Objective: To explore the association of arsenic with unexplained recurrent spontaneous abortion (URSA). Methods: A case-control study was conducted to select URSA patients who were admitted to the Beijing Maternal and Child Health Care Hospital affiliated to Capital Medical University from April to October 2018 as a case group. Women who had a normal pregnancy in the Family Planning Department of the hospital but volunteered to have an abortion were selected as a control group. The case and control group were paired in a 1: 1 ratio. The inclusion criteria of the case group were patients with newly diagnosed recurrent spontaneous abortion who had clinically confirmed more than 2 spontaneous abortions and had 20 weeks prior to pregnancy, excluding patients with recurrent spontaneous abortion caused by abnormal blood coagulation (anti-phospholipid antibody positive), abnormal physiological anatomy (B-ultrasound), abnormal immune factors (anti-nuclear antibody positive, anti-cardiolipin antibody, etc.), genetic chromosomal abnormalities (karyotype analysis) and pathogenic microbial infection. The control group was matched according to the age of the case group (±3 years old) and the gestational age (±2 weeks) to exclude adverse pregnancy outcomes such as stillbirth, congenital malformation, premature delivery and low birth weight infants. A total of 192 subjects were included. Questionnaires were used to collect information of all subjects, and 12 ml of peripheral venous blood was collected to detect blood arsenic levels. Blood arsenic levels were divided into low concentration group (<1.00 μg/L), medium concentration group (1.00-1.50 μg/L) and high concentration group (>1.50 μg/L). The multivariate conditional logistic regression was performed to analyze the relationship between blood arsenic exposure and URSA and explore the influencing factors of blood Arsenic. Results: The geometric mean values of blood arsenic level in the cases group and control group were 1.68 (1.50-1.86) μg/L and 1.26 (1.17-1.37) μg/L, respectively. The blood arsenic level in the case group was significantly higher than that in the control group (P<0.05). The results of multivariate conditional logistic regression analysis showed that after adjusting for tobacco exposure during pregnancy, pre-pregnancy body mass index and the effects of residential decoration in past five years, the risk of URSA was higher in the high-concentration group compared with the low-concentration group (OR=2.56, 95%CI:1.06-6.24). Conclusion: Blood arsenic may increase the risk of URSA in women of childbearing age.
目的： 探讨砷与不明原因复发性自然流产（URSA）的关联。 方法： 采用病例对照研究方法，选择2018年4—10月在首都医科大学附属北京妇产医院就诊的URSA患者作为病例组，在该医院计划生育科就诊的正常妊娠但自愿做人工流产的妇女作为对照组，按照1∶1比例进行配对。病例组纳入标准为临床上确认2次以上自然流产且均发生妊娠20周之前的新发复发性流产患者，排除由凝血异常（抗磷脂抗体阳性）、生理解剖结构异常（B超检查）、自身免疫因素异常（抗核抗体阳性、抗磷脂抗体等）、遗传染色体异常（核型分析）、病原微生物感染等原因造成的复发性自然流产患者；对照组按病例组的年龄（±3岁）、孕周（±2周）进行匹配，排除既往死胎、先天畸形、早产和低出生体重婴儿等不良妊娠结局者。共纳入192例研究对象，病例组和对照组各96例。采用问卷调查方法收集研究对象信息，并采集外周静脉血12 ml，检测血砷水平。将血砷水平分为低浓度组（<1.00 μg/L）、中浓度组（1.00~1.50 μg/L）、高浓度组（>1.50 μg/L），采用多因素条件logistic回归分析血砷与URSA发病风险的关联。 结果： 病例组和对照组对象的血砷几何均值（95%CI）分别为1.68（1.50~1.86）和1.26（1.17~1.37）μg/L，病例组血砷水平高于对照组（P<0.05）。多因素条件logistic回归结果显示，调整了孕期烟草暴露、孕前体重指数及近5年住宅装修的影响后，与血砷低浓度组对象相比，高浓度组对象的URSA患病风险OR（95%CI）值为2.56（1.06~6.24）。 结论： 血砷可能会增加育龄女性URSA的发病风险。.
Keywords: Arsenic; Case-control study; Unexplained recurrent spontaneous abortion.