Transabdominal Cervical Length Research Articles

DIAGNOSTIC ACCURACY OF TRANSABDOMINAL SONOGRAPHY IN DIAGNOSING SHORT CERVICAL LENGTH KEEPING TRANSVAGINAL SONOGRAPHY AS THE GOLD STANDARD

Background: Transvaginal ultrasound is a gold standard technique for diagnosing short cervix. This study aimed to determine the diagnostic accuracy of transabdominal sonography (TAS) in diagnosing short cervical length in 20–28 week pregnant women keeping transvaginal ultrasound as the gold standard. Methods: It was a cross-sectional study, conducted in the Department of Radiology, DHQ Hospital, Narowal from 1st July 2023 to 1st March 2024. A total of 321, 20–28 week pregnant women were included. Cervical length was measured initially by transabdominal ultrasound followed by transvaginal ultrasound. Results: Of the total 321 patients, 264 were true negative, 28 were false negative, 14 were false positive and 15 were true positive. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of TAS in assessing accurate cervical length are 34.8%, 94.8%, 51.7%, 90.4%, and 86.9% respectively. In all cases with transabdominal cervical length >35 mm, the NPV of transabdominal ultrasound reached 100%. Conclusion: TAS exhibits limited accuracy in correctly identifying short cervical length in women who indeed have a short cervical length. However, it demonstrates a strong ability to exclude short cervical length in women with a normal cervical length. Cervical length measured via transabdominal ultrasound can be reliably reported as safe if it exceeds 35 mm. For measurements below it, further evaluation with transvaginal ultrasound is recommended. Pak J Physiol 2024;20(3):49–52, DOI: https://doi.org/10.69656/pjp.v20i3.1651

Transabdominal-transvaginal ultrasound cervical length sequential screening to predict the risk of spontaneous preterm birth in singleton pregnancy women with low risk of preterm birth

Objective: To investigate the feasibility of predicting the risk of spontaneous preterm birth in singleton pregnancy women with low risk of preterm birth by transabdominal-transvaginal ultrasound cervical length sequential screening in the second trimester. Methods: This prospective longitudinal cohort study included singleton pregnant women at 11-13+6 gestational weeks who were admitted to Nanjing Drum Tower Hospital from January 2023 to September 2023. Transabdominal and transvaginal cervical lengths were measured during the mid-trimester fetal ultrasound scan at 18-24 weeks, and pregnancy outcomes were obtained after delivery. A short cervix was defined as a transvaginal cervical length of ≤25 mm, and the outcomes were defined as spontaneous preterm birth occurs between 20 and 36+6 weeks and extremely preterm birth before 32 weeks. The area under the receiver operating characteristic (ROC) curve was used to evaluate the effectiveness of predicting spontaneous preterm birth by transabdominal and transvaginal cervix length, as well as the effectiveness of predicting short cervix by transabdominal cervical length. The relationship between transabdominal and transvaginal cervical length was evaluated using a scatter plot. Results: A total of 562 cases were included in this study, comprising 33 cases of spontaneous preterm birth (7 cases occurring before 32 weeks) and 529 cases of term birth. (1) Compared to the term birth group, transabdominal cervical length (median: 37.6 vs 33.2 mm; Z=-3.838, P<0.001) and transvaginal cervical length (median: 34.0 vs 29.9 mm, Z=-3.030, P=0.002) in the spontaneous preterm birth group were significantly shorter. (2) The areas under the ROC curve for predicting spontaneous preterm birth by transabdominal and transvaginal cervical length were 0.699 (95%CI: 0.588-0.809) and 0.657 (95%CI: 0.540-0.774), respectively. The sensitivity, specificity and positive predictive value of transvaginal cervical length Conclusions: In singleton pregnancy women with low risk of preterm birth, transabdominal-transvaginal cervical length sequential screening can reduce unnecessary transvaginal ultrasounds by approximately 41% without missing the diagnosis of pregnant women with a short cervix. This method also enhances the effectiveness of transvaginal cervical length to spontaneous preterm birth.

Introduction of universal transvaginal cervical length measurement does not decrease spontaneous preterm delivery rate compared to universal transabdominal screening with reflex cut‐off: A pre‐post study

AbstractObjectivesThe objective of our study is to examine cervical length measurements, identification of short cervix, vaginal progesterone use, and rate of spontaneous preterm delivery before and after departmental transition to a universal transvaginal ultrasound screening protocol from a universal transabdominal screening protocol.MethodsThis is a retrospective observational pre–post study examining the year prior to and year following a transition to a universal transvaginal ultrasound screening protocol to assess cervical length at the time of the anatomy survey. Prior to this transition, universal transabdominal cervical length screening was performed, with reflex transvaginal ultrasound measurement if transabdominal measurement was &lt;35 mm or was unable to be obtained.ResultsA total of 1760 charts were reviewed; 962 charts were from the pre‐transition/transabdominal year and 798 charts were from the post‐transition/transvaginal year. In the post‐transition/transvaginal year, cervical length less than 20 mm was identified in 1.5% of cases, compared to 0.7% of cases in the pre‐transition/transabdominal year (p = 0.114). There was no difference in the rate of spontaneous preterm delivery between the two groups (5.1% in the pre‐transition/transabdominal year vs. 6.9% in the post‐transition/transvaginal year; p = 0.111).ConclusionsIn this pre‐post study, introduction of a universal transvaginal cervical length screening did not decrease spontaneous preterm delivery rates or detection of short cervix &lt;20 mm, compared to a protocol of universal transabdominal cervical length screening with reflex to transvaginal for measurement &lt;35 mm.

