Association of human leukocyte antigen-G 14 bp polymorphism with recurrent pregnancy loss in European countries: a meta-analysis of literature studies

To study the controversial association between human leukocyte antigen-G (HLA-G) 14 bp polymorphism and recurrent pregnancy loss (RPL). We performed a meta-analysis of studies in the literature that enrolled only women of European countries who experienced RPL spontaneously or after undergoing IVF. Systematic meta-analysis of articles published before January 2019 pertaining the association of HLA-G genotype and RPL. The search was performed in electronic databases (PubMed, Web of Science, Scopus, EMBASE), without any language or publication year restriction. Academic hospitals and private clinics. Women who experienced RPL spontaneously or after undergoing IVF. Genotyping of 14 bp polymorphism (insertion/insertion, insertion/deletion, deletion/deletion) in exon 8 of the HLA-G gene. Meta-analyses of the association between HLA-G 14 bp polymorphism in homozygosis (insertion/insertion) and heterozygosis (insertion/deletion) in women with RPL compared with pregnant controls with at least one live birth and no history of RPL. Ten studies were analyzed comprising 1,091 women with RPL and 808 controls without RPL. Women with RPL showed significantly higher prevalence of HLA-G 14 bp insertion/insertion genotype compared with women without RPL (19.8% vs. 14.1%; odds ratio = 1.562; 95% confidence interval, 1.203–2.027), and this result was also confirmed when separately analyzing women with RPL during a spontaneous pregnancy (odds ratio, 1.562; 95% confidence interval, 1.203–2.027) and those undergoing IVF (odds ratio, 1.990; 95% confidence interval, 0.978–4.051). Women of European countries with the HLA-G 14 bp insertion/insertion genotype have a significantly higher prevalence of RPL. Asociación del polimorfismo de leucocitos humanos de antígeno-G de 14 pb con la pérdida recurrente de embarazo en países europeos: metaanálisis de estudios de la literatura estudiar la controvertida asociación entre el polimorfismo de 14 pb del antígeno leucocitario humano (HLA-G) y la pérdida de embarazo recurrente (RPL). Realizamos un metaanálisis de estudios de la literatura que incluyeron sólo mujeres de países europeos que experimentaron RPL espontáneamente o después de someterse a FIV. metaanálisis sistemático de artículos publicados antes de enero de 2019 relacionados con la asociación del genotipo HLA-G y RPL. La búsqueda se realizó en bases de datos electrónicas (PubMed, Web of Science, Scopus, EMBASE), sin ninguna restricción con respecto a idioma o año de publicación. Hos