The Exploratory Development On Predicting Preterm Labor By The Measurement Of Cervical Length And Hosphorylated Insulin-like Growth Factor-binding Protein-1

Objective To evaluate the significance of cervical length measured by transab- dominal sonography and transabdominal sonography and phosphorylated insulin-like growth factor-binding protein-1 in predicting preterm labor in high-risk pregnant women in premature.Methods We chose 87 pregnant women in high risk for preterm labor who came to the obstetric department to do obstetric examination from July,2008 to August, 2009 with intact fetal membrane and no vaginitis. All of them firstly measured the cervical length by transabdominal sonography ,then done the Actim Partus test ,at the same time,we detected vaginal secretions routine,bacterial vaginosis.If the CL≤3.5cm,lastly,we measured the cervical length by transvaginal sonography. To take notes the gestational weeks and the CLwhen measured,then follow up their pregnancy Outcome, some of them not deliveryed in our hospital we have made a telephone to them.We devided preterm labor group and pregnancy delivery group by the outcome. All datas were analyzed with spss16.0 for windows software package.Results were analyzed by such statistical methods as chi-square (x~2) test,logistic regression analysis, independent-samples t test,and analysis of variance(ANOVA). (?)±S is refereed to means.For all comparisons a P value less than 0.05 was considered statistically significant. Results(1). The positive rate of phIGFBP-1 in preterm labor group and term birth group was respectively38.89%(7/18)and10.61%(7/66). There are statistically significant differences between the two groups (P<0.01). The sensitivity,specificity,positive predictive value and negative predictive value was 50%(7/14), 89.39%(59/66), 50%(7/14), 84.29%(59/70), respectively by phIGFBP-1.(2). The pregnancy women with CL≤4.0cm had a preterm birth rate of 29.17% (14 /48) and was also significantly higher than that ofthe women with CL﹥4.0cm who had a preterm rate of 11.11% (4 /36) ( P < 0.01) in the transabdominal . The sensitivity, specificity,positive predictive value and negative predictive value was77.8%(14/18),48.48%(32/66),29.17%(14/48),88.89%(32/36),respectively by 4.0cm or less of the cervical length measured by transabdominal sonography (TAS) .(3). The pregnancy women with CL≤2.5cm had a preterm birth rate of 85.7% (6 /7) and was also significantly higher than that of the women with CL﹥2.5cm who had a preterm rate of 15.58% (12 /77) ( P < 0.01) in the transvaginal . The sensitivity, specificity,positive predictive value and negative predictive value was33.3%(6/18),98.48%(65/66),85.71%(6/7),84.42%(65/77),respectively by 2.5cm or less of the cervical length measured by transvaginal sonography.(4). We measured the cervical length with CL≤3.5cm (measured by transabdominal sonography) by transvaginal sonography.The means of both methods were 3.02±0.30cm, 2.68±0.31cm,it is longer measured by transabdomi- nal sonography than by transvaginal sonography(P < 0.05). Both of them took associativity analyze,the result is they are intimate correlativity ( r= 0.5676, P < 0.001).(5). We devide preterm labor group, pregnancy delivery group and all of them three groups 24～28weeks group,28～32 weeks group,32～37 weeks group by the gestational weeks. There were no statistically significant Analysis of Variance (ANOVA) in interblocks, P >0.05.(6). The sensitivity, specificity,positive predictive value and negative predictive value was38.89%(7/18),66.67%(44/66),58.33%(7/12),91.67%(44/48),respectively by combined 4.0cm or less of the cervical length measured by transabdominal sonography (TAS) with phIGFBP-1.The sensitivity, specificity,positive predictive value and negative predictive value was 5.56%(1/18),84.85%(56/66), 50%(1/2),87.5%(56/64),respectively by combined 2.5cm or less of the cervical length measured by transvaginal sonography(TVS) with phIGFBP-1.(7). A stepwise multivariate logistic-regression model was devised to examine the independent contributions of factors such as cervicovaginal phIGFBP-1,CL,maternal age,gravidity,abortion times to the prediction of preterm labor.This model demonstrateded that Cervical length and phIGFBP-1 in cervicovaginal secretions are independent risk factors of preterm labor .The positive rates of phIGFBP-1 were with shorter CL;the correlation coefficient was 0.25(P=0.018).Conclusions(1). Cervical length and phIGFBP-1 in cervicovaginal secretions are independent risk factors of preterm labor .They have close relationship with the occurrence of preterm labor and can be used as the objective indicators for prediction of preterm labor.(2). Cervical length and phIGFBP-1 in cervicovaginal secretions can greatly enhance the positive predictive value and negative predictive value.The probability of preterm labor is about85.71%(the positive predictive value) when the2.5cm or less of the cervical length measured by transvaginal sonography,so intensive surveillance and medication are imperative in order to decrease the rete of preterm labor.Unnecessary obstetric interferences could be avoided for the pregnant negative for phIGFBP-1 and more then 4.0cm of the cervical length measured by transabdominal sonography as the probability of term birth is about 91.67%(the negative predictive value).(3). The cervical length measured by ultrasound is valuable in predicting preterm birth among the pregnancy women with high risk factors. When the transvaginal sonography isn't available, the cervical length measured by transabdominal sonography is also helpful.