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BACKGROUND: Experimental studies have shown that disinfection byproducts (DBPs) including haloacetic acids (HAAs) can cause liver toxicity, but evidence linking this association in humans is sparse. OBJECTIVES: We aimed to explore the associations between HAA exposures and liver injury. METHODS: We included 922 women between December 2018 and January 2020 from the Tongji Reproductive and Environmental (TREE) cohort study in Wuhan, China. Urinary HAA concentrations including trichloroacetic acid (TCAA) and dichloroacetic acid (DCAA) and serum indicators of liver function, including alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyltransferase (GGT) were measured. Liver injury was defined as if any of serum indicator levels were above the 90th percentile. Multivariate logistic and linear regression models were fitted to assess the associations of urinary HAA concentrations with the risk of liver injury and liver function indicators. Stratified analyses by age, body mass index (BMI), alcohol use, and passive smoking were also applied to evaluate the potential effect modifiers. RESULTS: There is little evidence of associations of urinary TCAA concentrations with liver injury risk and liver function indicators. However, urinary DCAA concentrations were associated with a higher risk of liver injury [odds ratios (OR) for 1-interquartile range (IQR) increase in natural log (ln) transformed DCAA concentrations: 1.45; 95% confidence interval (CI): 1.07, 1.98]. This association was observed only among nondrinkers (푝interaction =0.058). We also found that a 1-IQR increase in ln-transformed DCAA concentrations was positively associated with ALT levels (percentage change =6.06%; 95% CI: 0.48%, 11.95%) and negatively associated with AST/ALT (percentage change= -4.48%; 95% CI: -7.80%, -1.04%). In addition, urinary DCAA concentrations in relation to higher GGT levels was observed only among passive smokers (푝interaction =0.040). CONCLUSION: Our findings suggest that exposure to DCAA but not TCAA is associated with liver injury among women undergoing assisted reproductive technology. [ABSTRACT FROM AUTHOR]

BACKGROUND: Phthalates have been reported to impair fertility in various studies. However, evidence exploring the associations between phthalate metabolites in follicular fluid (FF) and reproductive outcomes is lacking. OBJECTIVES: To investigate the associations between phthalate metabolite concentrations in FF and in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) outcomes among women recruited from a fertility clinic. METHODS: We included 641 women undergoing IVF/ICSI treatment from December 2018 to January 2020. The levels of eight phthalate metabolites, including monoethyl phthalate (MEP), mono-isobutyl phthalate (MiBP), mono-푛-butyl phthalate (MBP), monobenzyl phthalate (MBzP), mono(2- ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), and mono(2- ethyl-5-carboxypentyl) phthalate (MECPP), were quantified in FF collected on the oocyte retrieval day. Associations between quartiles of individual phthalate metabolite concentrations and nine IVF/ICSI outcomes, including oocyte yield, mature oocyte number, two distinct pronuclei (2PN) zygote number, fertilization rate, blastocyst formation rate, implantation, clinical pregnancy, miscarriage, and live birth, were estimated with generalized linear models. The effects of phthalate mixtures on IVF/ICSI outcomes were assessed using Bayesian kernel machine regression (BKMR) models. RESULTS: After adjusting for relevant confounders, elevated quartiles of MBzP, MEHHP, and MEHP in FF were inversely associated with the numbers of retrieved oocytes, mature oocytes, and 2PN zygotes (all 푝 for trends <0.10). In comparison with the lowest quartile, the highest quartile of molar sum of di(2-ethylhexyl) phthalate metabolites (RDEHP) was associated with a reduction of 9.1% [95% confidence interval (CI): –17:1%, –0:37%] and 10.3% (95% CI: –18:8%, –0:94%) in yielded oocyte and mature oocyte numbers, respectively. Furthermore, the BKMR models revealed inverse associations between phthalate mixtures and the numbers of retrieved oocytes and mature oocytes. We generally found null results for implantation, clinical pregnancy, miscarriage, and live birth. DISCUSSION: Certain phthalate metabolites in FF are inversely associated with the numbers of retrieved oocytes, mature oocytes, and 2PN zygotes among women undergoing IVF/ICSI treatment. [ABSTRACT FROM AUTHOR]

BACKGROUND: Experimental studies show that disinfection byproducts (DBPs) can inhibit oocyte maturation, decrease fertilization capacity, and impair embryo development, but human evidence is lacking. OBJECTIVES: We aimed to evaluate the associations between exposure to drinking water DBPs and in vitro fertilization (IVF) outcomes. METHODS: The study included 1,048 women undergoing assisted reproductive technology (ART) treatment between December 2018 and January 2020 from a prospective cohort study, the Tongji Reproductive and Environmental study in Wuhan, China. Exposure to DBPs was assessed by dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) in up to four urine samples, which were collected on the day of both enrollment and oocyte retrieval. Multivariable generalized linear mixed models, accounting for multiple IVF cycles per woman, were applied to evaluate the associations between urinary biomarkers of DBP exposures and IVF outcomes. Stratified analyses were used to explore the potential effect modifiers. RESULTS: The included 1,048 women underwent 1,136 IVF cycles, with 960 (91.6%), 84 (8.0%), and 4 (0.4%) women contributing one cycle, two cycles, and three cycles, respectively. We found that elevated quartiles of urinary DCAA and TCAA concentrations were associated with reduced numbers of total oocytes and metaphase II oocytes and that urinary DCAA concentrations with a lower proportion of best-quality embryos (all 푝 for trends<0.05). Moreover, elevated quartiles of urinary DCAA concentrations were associated with decreased proportions of successful implantation, clinical pregnancy, and live birth (14%, 15%, and 15% decreases in adjusted means comparing the extreme quartiles, respectively; all 푝 for trends<0.05). Stratification analyses showed that the inverse associations of urinary TCAA concentrations with multiple IVF outcomes were stronger among women ≥30 y of age (푝 for interactions<0.05). DISCUSSION: Exposure to drinking water DBPs was inversely associated with some IVF outcomes among women undergoing ART treatment. Further study is necessary to confirm our findings. [ABSTRACT FROM AUTHOR]