Ultrasonographic Measurement Of Cervical Length Research Articles

Contribution of ultrasonography to the prediction of the induction-delivery interval: The ECOLDIA prospective multicenter cohort study

IntroductionTo evaluate the ability of preinduction ultrasonographic cervical length to predict the interval between induction and delivery in women at term with a Bishop score of 4 to 6 at induction. Study designThis multicenter prospective observational cohort recruited 334 women from April 2010 to March 2014. Inclusion criteria were women with singleton pregnancies at a gestational age ≥37 weeks, with no previous caesarean, a medical indication for induction of labor, and a Bishop score of 4, 5, or 6. All women underwent cervical assessment by both transvaginal ultrasound and digital examination (Bishop score). The induction protocol was standardized. The primary outcome measure was the induction-delivery interval. Hazard ratios (HR) and their 95% confidence intervals (95% CI) were used to assess potential predictors. ResultsMean gestational age at induction was 40.1 weeks, 60.8% of the women were nulliparous, and the cesarean rate was 13.4%. The mean induction-delivery interval was 20.8 h (± 10.6). Delivery occurred within 24 h for 56.9% (n=190) of the women. An ultrasonographic cervical length measurement less than 25 mm (HR=1.50, 95% CI 1.18–1.91, P<0.01) and parity (HR=1.41, 95% CI 1.21–1.65, P<0.01) appeared to predict induction-delivery interval. The cervical length cutoff to reduce the induction-delivery interval was 25 mm. ConclusionA cervical length cutoff of 25 mm was associated with shorter induction-delivery interval in women at term with a Bishop score of 4 to 6.

Transvaginal Ultrasound Cervical Length as an Indicator for Successful Induction of Labor

Background: Induction of labour is a common obstetric practice which refers to the process where the uterine contractions are initiated by medical and surgical means before the onset of spontaneous labour. The aim of this work was to evaluate the role of Preinduction transvaginal ultrasonographic measurement of cervical length as an indicator of a successful induction of labor. Methods: A cross-sectional study was carried out in Zagazig University Maternity Hospital during the period from May 2017 till November 2018. Included 171 pregnant women admitted for induction of labour.40 women delivered by Cesarean section (positive group) and 131 women delivered vaginally (negative group). All patients were subjected to full history taking, general, abdominal and pelvic examinations and investigations (including CBC, Rh, transvaginal ultrasound and non-stress test). All patients had vaginal examination for assessing the Bishop score before induction of labour and transvaginal ultrasound for assessment of cervical length. Results: Our study showed that the cervical length was significantly higher (31 ± 5.93 mm versus 22.61 ±3.67, p-value =0.00) and the Bishop Score significantly lower (5.95 ± 1.13 versus 7.87 ± 1, p-value = 0.00, respectively) in patients undergoing cesarean delivery compared with those delivering vaginally. Conclusions: Transvaginal ultrasonography proved to be better in predicting the success of induction of labor by having higher sensitivity, specificity, higher predictive value and better tolerability and less inter and intra observer variation.

Ultrasonographic Cervical Length Measurement at 10-14- and 20-24-weeks’ Gestation and Prediction of Preterm Delivery

Ultrasonographic Cervical Length Measurement at 10-14- and 20-24-weeks’ Gestation and Prediction of Preterm Delivery

Insulin-Like Growth Factor Binding Protein-1 versus Cervical Length in Prediction of Successful Induction of Labor after 37 Week. Observational Study

Bishop Score is still the usual method to expect the results of labor induction. Transvaginal ultrasonographic measurement of cervical length (TVUS-CL) is more objective and insulin like growth factor binding protein-1(IGFBP-1) has been recently used for this aim.

Insulin-Like Growth Factor Binding Protein-1 versus Cervical Length in Prediction of Successful Induction of Labor after 37 Week. Observational Study

