by echocardiogram. We collected SES and FAS information during face-to-face interview by obstetricians using a structured questionnaire. Low SES was defined as education attainment <12 years, household individual income <3000 Chinese Yuan/person/month or unemployment. FAS referred to at least 0.4 mg of daily folic acid intake over 5 days/week continuously. We used causal mediation analysis to estimate the direct, indirect and proportion mediated by FAS on the SES-CHDs associations adjusted for confounders. Both low maternal income and education were significantly associated with increased risks of CHDs and lower prevalence of FAS. Low maternal FAS prevalence mediated 10% [95%CI:5%,13%] and 3% [95%CI:1%,5%] of the maternal low income-CHDs and the maternal low education-CHDs associations, respectively. In addition, FAS mediated the highest proportion of the associations between income and multiple critical CHDs [46.9%, 95%CI:24.7%,77%] and conotruncal defects [31.5%, 95%CI:17.1%,52.0%], respectively. Maternal FAS partially mediated the SES-CHDs associations, especially among the most critical and common CHDs. Promoting FAS in low SES women of childbearing age may be a feasible intervention to help prevent CHDs.
低孕产妇社会经济地位（SES）被认为是后代先天性心脏病（CHD）的危险因素。然而，SES-CHD 关联的潜在途径尚不清楚。我们评估了孕妇在妊娠早期补充叶酸（FAS）是否是 SES-CHD 关联的一个中介因素。这项病例对照研究包括 2004 年至 2016 年期间，来自中国南方广东省 40 个参与中心的 8379 例 CHD 病例和 6918 例无 CHD 对照。所有胎儿均通过超声筛查 CHD，病例通过超声心动图确诊。我们通过妇产科医生使用结构化问卷进行面对面访谈收集 SES 和 FAS 信息。低 SES 定义为受教育程度<12 年，家庭人均收入<3000 元/人/月或失业。FAS 是指每周至少连续 5 天每天摄入 0.4 毫克叶酸。我们使用因果中介分析来估计 FAS 对 SES-CHD 关联的直接、间接和中介作用，调整混杂因素。母亲收入低和受教育程度低均与 CHD 风险增加和 FAS 发生率降低显著相关。低母亲 FAS 发生率分别介导了母亲低收入-CHD 和母亲低教育-CHD 关联的 10%[95%CI：5%，13%]和 3%[95%CI：1%，5%]。此外，FAS 介导了收入与多种严重 CHD[46.9%，95%CI：24.7%，77%]和圆锥动脉干缺陷[31.5%，95%CI：17.1%，52.0%]之间关联的最大比例。FAS 部分介导了 SES-CHD 关联，尤其是在最严重和最常见的 CHD 中。在低 SES 的育龄妇女中推广 FAS 可能是一种可行的干预措施，有助于预防 CHD。