Routine transabdominal cervical length screening in mid-pregnancy for the prevention of preterm birth: Is it good enough to use as a screening test?

Preterm birth (PTB) is a major pregnancy complication. There is evidence that a short cervical length in mid-pregnancy may predict women at increased risk of PTB. To evaluate the utility of population-based, transabdominal cervical length (TACL) measurement screening in mid-pregnancy for PTB prediction in women. A transabdominal approach was initially performed, with a transvaginal (TVCL) approach offered when the TACL was <35 mm, could not be accurately measured, or the pregnancy had risk factors for PTB. TACL was compared to the directly related TVCL, when both were performed at the same assessment. Women with risk factors of PTB were included when they had both TACL and TVCL measurements performed at the same visit. Data were provided for 9355 singleton pregnancies from 13 participating imaging centres. A transabdominal approach was used in 9006 (96.3%), including 682 (7.3%) TVCL combined with TACL. There were 349 (3.7%) women who had TVCL only. The median TACL was longer (40 mm) than the TVCL (38 mm). In 682 paired TACL and TVCL measurements, TACL <35 mm correctly identified 96.2% of pregnancies with TVCL <25 mm, compared with 65.4% of cases when using a TACL <30 mm. A TVCL <25 mm occurred in 59 (0.6%) women. A TACL <35 mm was associated with birth <37 weeks of gestation in 12.1% of women and birth <32 weeks of gestation in 3.9%. Universal TACL is a feasible option for population screening of cervical length in a low-risk population, progressing to TVCL if the TACL is <35 mm or the cervix cannot be transabdominally accurately measured.

Comparison between trans-vaginal and trans-abdominal ultrasound examination of the cervix in the second trimester of pregnancy: a prospective study.

To compare transvaginal (TV) and trans-abdominal (TA) ultrasound assessment of cervical length (CL) at the time of the second-trimester scan for fetal anomalies. This was a prospective study including consecutive pregnant women attending the low-risk ultrasound clinic of two fetal medicine centres in Italy. The inclusion criteria were women between 19+0 and 22+0weeks of gestation, attending the prenatal ultrasound clinic for the routine second trimester screening for fetal anomalies. The primary outcome was to compare the CL measurement obtained at TV compared to TA ultrasound; the secondary outcome was to report the inter and intra-observer variability of CL measured with the two different approaches. All women underwent TV and TA assessment of the cervix performed by two experienced certified operators, blinded to each other. Intra-class correlation coefficients (ICC) and Bland-Altman analyses were used to analyse the data. Two hundred and fifty women were included in the analysis. All women had anteverted uterus. The mean gestational age at ultrasound was 20.7±0.7weeks; 1.2 % (3/250) scans were performed at 19weeks, 49.2 % (123/250) at 20weeks, 44.8 % (112/250) at 21weeks and 4.8 % (12/250) at 22weeks of gestations. Identification of the major landmarks of CL at TA ultrasound was achieved in all the included cases. There was good reliability between CL measured at TA (ICC 0.95, 95 % CI 0.93-0.97 for observer 1 and 0.92 %, 95 % CI0.89-0.94 for observer 2) and TV ultrasound 0.97, 95 % CI0.96-0.98 for observer 1 and 0.96, 95 % CI 0.95-0.97 for observer 2). There was also good reliability between the two observers for both the TA and TV assessment of the CL. Mean TA CL was 41.4±5.5 for observer 1 and 40.5±4.8 for observer 2 with no significant differences between the two measurements (mean difference 0.92 mm, 95 % CI-9.7 to 11.2). Likewise, there was no difference between the CL measured at TV ultrasound between the two observers (mean difference-0.83 mm, 95 % CI-5.97 to 4.30). Finally, there was no difference in the mean CL measured at TA compared to TV, either considering the overall population of women (mean difference:-0.43, 955 CI-8.65 to 7.79), or when stratifying the analysis according to the parity status and the operator. Among experienced operators, there was no difference between TV and TA ultrasound assessment of the CL at the time of the routine anomaly scan for fetal anomaly.

The effect of preinduction cervical length measurement with three different ultrasonographic methods on predicting delivery time.

