A Meta-analysis Of The Effect Of Levothyroxine On Pregnancy Outcomes In Pregnant Women With Positive Thyroid Peroxidase Antibody

Objective:To explore the effect of levothyroxine on pregnancy outcome of pregnant women with normal thyroid function and positive thyroid peroxidase antibody.Methods:We searched the literature on levothyroxine for pregnant women with normal thyroid function and positive thyroid peroxidase antibody by computer.The search scope included Cnki,Wanfang database,VIP database,China biomedical literature database,PubMed database and Embase database.The collected documents were mainly in English and Chinese,and the search time was between January 1990 and March 2020.The retrieved relevant literatures were screened according to inclusion criteria and exclusion criteria to obtain the final included literatures,and the data in the literatures were sorted out,get the final included literature,then extract the data in the literature,used Revman 5.3 software for meta analysis,calculated the RR value of each index,and through combining the difference of preterm delivery,abortion and other indicators of adverse pregnancy outcomes between the intervention group and the control group were compared to verify the effect of levothyroxine on the pregnancy outcome of women with normal thyroid function and thyroid antibody positive.Results:1.Literature screening: after the retrieval of the database,12 literatures were finally included,including 6 in English,6 in Chinese,11 in randomized controlled clinical trials,and a total of 2665 pregnant women were included.2.The results of meta-analysis showed that comparing the pregnant women with normal thyroid function and positive thyroid peroxidase antibody who were given levothyroxine with those who were not.The incidence of preterm birth was low(RR=0.44,95%CI[0.27,0.70],P=0.0006).The incidence of miscarriage was low(RR=0.60,95%CI[0.44,0.80],P=0.0006),The incidence of premature rupture of membranes was low(RR=0.63,95%CI[0.39,1.02],P=0.06),The incidence of fetal growth restriction was low(RR=0.34,95%CI[0.17,0.70],P=0.003),The incidence of gestational diabetes was low(RR=0.47,95%CI[0.32,0.68],P<0.0001).The differences in the incidence of premature rupture of membranes(RR=0.63,95%CI[0.39,1.02],P=0.06)and hypertensive disorders of pregnancy(RR=0.45,95%CI [0.12,1.70],P=0.24)and fetal distress(RR=0.68,95% CI[0.20,2.31],P=0.54)were not statistically significant.Conclusion:Levothyroxine intervention can reduce the incidence of miscarriage,premature delivery,fetal growth restriction and gestational diabetes mellitus in pregnant women with positive thyroid peroxidase antibody and normal thyroid function,but there is no significant improvement in the occurrence of hypertensive disorders of pregnancy and premature rupture of membranes.Therefore levothyroxine can improve the adverse pregnancy outcome of pregnant women with simple thyroid autoantibody positive.