Polyethylene andPolyvinyl Chloride Nanoplastics inHuman Follicular Fluid and Seminal Plasma: Impact on Fertilizationand Sperm Quality

Plastic pollution is a growing global issue, with nanoplastics (NPs) posing a greater threat than microplastics. Micro/nanoplastics have been detected in various human tissues and bodily fluids, but their impacts on human fertility remain unclear. We used pyrolysis gas chromatography–mass spectrometry (Py-GC/MS) with liquid extraction to detect NPs in the follicular fluid (FF) and seminal plasma (SP) of 51 couples undergoing in vitro fertilization (IVF) to investigate the impact of NPs on fertility. In our study, polyethylene (PE) and polyvinyl chloride (PVC) were the most frequently detected NPs. In FF, the average PE and PVC concentrations were 1.21 μg/g and 1.85 μg/g, respectively, whereas in SP, they were 3.02 μg/g and 2.67 μg/g, respectively. For NPs in FF, no significant association was detected between PE or PVC levels and the ovarian reserve, whereas IVF data indicated that higher PE concentrations in the T2 and T3 groups were associated with significantly lower fertilization rates than those in the low-concentration T1 group (p = 0.0003, p = 0.007, respectively), a trend similar to that observed for PVC (p = 0.009, p = 0.008, respectively). For the NPs in SP, the PVC concentration was associated with reduced sperm motility (p-trend = 0.044), whereas no significant difference was observed among the PE or PVC groups according to the IVF data. Neither maternal nor paternal levels of NPs were significantly associated with embryo implantation or clinical pregnancy. In conclusion, these results indicate that NPs are detectable in both FF and SP, with PE and PVC nanoparticles adversely affecting fertilization rates and sperm quality.