مقالات پذیرفته شده در نهمین کنگره بین المللی زیست پزشکی
Impact of Microplastics in Ovarian Follicular Fluid on Oocyte Quality and Early Embryo Development: A Systematic Review and Meta-analysis
Impact of Microplastics in Ovarian Follicular Fluid on Oocyte Quality and Early Embryo Development: A Systematic Review and Meta-analysis
Sana Mahdian Rizi,1,*
1. Affiliation: Students Research Committee, Neyshabur University of Medical Sciences, Neyshabur, Iran
Introduction: Microplastics are emerging environmental contaminants with endocrine-disrupting potential. Recent studies have reported microplastics in human ovarian follicular fluid, raising concerns about their direct impact on reproductive outcomes. This systematic review and meta-analysis synthesized available human evidence to examine associations between microplastic burden in follicular fluid and outcomes including oocyte quality, fertilization, and embryo development during assisted reproductive technologies (ART).
Methods: Following PRISMA 2020, we searched PubMed, EMBASE, Scopus, Web of Science, and Cochrane CENTRAL (January 2020–June 2025). Eligible studies quantitatively measured microplastics in follicular fluid and reported at least one reproductive outcome. Animal studies, reviews, and case series (n<5) were excluded. Two reviewers independently screened and extracted data. Study quality was appraised using the Newcastle-Ottawa Scale. Random-effects meta-analysis (DerSimonian-Laird) was conducted with R (v4.2, “meta”) and STATA 17. Outcomes were summarized as standardized mean differences (SMD) or odds ratios (OR) with 95% confidence intervals (CI). Heterogeneity was assessed with I², and publication bias with funnel plots and Egger’s test. Meta-regression examined moderators including particle size, polymer type, and exposure context.
Results: We included 12 human studies (n=345 women) undergoing IVF/ICSI. Follicular fluid microplastic concentrations ranged 0.3–18 µg/mL, primarily polypropylene, polyethylene, and polystyrene.
Oocyte quality: Higher microplastic levels (>median) were associated with poorer quality (SMD = –0.48; 95% CI: –0.75 to –0.21; p<0.001; I²=62%), including ~13% smaller mean oocyte diameter.
Fertilization rate: Women with higher exposure showed a 20% reduced chance of successful fertilization (OR = 0.80; 95% CI: 0.68–0.95; p=0.01).
Embryo development: Blastocyst formation declined significantly with high microplastic burden (>10 µg/mL), with a 25% reduction in high-quality blastocysts (SMD = –0.62; 95% CI: –0.95 to –0.30). Cleavage delays and abnormal fragmentation were also reported.
Meta-regression: Stronger adverse effects were linked to submicron particles (<1 µm), polypropylene polymers, and occupational versus environmental exposure (p<0.05).
Bias assessment: Funnel plot asymmetry indicated minor publication bias; sensitivity analysis confirmed robustness of findings.
Conclusion: This review provides the first pooled evidence that microplastics in ovarian follicular fluid are associated with impaired oocyte quality, reduced fertilization, and suboptimal embryo development. These findings highlight an urgent, under-recognized risk to female reproductive health with implications for ART success rates. Larger, high-quality studies with standardized microplastic detection are essential to confirm causality and uncover mechanisms, such as oxidative stress and inflammatory signaling. Reducing environmental microplastic exposure may represent a novel preventive strategy in reproductive medicine.