High-level toxic metal exposure has become rare in the recent years. Although, it has not known whether relatively lower exposure may adversely affect human reproductive system. Spontaneous abortion (SA) is a serious reproductive problem, which, in many cases, the cause(s) is not clearly understood. To assess the relationship between prenatal blood level of metals and SA risk, we compared blood concentration of some heavy metals in samples taken from mothers recruited in Tehran Environment and Neurodevelopmental Defects (TEND) study conducted on apparently healthy pregnant women in Tehran, Iran who subsequently experienced spontaneous abortion with mothers who their pregnancy ended to live births. During early gestation, 206 women were enrolled to the survey and followed up till fetal abortion or baby deliveries occur. Blood metal concentrations were measured using an inductively coupled plasma mass spectrometer. The mean blood levels of lead, antimony, and nickel were higher in SA than ongoing pregnancy; however, this difference was not statistically significant. When adjusted for covariates, the logistic regression analysis showed significant association between maternal age and the risk of SA in all models. Among toxic metals only antimony had a noticeable positive relation with the risk of SA (OR: 1.65, 95% CI:1.08–2.52, P value: 0.02). Pearson’s correlation coefficient showed significant (P < 0.05) positive correlations among prenatal blood metals levels, except for nickel. Although the present study failed to provide strong evidence for the effects of toxic metals on the occurrence of SA at the relatively low-levels, these metals should be avoided in women who plan pregnancy and/or during the early stages of gestation to prevent the chance of adverse effects.

近年来，高水平的有毒金属暴露已变得罕见。虽然，尚不清楚相对较低的暴露是否会对人类生殖系统产生不利影响。自然流产 (SA) 是一种严重的生殖问题，在许多情况下，其原因尚不清楚。为了评估产前血液中金属水平与 SA 风险之间的关系，我们比较了在德黑兰环境和神经发育缺陷 (TEND) 研究中对伊朗德黑兰明显健康的孕妇进行的母亲样本中一些重金属的血液浓度，这些孕妇随后与怀孕结束为活产的母亲一起经历过自然流产。在妊娠早期，206 名妇女参加了调查，并随访至胎儿流产或分娩。使用电感耦合等离子体质谱仪测量血液金属浓度。SA 中铅、锑和镍的平均血液水平高于持续妊娠；然而，这种差异在统计学上并不显着。当调整协变量时，逻辑回归分析显示所有模型中母亲年龄与 SA 风险之间存在显着关联。在有毒金属中，只有锑与 SA 风险显着正相关（OR：1.65，95% CI：1.08-2.52，逻辑回归分析显示，在所有模型中，母亲年龄与 SA 风险之间存在显着关联。在有毒金属中，只有锑与 SA 风险显着正相关（OR：1.65，95% CI：1.08-2.52，逻辑回归分析显示，在所有模型中，母亲年龄与 SA 风险之间存在显着关联。在有毒金属中，只有锑与 SA 风险显着正相关（OR：1.65，95% CI：1.08-2.52，P值：0.02）。Pearson 相关系数显示 ，除镍外，产前血液金属水平之间存在显着（ P < 0.05）正相关。尽管本研究未能提供强有力的证据证明有毒金属对相对较低水平的 SA 发生的影响，但在计划怀孕的妇女和/或妊娠早期应避免使用这些金属，以防止发生这种情况的机会的不利影响。