Supplementary file 1_Occupational exposure to inhalational anesthetics and the risk of spontaneous abortion: a systematic review and meta-analysis.docx

BackgroundHealthcare professionals, particularly anesthesiologists, nurses, and dental staff, are routinely exposed to inhalational anesthetic agents such as nitrous oxide and halogenated gases. Although scavenging and ventilation systems have reduced ambient levels, concerns remain regarding reproductive risks associated with chronic exposure. Previous studies have yielded inconsistent results. A systematic review and meta-analysis of published observational studies was conducted to clarify the relationship, assessing reproductive outcomes among healthcare workers who were exposed.
ObjectiveThis systematic review and meta-analysis aimed to clarify the association between occupational exposure to anesthetic gases and the risk of spontaneous abortion among healthcare workers.
MethodsA systematic search was performed in PubMed, Scopus, and Web of Science up from inception until the end of July 2025. Observational studies assessing spontaneous abortion among female healthcare workers exposed to inhalational anesthetics were included. Two reviewers independently screened and extracted data and assessed study quality using the Newcastle–Ottawa Scale (NOS). Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using a random-effects model. Heterogeneity was evaluated using the I2 statistic, and potential moderators were explored via subgroup and meta-regression analyses.
ResultsSeventeen studies were included. The pooled analysis showed 1.29-fold higher odds of spontaneous abortion among exposed workers compared with unexposed controls (OR = 1.29; 95% CI: 0.96–1.75; I2 = 87%). Subgroup analyses indicated stronger associations in North American studies and among high-exposure occupations. Meta-regression analysis indicated that exposure duration is a significant predictor (p = 0.010), accounting for 73.6% of the heterogeneity. Sensitivity and Egger’s tests revealed robust findings without evidence of publication bias.
ConclusionOccupational exposure to anesthetic gases may increase the risk of spontaneous abortion, particularly in those who are at high exposure, emphasizing the need for stringent exposure control and improved workplace safety standards.