Non-genetic risk factors of miscarriage: a comprehensive umbrella review of systematic review and meta-analysis
Year: 2025
Type: review
Abstract: Numerous systematic reviews have examined the non-genetic factors associated with the risk of miscarriage. Therefore, this study aimed to conduct an umbrella review on non-genetic factors associated with the risk of miscarriage. Scopus, PubMed, Embase, and Web of Science were searched until 2025 and the systematic review and meta-analysis articles that were conducted on observational studies were extracted. Quality assessment of the selected review articles was done by AMSTAR. For each selected meta-analysis, the summary effect size with the 95% confidence interval was estimated using the random-effects model and the predictive interval (PI) at 95% was estimated too. The between-study heterogeneity was assessed by the I 2 index. In addition, two biases, including small-study effects and excess statistical significance, were investigated. Finally, 147 meta-analyses and 29 systematic review studies remained. None of the factors met all the necessary criteria and showed a definite association. However, 45 factors were classified as associations supported by suggestive evidence. Among these 45 factors, three factors—hypothyroidism, high serum β-human chorionic gonadotropin, and hairdressers—included the most complete information (they had more than 1,000 cases, significant based on the random-effects model, p < 0.001, respectively; (2/01(1/66–2/44), 2/88(1/76–4/68), 1/28(1/11–1/47)). Only 45 non-genetic factors had statistically significant associations without bias and heterogeneity, but were classified in the associations supported by suggestive evidence group because the PI (95%) included the null value.
Source: Reproductive Health
Language: English
Subfield: Immunology
Field: Immunology and Microbiology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $3,290
OpenAlex ID: W4416594752