The Predictive Value Of Cervical Length And Fetal Fibronectin For Preterm Birth In Twin Pregnancies:A Meta-analysis

Objective:A systematic evaluation of the value of cervical length(CL)and fetal fibronectin(f FN)alone or in combination to predict preterm birth in twin pregnancies was performed by meta-analysis.Methods:The literature on the predictive value of CL and f FN testing alone or in combination for preterm delivery in twin pregnancies was searched in Pub Med,The Cochrane Library,EMBASE,Web of Science,China knowledge Network Database,and Wanfang Journal Database according to a pre-established search formula.The literature was screened according to inclusion and exclusion criteria,and the required raw data were extracted from the final included literature and evaluated for quality using the Quality Assessment of Diagnostic Accuracy Studies-2(QUADAS-2).Statistical analysis was performed using Review Manager 5.3,Meta Di Sc 1.4 and Stata16.0,and comprehensive receiver operating characteristic curve(SROC)was drawn.Combined sensitivity(SEN),specificity(SPE),positive likelihood ratio(PLR),negative likelihood ratio(NLR),diagnostic odds ratio(DOR),and area under curve(AUC)were calculated.Q test and I~2 test were used to assess the magnitude of heterogeneity,and if heterogeneity existed,meta-regression and subgroup analysis were performed to explore the source of heterogeneity.Deek’s funnel plot was used to test for the presence of publication bias.Clinical utility was evaluated using Fagan’s column line plots.Finally,the combined effect sizes of the three forecasting methods are compared.Results:1.42 papers on the predictive value of CL for preterm delivery in twin pregnancies were included,with a total sample size of 5130 cases,and the combined effect sizes were:combined SEN,SPE,PLR,NLR,DOR and AUC with their 95%confidence interval(CI)of 0.67(0.59-0.74),0.77(0.69-0.83),2.9(2.23-3.76),0.43(0.35-0.52),6.78(4.67-9.85)and 0.78(0.74-0.81)respectively.2.23 papers on the predictive value of f FN for preterm delivery in twin pregnancies were included,with a total sample size of 2609 cases,and the combined effect sizes were:combined SEN,SPE,PLR,NLR,DOR and AUC and their 95%CIs of 0.72(0.63-0.79),0.81(0.71-0.88),3.70(2.44-5.63),0.35(0.26-0.46),10.56(5.82-19.17)and 0.82(0.78-0.85).3.11 papers on the predictive value of combined CL and f FN testing for preterm delivery in twin pregnancies with a total sample size of 1008 cases were included,with the following results:combined SEN,SPE,PLR,NLR,DOR and AUC and their 95%CIs:0.82(0.69-0.90),0.89(0.82-0.93),7.19(4.33-11.94),0.21(0.11-0.37),35.02(13.58-90.36)and 0.92(0.90-0.94).4.SEN was ranked in order of size as joint detection>f FN>CL;SPE was ranked in order of size as joint detection>f FN>CL;PLR was ranked in order of size as joint detection>f FN>CL;NLR was ranked in order of size as CL>f FN>joint detection;DOR was ranked in order of size as joint detection>f FN>CL;and AUC was ranked in order of size as joint detection>f FN>CL.Conclusions:CL,f FN and their combined tests are effective indicators for predicting preterm labor in twin pregnancies,and all of them have good clinical significance and practical value,but the combined test of CL and f FN has a higher predictive value for preterm labor in twin pregnancies than the two tests alone.