Background: Bishop Score is still the usual method to expect the results of labor induction. Transvaginal ultrasonographic measurement of cervical length (TVUS-CL) is more objective and insulin like growth factor binding protein-1(IGFBP-1) has been recently used for this aim. Objective: This study was conducted to compare between TVUS-CL and detection of cervical (IGFBP-1) for prediction of results of induction of labor after 37 week of pregnancy. Patients and Methods: A prospective cohort study on 140 pregnant women underwent induction of labor. All patients were subjected to TVUS-CL and detection of cervical (IGFBP-1) and Bishop Score. The primary outcome measure was induction success. The secondary outcome measure was induction to delivery interval. Results: In our study (97) females delivered by simple vaginal delivery (SVD), (79) females delivered within 24 hour of induction, (18) females delivered after 24 hour, and (43) females delivered by caesarian section. The mean cervical length measured by TVUS in females who delivered by SVD was 24.89 ±5.48 mm and was 26.79±3.06 mm in those who delivered by CS. IGFBP-1 was positive in 71 females who delivered by SVD and in 17 females who delivered by CS and it was negative in 26 females who delivered by SVD and 26 females who delivered by CS. Conclusion: Success of labor induction correlated significantly with detection of cervical IGFBP-1 and measurement of cervical length by TVUS.

The Effect of Ultrasound-Measured Preinduction Cervical Length on Delivery Outcome in a Low-Resource Setting

Background Induction of labour is not without risk, and it calls for a method that will be sensitive enough to predict successful labour induction. Aim This study aims to evaluate the role of transvaginal ultrasonographic cervical length measurement at term in the prediction of successful induction of labour (IOL). Materials and Methods This prospective study was carried out in the Department of Obstetrics and Gynaecology of Federal Teaching Hospital Abakaliki between 1st of July and 30th of November 2015. Preinduction Bishop score and cervical length were assessed before induction of labour. Intracervical, cervical, extraamniotic Foley catheter was used to improve the Bishop score. The data were analyzed using the IBM SPSS Statistics 20. Results The mean maternal age of the study group was 30.68 ± 6.38 years with a range of 19–43 years. The mean gestational age and parity were 39.57 ± 1.49 and 1.85 ± 0.63, respectively. All the women studied had successful induction of labour with mean induction delivery time of 8.1 ± 3.0 hours and mean duration of labour of 7.4 ± 2.9 hours. Preinduction cervical length is a good predictor of a short duration of labour (P = 0.001). Parturient with a preinduction cervical length of less than 3 cm was likely to have labour lasting less than 6 hours (RR = 4.20 (95% CI 1.85–9.529). Conclusion Transvaginal sonographic measurement of cervical length provides a useful prediction of the likelihood of duration of labour following the induction of labour. It is recommended that IOL should be considered and success anticipated in a parturient with a cervical length less than 3 cm.

P06.01: Prediction of the outcome of labour in induced prolonged pregnancy by transvaginal ultrasonographic measurement of cervical length

Induction of labour is an intervention to artificially initiate uterine contraction leading to progressive dilatation and effacement of cervix and birth of the baby. The traditional method of predicting a successful vaginal delivery in induced labour is based on Bishop Score. This is subjective and had shown a poor predictive value of Bishop Score for the outcome of induction. The objective of this study was to correlate the preinduction cervical length measured by transvaginal ultrasonography (TVS) with the mode of delivery. This study was conducted in Department of Obstetrics and Gynecology for one year. One hundred pregnant women with prolonged pregnancy planned for induction of labour were included. Cervical length was measured by TVS prior to induction of labour. The primary outcome was the mode of delivery. The mean age was 23.84±4.56 years. Among 100 patients, 53% had vaginal delivery and 47% had Caesarean section. Primigravida were 63 and 37 were multigravida. On the basis of cervical length, the patients were divided into two groups. One group with cervical length ≤25mm and the other group with cervical length >25mm.There were 54 patients with cervical length ≤25mm and 46 patients with cervical length >25mm. There was a significant correlation between cervical length and mode of delivery with p<0.001.Those who had cervical length ≤25mm, 77.7% had vaginal delivery and 22.3% had Caesarean section. Among those who had cervical length >25mm, 23.9% had vaginal delivery and 76.1% had Caesarean section. There was also significant association of parity with cervical length. Comparing multigravida with primigravida with cervical length ≤25mm, 82.7% versus 72% had vaginal delivery. Similarly comparing multigravida with primigravida with cervical length >25mm, 37.5% versus 21% had vaginal delivery. Cervical length measured by transvaginal ultrasound can predict the outcome of induced labour in prolonged pregnancy. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Le dépistage universel de la longueur du col parmi les grossesses monofœtales sans antécédent d’accouchement prématuré est-il justifié ?

