Study On The Prediction Of Spontaneous Preterm Birth By Ultrasound

OUTLINEPremature delivery is a global problem that needs to be solved immediately, because it is seriously harmful to the health of the newborn. In 2010, there are about 14.9 million premature birth according to the globalized statistics, among which more than one million died. Moreover, every 30 seconds will see a death of the newborns due to premature delivery. Among those who survive through premature delivery, some partial neurological damage is irreversible.With the implementation of the comprehensive two-child policy in China, improving the health of perinatal babies and the quality of the population are very difficult tasks. Premature delivery ranks the second in the perinatal mortality, with congenital malformation the first, and the incidence rate are 5%?15%. Premature delivery at home and abroad are both high, and there is a rising trend. Although domestic and foreign scholars have done a lot of research on the pathogenesis and prevention of preterm labor, so far, the cause of premature birth is still not clear. At present, some biochemical index has been applied in the prediction of premature delivery, fetal fibronectin (fFN) has been widely used in clinical research and is reported more than other. In recent 10 years, domestic scholars pay more and more attention to the relationship between cervical length and premature, trying to predict premature delivery by monitoring the cervix, and then do some intervention treatment, so as to extend the gestational age and reduce perinatal mortality.Cervical evaluation has the following advantages in premature prediction:first, it is convenient, safe, inexpensive and repeatable to do transvaginal ultrasound observation of cervical. Second, short cervix is a reliable indicator that can be observed before preterm birth. Third, scholars at home and abroad have done a lot of research in terms of the cut-off value of preterm birth, which provides convenience for clinical work. Forth, for pregnant women with signs of threatened preterm labor, after clinical intervention can be monitored by transvaginal ultrasound at any time.This study will demonstrate the function of transvaginal ultrasound in predicting preterm delivery by studying the predicting ability of the examination method, transvaginal ultrasound examination on obstetric safety, cervical length, cervical anterior horn and cervical elastography.Part ?. The effect of transvaginal ultrasound on the apoptosis of human chorionic villus cells during pregnancyOBJECTIVE:To investigat the effect of transvaginal ultrasound on the apoptosis of human chorionic villus cells during early pregnancy.Methods:A total of 60 women who were undergone induced abortion in our hospital were randomly divided into control (<30s), short ultrasound (10 min) and long ultrasound (20 min) groups (N=20 each). Twenty-four hours after the ultrasonic exposure, chorionic villus tissues were extracted from induced abortion and were tested for cell apoptosis using flow cytometry. Bax and B cell lymphoma-2 (Bcl-2) protein levels were also quantified by immunohistochemical method. SPSS 17.0 software package was used to analyze all collected data, of which numeration data were presented as mean ± standard deviation (SD) and were analyzed by chi-square test. Measurement data were analyzed by analysis of variance (ANOVA). A statistical significance was defined when P<0.05.Results:Long ultrasound group had significantly higher apoptotic rates compared to short group, which had higher rates than control group (P<0.05 in both cases). Bax protein level showed elevation in long and short ultrasound groups (P<0.05). Bcl-2 proteins in two ultrasound groups, however, were down-regulated compared to the control group (P<0.05).Conclusion:Transvaginal sonography can potentiate the apoptosis of human chorionic villus cells possibly via increasing Bax/Bcl-2 protein ratio.Part. ?A comparative study of the cervical measurement in the middle term pregnancy by transperineal ultrasound, TPU and transvaginal ultrasound TVUObjective:To analyze and evaluate the difference of two kinds of ultrasonic inspection on cervical measurement.Methods:A total of 301 pregnant women were examined by ultrasound and transvaginal ultrasound during 22-24 weeks, recording the length of the cervix measured by two methods, their pregnancy was followed and the pregnancy outcome was recorded. SPSS 19.0 software package was used to analyze all collected data, of which