title: Association between Serum TNF-α Levels and Recurrent Spontaneous Miscarriage: A Meta-analysis.
abstract: Most recurrent spontaneous miscarriages (RSMs) are attributed to 'unexplained' factors, the majority of which are immune factors. Furthermore, clinically, only a small number of RSM patients get early diagnosis by testing for antiphospholipid antibodies, whereas most of the patients, present no specific diagnostic indicators. We performed a meta-analysis of observational studies to detect the association between RSM and TNF-α levels. We searched PubMed, EMBase, ScienceDirect, Web of Science, and Chinese databases (including: Wanfang Data, CNKI, and VIP databases) for articles published up to 2014. Of the 151 initially identified studies, 11 case-control studies with 1371 patients were finally analyzed. Overall, baseline TNF-α levels were higher in patients than in controls. The standardized mean difference of the TNF-α levels of the patients was 2.82 units (95% confidence interval 1.57-4.06) and the overall effect z-score was 4.42 (P < 0.0001). The heterogeneity test revealed significant differences among individual studies (P = 0.000, I(2)  = 98.7%). Serum TNF-α levels were significantly increased in patients relative to those in controls. The heterogeneity could be attributed to the differences in the detection methods and sampling times used in the different studies.
authors.affiliation: Medical Scientific Research Center, Guangxi Medical University, Nanning, Guangxi, China.|Department of Microbiology and Microbial Engineering, School of Life Sciences, Fudan University, Shanghai, China.
authors.forename: Chengdong
authors.initials: C
authors.lastname: Zhang
authors.affiliation: First Clinical Academy, Guangxi Medical University, Nanning, Guangxi, China.
authors.forename: Xiaozhen
authors.initials: X
authors.lastname: Deng
authors.affiliation: Medical Scientific Research Center, Guangxi Medical University, Nanning, Guangxi, China.
authors.forename: Xuerong
authors.initials: X
authors.lastname: Zhang
authors.affiliation: First Clinical Academy, Guangxi Medical University, Nanning, Guangxi, China.
authors.forename: Zhengyan
authors.initials: Z
authors.lastname: Pan
authors.affiliation: First Clinical Academy, Guangxi Medical University, Nanning, Guangxi, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhao
authors.affiliation: Medical Scientific Research Center, Guangxi Medical University, Nanning, Guangxi, China.
authors.forename: Yuening
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Medical Scientific Research Center, Guangxi Medical University, Nanning, Guangxi, China.|Department of Pathophysiology, Guangxi Medical University, Nanning, Guangxi, China.
authors.forename: Jiatong
authors.initials: J
authors.lastname: Li
authors.affiliation: Medical Scientific Research Center, Guangxi Medical University, Nanning, Guangxi, China.|Department of Pathophysiology, Guangxi Medical University, Nanning, Guangxi, China.
authors.forename: Feifan
authors.initials: F
authors.lastname: Xiao
authors.affiliation: Department of Cell Biology & Genetic, School of Preclinical Medicine, Guangxi Medical University, Nanning, Guangxi, China.
authors.forename: Huayu
authors.initials: H
authors.lastname: Wu
authors.affiliation: Department of Nephrology, the 4th Affiliated Hospital, Guangxi Medical University, Liuzhou, China.
authors.forename: Hezhang
authors.initials: H
authors.lastname: Tan
authors.affiliation: Department of Gynaecology and Obstetrics, GuangDong Provincial Hospital of Chinese People's Armed Police Force, Guangzhou, China.
authors.forename: Peifen
authors.initials: P
authors.lastname: Guo
authors.affiliation: Medical Scientific Research Center, Guangxi Medical University, Nanning, Guangxi, China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Yang
mesh_terms: D000026:Abortion, Habitual / Q000097:blood* / Q000453:epidemiology; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D011247:Pregnancy; D014409:Tumor Necrosis Factor-alpha / Q000097:blood*
chemical_list: D014409:Tumor Necrosis Factor-alpha
keywords: Biomarker; TNF-α; meta-analysis; spontaneous abortion