Meta Analysis Of The Effects Of Low-dose Aspirin On Pregnancy Outcomes In Preeclampsia High Risk Pregnant Women

ObjectiveHypertensive disorders complicating pregnancy is a group of diseases in which pregnancy and high blood pressure coexist,and the incidence is about 5%to 12%^[1].This group of diseases severely affects the maternal and child health,which is the main reason for the increased mortality rate of maternal and perinatal children^[1].Preeclampsia refers to a syndrome of hypertension and proteinuria that occurs after20 weeks of gestation,or no proteinuria,but there are multiple system dysfunction diseases such as reduced platelet count,hepatorenal insufficiency,pulmonary edema And cerebrovascular accidents and so on.It is currently believed that the underlying cause of preeclampsia is placental ischemia,which is associated with stress reactions,inflammatory reactions,and dysfunction of blood vessels and endothelial cells.This eventually leads to changes in the physiological status of pregnant women,resulting in hypertension,proteinuria,and other systemic functions.Disorders and other clinical manifestations^[2].The pathology is maternal systemic small vascular spasm,lumen stenosis,resulting in peripheral vascular resistance,some of the vascular endothelium damage,platelet repair and aggregation and release TXA2 and other factors to make the blood vessels to contract,forming a vicious cycle,high blood pressure,proteinuria,thrombosis and dirty Insufficient blood supply and other symptoms.At present,clinical treatment measures for preeclampsia are limited.The focus is on controlling acute hypertension,preventing eclampsia,and timely delivery.The only effective treatment is to remove the fetus and placenta^[3].Therefore,early prevention of preeclampsia is very important,especially in pre-eclampsia high-risk pregnant women.The key to prevention of preeclampsia is to detect hidden diseases and intervene in time before pregnancy or early pregnancy,such as autoimmune diseases,occult nephropathy,and hypercoagulable state of blood.The drug therapy is the basic pathological state of the corresponding treatment for maternal,aiming at different The goal has the duality of prevention and treatment.Low-dose aspirin can be used to prevent preeclampsia,and have been mentioned in some professional academic guidelines in Canada and the United Kingdom^[4-6].In recent years,the American Association of Obstetricians and Gynaecologists（ACOG）and the Chinese Medical Association have included low-dose aspirin during pregnancy as guidelines^[7-8].Studies have shown that aspirin can reduce the vasoconstriction,platelet aggregation,and antithrombotic effects by inhibiting the formation of TXA2,thereby alleviating the symptoms associated with hypertension,proteinuria,and organ organ ischemia.It has been reported in the literature that the difference in the role of aspirin in Asian populations is due to genetic polymorphisms such as cyclooxygenase 1,glycoprotein IIIa,and purinergic receptor P2Y^[9].Although there are relatively many studies on the use of aspirin in the prevention of preeclampsia,the clinical guidelines specify different treatment doses and treatment start and end times.There is still a lack of multicenter and large sample survey data for Asian populations to guide our country.The clinical prevention and treatment of preeclampsia high-risk pregnant women,aspirin for Asian and non-Asian preeclampsia high-risk pregnant women have no difference in the treatment effect is uncertain..The purpose of this study was to investigate the role of low-dose aspirin in the prevention of adverse outcomes in preeclampsia high-risk pregnant women and perinatal infants and different roles in Asian and non-Asian pregnant women.Information and Methods1 Research object1.1 Select document standard:Randomized,double-blind,controlled trials with Chinese or English as the language.1.2 Literature research object:（1）Subjects were preeclampsia high-risk pregnant women and divided into experimental group and control group;（2）Interventions:The experimental group was given oral aspirin 50-100mg/d.The control group received placebo and blank control;（3）Outcome measures included preeclampsia,premature delivery,intrauterine growth restriction,cesarean section,perinatal mortality,gestational hypertension,and placental abruption.2 Literature screening and quality evaluation2.1 The two researchers screened the documents separately,and then cross-checked the results.When there were inconsistencies in the opinions of the documents,they