Abstract:

Recurrent spontaneous abortion (RSA) is defined as three or more consecutive abortions before 20 weeks of gestation. Cytokines are proteins or small molecular peptides for cell signaling, immune regulation and response, which affect all stages of pregnancy and play a vital role in pregnancy outcome. Because cytokines are very important in maternal-fetal immune regulation and genetic polymorphisms have potential impact on function and expression of cytokines, the association between cytokine genetic polymorphisms and RSA has become a hot topic of international research recently. There are some problems in reported studies. For example, the results of different studies are inconsistent or even conflicting, therefore it is difficult to determine the role of cytokine polymorphisms in RSA; most studies reported several positive cases and lack verification from other populations, thus the false positive risk may exist; the sample size of case-control studies was small (<400) with low statistical power, resulting in false negative findings; tagging single-nucleotide polymorphisms (SNPs) were not fully studied, thus the causal variants may be missed; the impact of gene-gene interaction and gene-environment interaction on RSA was not investigated. Therefore, increasing the sample size, systematically studying representative genetic polymorphisms, and exploring the impact of gene-gene and gene-environment interaction on RSA become an urgent need in this field.

Key words: recurrent spontaneous abortion, cytokine, single-nucleotide polymorphism