A Meta-analysis Of Relationship Between The Folic Acid Or VitaminB12 Levels In Peripheral Blood And Preeclampsia

BackgroundPreeclampsia is a particular disease that occurs during pregnancy,characterized by hypertension and urine protein after 20 weeks of pregnancy,and the incidence rate of this disease is 4-6 %[1].Preeclampsia is closely related to intrauterine growth retardation and placental abruption,but its etiology and pathogenesis are unclear until now.In recent years,maternal nutrition deficiency as a high risk factor of PE has attracted more and more attention,but the conclusions are very different.Therefore,in view of the inconsistent conclusions of these studies to this question,our study collected case-control studies on blood folic acid and Vitmin B12 levels of preeclampsia between PE women and normal pregnant women.Using Meta-analysis to clear the relationship of blood folic acid and Vitmin B12 levels between normal pregnant women and preeclampsia.ObjectiveInvestigate the relationship of folic acid and vitamin B12 in blood between normal pregnant women and PE women through meta-analysis,in order to provide new clinical ideas for the prevention and treatment of preeclampsia.Method1.Studies retrievalWe searched studies comprehensively before August 28,2018 published on CNKI,Wanfang medical network,Pubmed,Medline,Embase and Cochrane Library about folic acid and vitamin B12 in blood between normal pregnant women and PE women,and combined with retrospecting references to get relevant studies.The Chinese key words including:preeclampsia,hypertensive disorders of pregnancy,gestational hypertension,vitamin B12,folic acid,vitamin B9.The English key words including:preeclampsia,folic acid,Vitamin B9,Vitamin B12.And we also searched the synonyms and abbreviations of the key words.2.Inclusion criteria and Exclusion criteriaInclusion Criteria:the case group were all PE patients with definite diagnosis,while the control group were healthy pregnant women without primary diseases;the type of studies was case-control study or cohort study;both case group and control group were single pregnancy studies;all the samples were collected from the peripheral venous blood for fasting food blood in the morning;the data of the study are expressed in the form of(M±SD)or(M±SE);languages of study are Chinese and English.Exclusion criteria:the patients were chronic hypertension,nephropathy,diabetes mellitus,hematological diseases and other primary diseases;the study of twin or multiple pregnancies;studies on non-fasting blood samples;low quality studies of NOS scores.3.The quality evaluation of studiesThe included studies were evaluated according to the NOS standard,and the total score is 9 points.However,0-4 points is divided into low-quality studies,5-9 points is divided into high-quality studies.4.Data extraction and statistical analysisData were extracted from the included studies,including author,year,age,sample size,gestational age,folic acid and vitamin B12.The extracted data were statistically analyzed by Rev Man5.3 software,but the publication bias analyzed by Stata oftware.Result1.The blood folate levels in the preeclampsia group were lower than in the healthy pregnant group,and the difference was statistically significant.2.The blood vitamin B12 levels in the preeclampsia group were lower than in the healthy pregnant group,and the difference was statistically significant.3.Subgroup analysis results showed that the blood vitamin B12 levels was associated with the severity of preeclampsia.But the blood folate levels was not related to the severity of preeclampsia.ConclusionBlood folate and vitamin B12 deficiency is closely related to the occurrence of preeclampsia.And the blood vitamin B12 levels was associated with the severity of preeclampsia.