Microplastics in Female Reproductive and Pregnancy Organs: A Systematic Review.

Background: Microplastics (MPs) have rapidly emerged as pervasive environmental contaminants with growing implications for human health. Evidence now shows that MP exposure may begin during pregnancy and extend into infancy. Foetal exposure to MP raises questions about MP presence within reproductive organs, maternal-foetal MP transfer and the potential impact of MP on women's reproductive health. Objectives: To synthesise current evidence on the presence and distribution of microplastics in the female reproductive system and pregnancy-related organs. Methods: A systematic review of literature was conducted using Embase and Medline databases, supplemented by reference screening and manual searches. Studies were eligible if they examined MP in human female reproductive organs or pregnancy-related tissues and were published in English. Results: Eleven studies met the inclusion criteria. Across studies, MP detection varied substantially due to differences in sampling protocols, analytical techniques, and particle size detection thresholds. Cross-contamination and analytical method variability remained major methodological concerns. MP were consistently identified in follicular fluid, placental tissue, amniotic fluid, cord blood, and meconium. Conclusions: The presence of MP in both maternal and foetal compartments supports the possibility of in utero maternal-foetal MP transfer. A standardised protocol should be used to assess MP presence and MP's impact on organs and tissues. The current variability of diagnostic tests, the lack of cofounding variables control and the reduced sample sizes limit the ability to determine how clinically relevant MP exposure is during pregnancy and to women's reproductive health.