Polymorphisms of methalenetetrahydrofolate reductase in recurrent pregnancy loss: an overview of systematic reviews and meta-analyses.

Abstract

The aim is to summarize and evaluate current systematic reviews and meta-analyses on MTHFR polymorphisms in recurrent pregnancy loss (RPL). We searched Pubmed and Embase databases and selected in form of PICOS (participants, interventions, comparisons, outcomes, and study design). Our methodology was registered on PROSPERO (CRD42017042762). Systematic reviews and meta-analyses containing primary studies were extracted for meta-analyses, along with their OR and 95%CI. We assessed the quality of the included studies using AMSTAR and OQAQ criteria. Eleven systematic reviews and meta-analyses were identified. C677T was significantly related to RPL overall in Allele (OR, 95%CI 1.43, 1.29-1.60), Recessive (OR, 95%CI 1.66, 1.42-1.95), and Homozygous (OR, 95%CI 2.08, 1.66-2.61). There was no correlation observed between A1298C and RPL, except for in Heterozygous (OR, 95%CI 1.62, 1.17-2.25). We identified a difference in the association between MTHFR C677T polymorphism and RPL, especially in Asian population. No significant correlation was found between A1298C and RPL.