numeration data were presented as mean ± standard deviation (SD) and were analyzed by chi-square test. Measurement data were analyzed by analysis of variance (ANOVA). A statistical significance was defined when P<0.05.Results:Among the 301 pregnant women,26 people did not accept transvaginal ultrasound examination, and the acceptance rate was 91.4%; all underwent transperineal ultrasonography, and the acceptance rate was 100%; 68 people were not satisfied with the results of transperineal ultrasound examination, and the display rate was 77.4%; transvaginal ultrasound examination showed that the rate of 100%.215 pregnant women were examined by transperineal ultrasound and transvaginal ultrasound at the same time. With CL?25mm as cut-off value, transperineal ultrasound examination revealed a short cervix in 19 cases, giving the incidence rate of 8.8%; transvaginal ultrasound examination revealed a short cervix in 21 cases, showing an incidence rate of 9.8%; two groups of cervical length are compared with by t test, two incidence rates were compared with by x2 test, and P> 0.05 showing no statistical significance of the difference.Conclusion:There is no significant difference in the measurement of the length of the cervix (P> 0.05) by transvaginal ultrasound, TVU and transperineal ultrasound TPU.Part?. Observation for the relationship between cervical length of the pregnant women in 11-13+6 weeks,22-24 weeks and 26-28 weeks and premature delivery by ultrasoundObjectiove:To explore the relationship between cervical length and preterm birth through observation of cervical length of pregnant women in 11-13+6 weeks,22-24 weeks and 26-28 weeks.Methods:A total of 325 pregnant women (a group of 23 people with a history of spontanous preterm delivery and 302 without that of it) in 11-13+6weeks,22-24 weeks and 26-28 weeks did cervical ultrasonography. During the inspection measurement of cervical length were processed under the resting state and Valsalva test. Through following the number of weeks for giving birth, a retrospective analysis were done to tell the differences between the group with a history of premature delivery and group with no history of preterm birth; the influence of Valsalva test for cervical length; variation in cervical length of the premature group and the mature group in 11-13+6 weeks,22-24 weeks and 26-28 weeks; the relationship between cervical length and premature delivery.SPSS 19.0 software package was used to analyze all collected data, of which numeration data were presented as mean ± standard deviation (SD) and were analyzed by chi-square test. Measurement data were analyzed by analysis of variance (ANOVA). A statistical significance was defined when P<0.05.Results:In 23 people of the premature group,7 people gave premature delivery, and the incidence of preterm birth was 30.4%. Among those 302pregnant women with no history of preterm, the number of premature delivery was 14, with 4.64% of the incidence. The rate of premature birth incidence in the history group was significantly higher than that without history of preterm group, and the difference was statistically significant (P<0.05); normal group (301) of 11-13+6 weeks and 22-24 weeks,26-28 weeks under resting and Valsalva test of cervical length was not statistically significant (P>0.05); cervical length of preterm labor group (21) in resting state and Valsalva test (CL), F-test analysis using ANOVA,11-13+6weeks and 22-24 weeks of cervical length difference was not statistically significant (P>0.05), there was statistical significance in 26-28 week gap (P<0.05); cervical length of preterm group in 26-28 weeks changed a lot but during 11-13+6 weeks,22-24 weeks did not change significantly; shortening of cervical length in normal group during11-13 +6weeks,22-24 weeks and 26-28 weeks were not obvious; CL<25mm, sensitivity of 22-24 weeks and 26-28 weeks for prediction of preterm labor were 75%,66.7%; but the missed diagnosis rate is 84.21%,57.89%; cervical lengths of 11-13+6 weeks in this study was greater than 30mm; for 26-28 weeks, CL>30mm, preterm birth rate was 2.87%.Conclusion:1.Valsalva test could show cervical shortening clearly of the preterm group at 26-28 weeks; 2.CL with 25mm as the cut-off value for prediction of preterm labor enjoyed a higher sensitivity;3. Premature delivery rate of late-term pregnancy, CL>30mm, is low; 4.The prediction by cervical length of 11-13+6week is low.Part?. Application of elastography in preterm deliveryObjective:To evaluate the effect of