The ultrasonographic measurement of cervical length with a cutoff of 15mm is currently the best method to identify a group of asymptomatic women in the general population at risk of spontaneous preterm birth, especially among asymptomatic patients with a singleton pregnancy with no history of preterm birth. Cerclage and 17alpha-hydroxyprogesterone caproate (17OHP-C) are ineffective to reduce the risk of preterm birth among asymptomatic patients with a short cervix in midtrimester. However, vaginal progesterone (200-mg capsules of micronized progesterone or gel containing 90mg progesterone) has been demonstrated effective in 2large randomized trials to reduce the risk of preterm birth and possibly the composite morbidity and perinatal mortality associated among asymptomatic women with a short cervix in the general population screened by ultrasound of the cervix in midtrimester. Three cost-effectiveness analyses are converging to show that universal screening for cervical length with vaginal progesterone treatment seems to be cost-effective compared with no screening. However, it is too early to definitively conclude that universal screening is justified for several reasons: many women must be screened to prevent a relatively small number of preterm births. Moreover, the epidemiology of preterm delivery is such that the use of progesterone in asymptomatic women with a short cervix screened by ultrasound in midtrimester in the general population will not significantly reduce the prevalence of preterm births; there are no data comparing the effectiveness of universal ultrasound screening followed by vaginal progesterone treatment in case of short cervix versus no universal screening associated to a progesterone treatment in case of incidentally observed short cervix; the universal ultrasound screening may not produce the same results in practice than those observed in published randomized trials, due to population differences, "indication creep", or "stretching of the cutoff" defining the short cervix. Moreover, the implementation of unevaluated or not recommended treatments, such as bed rest, tocolytics, 17OHP-C or cerclage, can potentially cause unintended deleterious consequences and reduce the cost-effectiveness; the cost-effectiveness analyses evaluating universal screening for cervical length present uncertainties on critical variables, notably the short cervix prevalence and the progesterone efficacy. In conclusion, although the implementation of such a screening strategy can be considered by individual practitioners, this screening cannot be universally mandated.

Transvaginal cervical length measurement at 22- to 26-week pregnancy in prediction of preterm births in twin pregnancies

Objective: To investigate the predictive role of transvaginal ultrasonographic measurement of cervical length (CL) at 22–26 weeks of gestation in determining preterm deliveries in twin pregnancies.Methods: The study included 150 twin pregnancies. CL was measured by transvaginal ultrasonography at 22–26 weeks. Signs of preterm labor, ruptured membranes, vaginal bleeding, patients with systemic disease, and cervical incompetencies were excluded. The patients had monthly digital cervical examinations but no routine TVCL ultrasound examinations. The primary outcome was spontaneous preterm birth at before 37 weeks of gestation.Results: Ninety-two percent of twin pregnancies delivered by cesarean section and 16% babies had a neonatal intensive care unit requisitioned. Ninety-two patients were delivered in smaller than 37 gestational weeks and the mean CL measurement (CLM) was <37.64 ± 6.23 mm. According to the ROC curve analysis, CLM was found to be a discriminating parameter in patients. The area under the curve, cutoff values, sensitivity, and specificity were 0.794, 34.95, and 70–80%; respectively (p = 0.029).Conclusion: In women with twin pregnancy, the risk of preterm birth can be evaluated using the ultrasonographic measurement of CL at 22–26 weeks of gestation.

Predictive role of transvaginal ultrasonographic measurement of cervical length at 22-26 weeks of gestation for preterm deliveries in twin pregnancies

Predictive role of transvaginal ultrasonographic measurement of cervical length at 22-26 weeks of gestation for preterm deliveries in twin pregnancies

Predictive role of transvaginal ultrasonographic measurement of cervical length at 34 weeks for late pre-term and late-term deliveries in nulliparous women

Objective: To investigate the predictive role of transvaginal ultrasonographic measurement of cervical length (CL) at 34 weeks of gestation in determining late-preterm and late-term deliveries in nulliparous women.Methods: CL was measured by transvaginal ultrasonography at 34 weeks in 318 women (singleton, nulliparous, low-risk and vertex presentation). All women were followed-up till birth and delivered at hospital. Deliveries were classifed according to gestational week as late-preterm (340/7 to 366/7 weeks), term (370/7 to 406/7 weeks) and late-term (410/7 to 416/7 weeks).Results: There was a significant correlation between CL at 34 weeks and gestational week at delivery (r = 0.614, p < 0.001). Receiver-operating characteristic curve analysis showed that CL measurement below 25.5 mm predicted late-preterm delivery with a sensitivity of 80.0%, specificity of 93.9%, positive predictive value (PPV) of 52.6% and negative predictive value (NPV) of 98.2%; while CL above 42.5 mm had 70.4% sensitivity, 93.5% specificity, 50.0% PPV and 97.1% NPV in prediction of late-term delivery.Conclusion: Measurement of CL with transvaginal ultrasonography at 34 weeks of gestation can be of beneficial in predicting the risk of late-preterm and late-term deliveries in nulliparous women.

