Association between microplastics in human amniotic fluid and pregnancy outcomes: Detection and characterization using Raman spectroscopy and pyrolysis GC/MS

Microplastic contamination has emerged as a global environmental concern, while the limitation of single-technique identification methods in complex biological matrices calls for multi-analytical approaches for accurate microplastic detection. This study pioneers a dual-method approach, combining Raman spectroscopy and pyrolysis gas chromatography-mass spectrometry (Py-GC/MS), to investigate microplastics in human amniotic fluid. In total, samples from 48 pregnant women were collected and analyzed under stringent quality control measures, then Raman spectroscopy and Py-GC/MS were employed for comprehensive polymer identification and verification. Our analysis revealed 6 distinct microplastic polymer types in 39 subjects, with an average particle size of 3.05 ± 1.05 µm, polytetrafluoroethylene (PTFE, 31.25 %), polystyrene (PS, 20.83 %), and acrylonitrile-butadiene-styrene (ABS, 14.58 %) being the most prevalent. Py-GC/MS analysis corroborated the Raman spectroscopy findings, identifying pyrolytic markers such as fluoroethylene for PTFE and styrene for PS. However, no significant associations were found between microplastic exposure and immediate adverse pregnancy outcomes. This study, for the first time, utilizes a dual-method approach combining Raman spectroscopy and Py-GC/MS to conclusively demonstrate the presence of diverse microplastics in human amniotic fluid, which underscores the need for larger-scale, longitudinal investigations to elucidate the potential long-term health implications of microplastic exposure.