elastography on the prediction of spontaneous preterm labor by retrospective analysis of the results of the elastography about the internal cervical os of 158 pregnant women.Methods:The study included 158 pregnant women undergoing transvaginal ultrasound from Mar 2015 through May 2016, in 22-24 weeks they accepted elastography test for the inter os of the cervix and measurement of cervical length; in 26-28 weeks took test for cervical length measurement, and then calculated the percentage of cervical shortening. The elasticity of the cervix of the uterus was evaluated according to the color of elastography. Red and Yellow was the softest, then the green, then the blue and purple was the hardest. To observe and analyze the relationship between the elastography of the cervix of the uterus in 22-24 weeks and premature birth, and the relationship between the rate of cervical shortening in 26-28 weeks and preterm delivery..SPSS 19.0 software package was used to analyze all collected data,of which numeration data were presented as mean±standard deviation (SD) and were analyzed by chi-square test. Measurement data were analyzed by analysis of variance (ANOVA). A statistical significance was defined when P<0.05.Results:Of the 158 pregnant women,17 gave preterm birth, and the preterm birth rate was 10.76%; the incidence of preterm birth in red and yellow group of cervical elastography was 21.47%, significantly higher than that of green group 10.04%), blue and purple group (4.91%), and the difference was statistically significant, P< 0.05; cervical shortening rate of red and yellow group was 21.47%, significantly higher than that of green group (10.4%), blue and purple group (4.91%). The difference was statistically significant, P< 0.05.Conclusion:Elastography of cervix was helpful to the prediction of spontaneous preterm labor.PartV.Anterior uterocervica angle can be used as indicators of ultrasound in predicting preterm birthObjective:To determine whether a novel ultrasonographic marker, anterior uterocervical angle, correlates with risk of spontaneous pretermbirth.Methods:The study conducted a retrospective cohort study from Mar 2015 through May 2016 of singleton gestations between 22-24weeks undergoing transvaginal ultrasound for cervical length screening.Images were remeasured for anterior uterocervical angle between the loweruterine segment and the cervical canal.As the same time the they accepted elastography test for the inter os of the cervix.Primary outcome was prediction of spontaneous preterm birth<37 weeks by anterior uterocervical angle and secondary outcome evaluated cervical length and elastography.SPSS 19.0 software package was used to analyze all collected data, of which numeration data were presented as mean ± standard deviation (SD) and were analyzed by chi-square test. Measurement data were analyzed by analysis of variance (ANOVA). Logistic regression analysis of premature birth by cervical length, cervical anterior and elasticity imaging was established.A statistical significance was defined when P<0.05.RESULTS:A total of 234 women were studied. The rate of spontaneouspreterm birth in this cohort was 7.26% for delivery<37 weeks.Anterior uterocervical angle of 107 degrees was significantly associated with spontaneous preterm birth<37 weeks with sensitivity of35.7%(P<.005). Cervical length<25mm significantly predicted spontaneous preterm birth<37 weeks with sensitivity of66.7%(P<.005).For the comprehensive evaluation of cervical length, anterior cervical angle and elastic imaging on influence of preterm birth in pregnant women with CL<25mm or CL= 25mm, ACA>107°or ACA(?)= 107°, red and yellow, green, blue and purple as the independent variable, the occurrence of preterm or term pregnancy as the dependent variable, established Logistic regression model.It was found that the maximum ACA>107°partial regression coefficient was 2.551, EXP (B) was 12.822, which showed that the risk of preterm birth was 12.822 times higher than that of ACA< 107 °. Secondly, the preterm birth risk of red and yellow in elastography was increased by 4.557 times. And CL<25mm of pregnant women, although the EXP (B) value was high, but the statistical test was no significant (P>0.05).The area under the ROC curve was 0.557, while the area under the ROC curve for ACA was 0.816, the ROC curve for elastography was 0.757.CONCLUSION:A wide anterior uterocervical angle>107 degrees detected during the second trimester was associated with an increased risk for spontaneous preterm birth<37W.