Association between exposure of light rare earth elements and outcomes of in vitro fertilization-embryo transfer in North China

• Published in: The Science of the total environment 2021-03, Vol.762, p.143106-143106, Article 143106
• Main Authors: Li, Mengshi, Zhuang, Lili, Zhang, Guohuan, Lan, Changxin, Yan, Lailai, Liang, Rong, Hao, Cuifang, Li, Zhiwen, Zhang, Jingxu, Lu, Qun, Wang, Bin
• Format: Article
• Language: English
• Subjects: China - epidemiology; Cities; Embryo Transfer; Female; Fertilization in Vitro; Humans; In vitro fertilization and embryo transfer; Lanthanum; Metals, Rare Earth - analysis; Pregnancy; Rare earth elements; Reproductive toxicity; Spontaneous abortion
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2020.143106

The adverse health effects of rare earth elements (REEs) on reproductive health remain a subject of debate, and few clinical observations are available. This study investigated the association between light REEs (LREEs) exposure and the outcome of in vitro fertilization–embryo transfer (IVF-ET). We recruited a total of 305 women undergoing IVF-ET in Beijing City and Shandong Province of northern China. Their demographic information and lifestyle characteristics were collected using questionnaires at enrollment. Fasting blood samples were collected on the day before the IVF-ET treatment cycle began. Serum concentrations of the LREEs of concern were analyzed using inductively coupled plasma-mass spectrometry, and four LREEs were measured with a high detection rate, including lanthanum (La), cerium (Ce), praseodymium (Pr), and neodymium (Nd). We found that a higher serum La concentration was associated with a 30% increased likelihood of clinical pregnancy failure [relative risk (RR) = 1.30, 95% confidence interval (CI): 1.00–1.67] and a 230% increased likelihood of preclinical spontaneous abortion (RR = 3.30, 95% CI: 1.57–6.94). There was a negative correlation between serum La concentration and the number of good-quality oocytes. For the other LREEs, no statistically significant associations were observed. We concluded that a high serum La concentration may have an adverse effect on IVF-ET outcomes. [Display omitted] •Adverse effects of rare earth elements (REEs) on reproductive health remain unclear.•A total of 305 women undergoing IVF-ET were recruited in northern China.•High serum La was associated with 30% increased risk of clinical pregnancy failure.•Serum La was negatively correlated with the number of good-quality oocytes.•A high serum La concentration may have an adverse effect on IVF-ET outcomes.