were discussed together with the third researcher or decided by the third researcher.2.2 All articles included in the study were evaluated according to the modified Jadad Scale,with a score of 1-3 for low-quality literature and 4-7 points for high-quality literature.3 data extractionThe literature including the author,publication year,interventions,outcome indicators,gestational age,and follow-up were extracted using the literature extraction scale.4 Statistical analysisStatistical analysis of the data was performed using the Cochrane Collaboration Meta software RevMan5.3.Count data were expressed using the odds ratio（OR）and its 95%confidence interval（95%CI）.Theχ² test was used to qualitatively analyze the heterogeneity among the included documents,and the quantitative assessment of heterogeneity was performed using I²quantitative analysis.If P<0.10 and I²≥50%,there is heterogeneity among the included literatures,and a random effect model needs to be used to perform meta-analysis;if P≥0.1 and I²<50%,there is no heterogeneity among the included literatures.Fixed effect model for meta-analysis.The combined statistic requires a Z test to calculate the probability（P）value of the statistic based on the u value.When P≤0.05,the statistic has statistical significance;when P>0.05,This statistic is not statistically significant.Result1 Literature search results and quality evaluationThe Chinese and English databases were searched for in the time span from January 1980 to January 2017.Finally,36 articles that fit the study were included,including 30 English articles and 6 Chinese articles.The total number of 32,241 cases was included.The quality scores of the included studies were all higher than 5 points and all were high quality studies.2 meta-analysis resultsThe meta-analysis showed that the incidence of preeclampsia was lower in the aspirin group compared with the control group（OR=0.73,95%CI:0.61 to 0.88,P<0.05）;the incidence of preterm delivery was lower in the aspirin group（OR=0.67,95%）CI:0.55-0.81,P<0.05);The incidence of intrauterine growth restriction in the aspirin group was reduced（OR=0.86,95%CI:0.79-0.95,P<0.05）;the perinatal mortality rate was decreased in the aspirin group（OR=0.81,95%CI:0.69-0.95,P<0.05）;the incidence of gestational hypertension in the aspirin group was reduced（OR=0.46,95%CI:0.29-0.75,P<0.05）;oral aspirin did not increase cesarean section rate（OR=1.00,95%CI:0.93-1.07,P=0.92）;oral aspirin did not reduce the incidence of placental abruption（OR=1.02,95%CI:0.82-1.28,P=0.84）.Subgroup analysis showed that aspirin can significantly reduce the incidence of preeclampsia in Asian and non-Asian high-risk pregnancies compared with controls.（OR=0.21,95%CI:0.13 to 0.34,P<0.05;OR=0.85,95%CI:0.73 to 0.99,P=0.03）;aspirin can significantly reduce the preterm birth rate among high-risk pregnant women in Asian and non-Asian（OR=0.31,95%CI:0.19 to 0.49,P<0.05;OR=0.76,95%CI:0.63 to 0.91,P<0.05）;Aspirin can significantly reduce the incidence of intrauterine growth restriction in high-risk pregnant women of Asian and non-Asian（OR=0.32,95%CI:0.18 to 0.57,P<0.05;OR=0.89,95%CI:0.81-0.98,P=0.02）;Early oral aspirin did not increase the cesarean section rate in cesarean sections of high-risk women in Asian and non-Asian populations（OR=0.88,95%CI:0.66 to1.18,P=0.40;OR=1.00,95%CI:0.93 to 1.08,P=0.91）;In the indicators of placental abruption in high-risk pregnant women of Asian and non-Asian,Early oral aspirin did not reduce the incidence of placental abruption（OR=1.07,95%CI:0.44 to 2.58,P=0.89;OR=1.02,95%CI:0.81 to 1.28,P=0.86）;Oral aspirin can not reduce perinatal mortality in Asian high-risk pregnant women（OR=0.56,95%CI:0.15-2.08,P=0.39）,but it can reduce the perinatal mortality rate of non-Asian high-risk pregnant women（OR=0.81,95%CI:0.70⁰.95,P=0.01）;oral aspirin can not reduce the incidence of gestational hypertension in non-Asian high-risk pregnant women（OR=0.66,95%CI:0.38 to 1.15,P=0.14）,But it can reduce the incidence of pregnancy-induced hypertension in Asian high-risk pregnant women（OR=0.25,95%CI:0.14 to 0.43,P<0.05）.Conclusion1 Oral low-dose aspirin during pregnancy can significantly reduce the incidence of adverse pregnancy outcomes in preeclampsia high-risk pregnant women and does not necessarily increase the rate of cesarean section and placental abruption in preeclampsia high-risk women.2 For the two outcomes of perinatal death and gestational hypertension,oral low-dose aspirin during pregnancy has a different effect on pregnant women with high pre-eclampsia in Asia and non-Asia.