Prediction of spontaneous preterm birth using quantitative fetal fibronectin after recent sexual intercourse

The purpose of this study was to determine the effect of sexual intercourse on the accuracy of quantitative fetal fibronectin (qfFN) in the prediction of spontaneous preterm birth (sPTB) in asymptomatic high-risk women. This was a prospective masked predefined subanalysis of a larger study of cervicovaginal fluid qfFN concentration in high-risk women asymptomatic of preterm labor. Women who had sexual intercourse within 48 hours of qfFN testing (n = 61; 18(+0)-34(+6) weeks' gestation) were compared with controls from the same database without a history of pretest sexual intercourse, matched according to gestational age at testing and delivery, risk factor for sPTB, and ultrasonographic cervical length measurement. The median concentration of qfFN in women who had sexual intercourse within 48 hours of testing was 53 ng/mL (quartiles 6, 189), compared with 5 ng/mL (quartiles 2, 12) in the control group. The average qfFN concentration was 6.36 (95% confidence interval [CI], 3.43-11.8) times higher in the sexual intercourse group compared with controls (P < .0001). The false-positive rate was 56% (27 of 50) compared with 6% (3 of 52) in the control group (risk difference, 48%; 95% CI, 33-63; P < .001). The false-negative rate was 45% (5 of 11) vs 89% (8 of 9) in the control group (risk difference, -43%; 95% CI, -79 to -8; P = .043). Sexual intercourse within 48 hours of testing is associated with increased levels of fetal fibronectin in vaginal secretions and an increased rate of false-positive results in the prediction of sPTB in asymptomatic women.

Predictive Value of Cervical Length in Women With Threatened Preterm Labor

To assess the predictive role of ultrasonographic cervical length for preterm delivery in women with threatened preterm labor. A retrospective cohort study of women with singleton pregnancies who presented with preterm labor before 34 weeks of gestation and underwent ultrasonographic measurement of cervical length in a tertiary medical center. Women with cervical cerclage, cervical dilatation greater than 3 cm at presentation, and pregnancies complicated by placental abruption, clinical chorioamnionitis, stillbirth, or major fetal anomalies were excluded. The predictive accuracy of cervical length for preterm delivery was analyzed using both fixed thresholds and outcome-specific thresholds, which are associated with a detection rate of 90%, false-positive rate of 10%, or the inflexion point of the receiver operator characteristic curve. Between 2007 and 2012, 1,077 women presented with preterm labor and met the study criteria. The correlation between cervical length and the time interval to delivery was significant but weak (r=0.293, P<.001). Cervical length was independently associated with the risk of preterm delivery at less than 37, 35, and 32 weeks of gestation and within 14 and 7 days from presentation (a 4-7% decrease in the risk for each additional millimeter of cervical length) as well as with the time interval between presentation and delivery (each additional 2 mm was associated with an increase of 1 day). Overall, the accuracy of cervical length in predicting preterm delivery was relatively poor. Although cervical length is an independent predictor of preterm delivery in women with preterm labor, its predictive accuracy as a single measure is relatively limited. : II.

Prediction of spontaneous preterm delivery in the first trimester of pregnancy

ObjectiveTo develop a model for predicting premature delivery before 37 weeks’ gestation based on maternal factors, obstetric history and biomarkers in the first trimester of pregnancy. Study designCohort study based on data collected prospectively between 1 January 2000 and 30 November 2011. Multivariate logistic regression was used to construct a model of the risk of premature delivery. Results31,834 pregnancies were included, of which 1188 cases were spontaneous premature deliveries before 37 weeks (3.7%). We built a predictive model based on maternal age, body mass index, smoking status and previous obstetric history. This could identify 23.3% of premature deliveries in our study population, with a false positive rate of 10%. In the group of patients who had already had at least one pregnancy at or beyond 16 weeks, the detection level increased to 29.7%. The positive predictive value was 7.4 and 7.3% respectively, while negative predictive value was 97.2 and 97.9%. ConclusionsPredicting preterm delivery on the basis of maternal characteristics and obstetric history needs to be further improved. PAPP-A levels and ultrasonographic measurement of cervical length could not be integrated in the model but require further investigations.

