Couples’ preconception urinary essential trace elements concentration and spontaneous abortion risk: A nested case-control study in a community population

Background: Previous studies have indicated a correlation between maternal imbalances in essential trace elements during pregnancy and the occurrence of spontaneous abortion (SA). Nonetheless, the impact of these elements from both partners and during the preconception period remains unexplored. Objective: This study sought to evaluate the relationship between preconception essential trace elements and spontaneous abortion (SA) based on husband–wife dyads. Methods: This study selected 390 couples with spontaneous abortion (SA) and 390 matched couples with live births from a preconception cohort of 33,687 couples. Urine samples collected prior to pregnancy were analyzed for ten essential trace elements (Se, Cr, Mo, Cu, Zn, Fe, Mn, V, Co, and Ni) using inductively coupled plasma mass spectrometry (ICP-MS). Results: Multivariate conditional logistic regression analysis identified that elevated concentrations of Zn (OR = 0.73) and Ni (OR = 0.69) in couples were associated with a reduced risk of SA, whereas elevated levels of Cr (OR = 1.30) and Mn (OR = 1.39) were linked to an increased risk. Restricted cubic spline models suggested a U-shaped association between couples’ Cu and Co concentrations and SA. Bayesian Kernel Machine Regression further supported a U-shaped relationship between the mixture of ten elements and SA, showing significant protection at the 50th and 55th percentiles compared to the 10th percentile. Additionally, the effects of Cr, Zn, Mn, and Ni on SA varied when the concentrations of the other nine elements were held constant at their 25th, 50th, and 75th percentiles. Stratified analysis revealed that maternal Cu (OR = 0.43) and Fe (OR = 0.63) reduced the risk of SA when paternal Cu and Fe were in the lower quartile. Conversely, maternal Cu (OR = 2.03) and Fe (OR = 1.77) increased the risk of SA when paternal concentrations were in the higher quartile. Similar patterns were observed for Cr, Mn, Co, and Zn. Conclusion: Elevated urinary concentrations of Zn and Ni in couples were associated with a reduced risk of SA, while higher levels of Cr and Mn were linked to an increased risk. Cu, Co, and a mixture of ten essential trace elements exhibited a U-shaped relationship with SA. The impact of certain essential trace elements (Cu, Fe, Cr, Mn, Co, and Zn) on SA in one partner was influenced by their concentrations in the other partner.