Valeur prédictive du risque d’accouchement prématuré par la mesure échographique de la longueur du col utérin en cas de grossesse gémellaire

To assess ultrasonographic cervical length measurement in predicting preterm labor without premature rupture of the membrane in twin pregnancies. Retrospective study of 56 patients with preterm labor between 24+0 and 32+0 weeks. The judgment criteria was probability of delivery before 34 weeks in cases of spontaneous preterm labor before 32 weeks. The threshold of cervical length less than 20mm and 30mm respectively had a sensitivity of 42% and 94%, a specificity of 51% and 13%, a positive predictive value of 30% and 36% and a negative predictive value of 63% and 83% in predicting delivery before 34 weeks. Our results suggest that ultrasonographic measurement of cervical length is not a predictive of preterm delivery in twin pregnancies with preterm labor. However, the high negative predictive value allows to reassure the patient and to avoid hospitalization as well as tocolysis in cases where cervical length is superior or equal to 30mm.

P30.11: Ultrasound assessment of cervical length in labour induction: prediction of maternal and perinatal outcome

To evaluate the usefulness of sonographic assessment of cervical length in the prediction of maternal and perinatal outcome at the beginning of labour induction. We performed a prospective cohort study of 165 inductions of labor. Indications of labor induction were prolonged pregnancy (53.9%), pre-eclampsia (13.3%), fetal growth restriction (10.9%), gestational diabetes (9.7%), and others (12.2%). When the Bishop score was below 6 at admission, cervical ripening with prostaglandins was performed. Membrane rupture and intravenous oxytocin was used in all cases. Maternal and perinatal variables were collected prospectively. Analisys was performed by logistic regression analysis and ROC curves. The rate of cesarean delivery after induction was 23.6%, 46.7% of patients were nulliparous, and 16.7% of patients had a history of previous cesarean section. Mean gestational age at the inclusion was 39.7(1.6) weeks. Ultrasound cervical length areas under the ROC curve for prediction of Cesarean section were 75% (95% CI 62–83%; P = 0.04), and for the prediction of severe maternal complication 83% (95% CI 74–92%; P = 0.007). Cervical length of 20 mm was the best cut-off for the prediction of cesarean after labor induction (92% sensitivity and 68% specificity). Patients with a cervical length < 20 mm at the beginning of labour induction had a lower rate of cesarean sections (10.7% vs. 33.7%; P = 0.018) (OR 0.19 (CI 95% 0.05–0.76; P = 0.02)) and cesarean section for failed induction (7.1% vs. 24.7%; P = 0.045) (OR 0.16 (CI 95% 0.03–0.75; P = 0.03)) and a trend to reduced neonatal admission rate (3.6% vs. 15.1%; P = 0.101), umbilical artery pH below 7.20 (7.4% vs. 17.4%; P = 0.184) and severe maternal complications (0% vs. 7%; P = 0.151). Ultrasonographic measurement of cervical length at labour induction admission predicts maternal and perinatal outcome and the risk of Cesarean section.

Predicting mode of delivery using mid-pregnancy ultrasonographic measurement of cervical length

It has been recognized that preterm labor is related to short cervical length and that poor progress in labor is a major indication for cesarean section at term. We therefore hypothesize that long cervix is not associated with increased risk of cesarean delivery during labor at term. The objective is to determine the relationship between cervical length at mid-pregnancy and mode of delivery and preterm delivery. Trans-vaginal ultrasonographic scan measurement of cervical length was done for 281 pregnant women at a mean gestational age of 22 weeks. These women were followed up till delivery and the mode of delivery and the cervical length were analyzed for associations. Cesarean section due to poor progress in labor at term constituted 11.7%. The cesarean section for the highest quartile cervical length (40-67 mm) was 50% (P value 0.0018 for trend). Of the 33 women whose mode of delivery was cesarean section due to poor progress 18 (54.5%) had cervical length of more than 40 cm. The likelihood ratio of cesarean section due to poor progress of labor at term among women at the upper quartile cervical length is 10.28 (P value 0.0013) Long cervical length at mid-pregnancy predicts the possibility of cesarean delivery early in pregnancy. Hence, cervical length in mid-pregnancy can be of value in predicting the mode of delivery in early pregnancy.

Transvaginal ultrasonographic measurement of cervical length in asymptomatic high‐risk women with a short cervical length in the previous pregnancy

To determine if asymptomatic women at high risk of preterm delivery who had a short cervical length in their previous pregnancy and delivered at term are at increased risk of having a short cervical length in their next pregnancy, and whether they are at increased risk of preterm birth. This retrospective cohort study included high-risk (those with a history of spontaneous preterm birth, uterine anomaly or excisional treatment for cervical dysplasia) asymptomatic women who were pregnant with a singleton gestation delivering between April 2003 and March 2010, who had had a previous pregnancy and who had transvaginal ultrasonographic cervical length measurement performed at 16-30 weeks' gestation in both pregnancies. Comparison was among women who had a short cervical length (< 3.0 cm) in their previous pregnancy but delivered at term in that pregnancy (Short Term Group), women with a history of a normal cervical length (≥ 3.0 cm) in their previous pregnancy delivering at term (Long Term Group), and women who had a short cervical length (< 3.0 cm) in their previous pregnancy delivering preterm (Short Preterm Group). Primary outcomes were spontaneous preterm birth at < 37 weeks' gestation and cervical length. Secondary outcomes were spontaneous preterm birth at < 35 weeks and < 32 weeks, low birth weight, maternal outcomes and neonatal morbidity. A total of 62 women were included. Women in the Short Term Group were more likely to have a short cervical length in their next pregnancy compared with those in the Long Term Group (10/23 (43.5%) vs. 4/26 (15.4%), respectively) but not as likely as women in the Short Preterm Group (9/13 (69.2%); P=0.003). Women in the Short Term Group were not at an increased risk of spontaneous preterm birth at < 37 weeks in the next pregnancy compared with women in the Long Term Group (2/23 (8.7%) vs. 2/26 (7.7%), respectively), but women in the Short Preterm Group were at an increased risk (6/13 (46.2%); P<0.0001). Compared with women in the Short Term and Long Term groups, women in the Short Preterm Group were also at an increased risk of threatened preterm labor (6/23 (26.1%) and 4/26 (15.4%) vs. 9/13 (69.2%), respectively; P=0.002) and of receiving corticosteroids for fetal lung maturation (6/23 (26.1%) and 4/26 (15.4%) vs. 11/13 (84.6%), respectively; P<0.0001). Although high-risk asymptomatic women with a short cervical length in their previous pregnancy who delivered at term are at increased risk of having a short cervix in their next pregnancy, they are not at increased risk of preterm birth.

A predictive model of short cervix at 20–24 weeks using first‐trimester cervical length measurement and maternal history

To develop a model for the prediction of short cervix ( ≤ 15 mm) at 20-24 weeks by combining maternal history and transvaginal ultrasonographic measurement of cervical length at 11-14 weeks. To explore the value of an additional ultrasound examination of the cervix at about 17 weeks. Longitudinal prospective study in 800 unselected pregnant women presenting for first-trimester ultrasound assessment by nuchal translucency and serum biochemistry. Cervical length was evaluated transvaginally between 11 weeks and 13 weeks and 6 days (cx1), at 16-19 weeks (cx2) and 20-24 weeks (cx3). Backward multiple logistic regression analysis with cx3 ≤ 15 mm as the dependent variable was used to identify the predictors of a short cervix at 20-24 weeks. Cx1 and history of preterm delivery were significant independent contributors of a short cervix at 20-24 weeks [area under the curve (AUC 0.808, p < 0.001, Model) 1]. Furthermore, the cx1/cx2 ratio was a significant independent predictor of a short cervix at 20-24 weeks (odds ratio = 58.325 p = 0.012). The addition of the cx1/cx2 ratio improved the model (AUC = 0.878, p < 0.001, Model 2). A short cervix at 20-24 weeks can be predicted at the 11-14 weeks scan. The addition of a cervical measurement at about 17 weeks can improve the prediction model.

Transvaginal Ultrasonographic Measurement of Cervical Length as a Predictor of Preterm Birth

The advent of effective interventions to prevent preterm delivery such as 17 hydroxyprogesterone and cerclage serve as an impetus to determine whether routine second trimester transvaginal cervical length screening can identify which women would benefit from these therapies. A systematic review was conducted, 957 abstracts were screened, 234 articles underwent full-text review, and 23 studies were included in the final analysis including 26,792 women. Data from relevant studies were pooled to produce summary estimates of sensitivity, specificity, and likelihood ratios using a random effects model. The ideal criteria of transvaginal cervical length measurements to predict preterm delivery are discussed.