This study aimed to evaluate the effect of preinduction cervical length (CL) measurement by transvaginal (TV), transperineal (TP), and transabdominal (TA) ultrasonography (USG) on the time of delivery and to compare these three sonographic methods in terms of superiority over one another. This study included TV, TP, and TA CL measurements in pregnant women who were planned to undergo induction of labor at 37 weeks' gestation or later. The correlations between the said three methods and BISHOP scores were evaluated. These three methods were compared in terms of superiority in predicting the time of delivery. Pregnant women at 37-42 weeks' gestation undergoing labor induction were included, and all three methods were used for CL measurements. Three methods were correlated with each other (p < 0.001) and with BISHOP scores (p < 0.001). The correlation between all three methods and BISHOP scores indicates that TP and TA USG can be used instead of TV USG. On the other hand, while TA USG did not give a clear result in the accurate estimation of vaginal delivery time, TP, and TV USG gave both accurate and close results. When all these data are evaluated, it is concluded that TPU can be used safely instead of TVU, especially in patients receiving induction.

EP19.21: Transabdominal cervical length screening in mid‐pregnancy for preterm birth prevention: the impact of image quality on cervical length measurement

EP19.21: Transabdominal cervical length screening in mid‐pregnancy for preterm birth prevention: the impact of image quality on cervical length measurement

Intra-Sonographer Correlation Between Transabdominal and Transvaginal Cervical Length Measurements and Associated Patient Demographics.

To assess transvaginal (TV) and transabdominal (TA) cervical length (CL) measurements' variability and patient factors associated with TA CL accuracy. We hypothesized that patient factors would affect the accuracy of TA CL. This was a prospective cohort study. During anatomy ultrasound, TA and TV CL measurements were obtained, distance from placental edge to internal cervical os assessed, and demographic questionnaires completed. Patients between 18 to 22 weeks and 6 days were included and those <18 year old or with a twin gestation were excluded. TA CL >0.5 cm different from TV length was considered inaccurate. A total of 530 patients were included. Exactly 18.7% had a prior cesarean, 9.8% a preterm birth, and 2.2% a cervical procedure. Mean age and BMI were 31.1 years and 27.8 kg/m2 . Median number of living children was one. Median TA and TV CL were 3.42 and 3.53 cm. Exactly 36% (95% CI: 32-40%) of TA CL measurements were inaccurate. CL of 3.4 cm corresponded to a mean difference of zero between TA and TV CL. TA ultrasound had a sensitivity of 25% and a specificity of 98.5% to detect TV CL <2.5 cm. On multivariable analyses, Hispanic ethnicity was associated with inaccurate TA measurement (OR 0.48, 95% CI: 0.24-0.96, P = .04). On average, TA CL underestimates TV CL when TV CL >3.40 cm and overestimates TV CL when TV CL <3.40 cm. Additional co-variates did not impact accuracy. TA ultrasound has low sensitivity to predict short cervix. Relying solely on TA CL to identify those who need intervention may miss diagnoses. It may be reasonable to develop protocols in which TV CL is used for TA CL <3.4 cm.

Transabdominal and transvaginal ultrasound assessment of cervical length - can transvaginal approach be avoided?

This study aimed to compare transabdominal (TA) and transvaginal (TV) ultrasound assessment of cervical length during pregnancy and to establish cervical length above which transvaginal measurement is not necessary. Cervical length was measured using TA and TV method in the first (11 + 0-13 + 6 weeks), the second (20 + 0-21 + 6 weeks) and the third trimester (28 + 0-31 + 6 weeks) in 250 women with singleton pregnancy and low risk for preterm birth. If the cervical length measured in the second trimester of pregnancy with transabdominal approach is ≥ 28.5 mm and ≥ 30.5 mm in the third trimester, it can be assumed with 100% sensitivity the cervical length measured with transvaginal method will be > 25 mm. Transabdominal cervical length measurement in the second and third trimester allows 89% and 65% of patients, respectively, to avoid transvaginal scan. Second and third trimester screening by transabdominal cervical length measurements in a group of pregnant women with low risk for preterm birth is useful to determine which patients require transvaginal measurement.

Consistency in the transabdominal ultrasound measurement of cervical length in mid-pregnancy.

The Western Australian Preterm Birth Prevention Initiative recommends a transabdominal cervical length (TACL) measurement at the mid-pregnancy ultrasound to screen low-risk women for preterm birth risk. In view of this recommendation, we assessed the inter-observer consistency of TACL screening in mid-pregnancy. Routinely collected mid-pregnancy TACL ultrasound images were graded from 0 to 4 according to the anatomical landmarks identified by a single expert. A random selection of 10 images of each grade were disseminated in an electronic survey to determine inter- and intra-observer variations in the classification of the cervical image. A total of 244 participants graded 50 TACL images. Six participants repeated the grading. Overall agreement to the exact initial grade for all images was 49.6%, highest for images at both ends of the spectrum (83% Grade 0 and 70.4% for Grade 4). Overall agreement to the initial diagnostic Grades 3 and 4 was 75.3% (95% CI 74.5-76.0%) and was higher when the maternal bladder was empty. There was moderate inter-rater agreement (κ = 0.42) for Grades 3 and 4 (diagnostic) or Grades 1 and 2 (non-diagnostic). The intra-rater agreement was fair to good (κ = 0.59, 95% CI 0.49-0.70) for those who repeated the assessment (including the expert grader). Sonographic CL screening is considered an important tool for the identification of women at high risk of preterm birth. Image classification of TACL performed poorly compared with previous studies assessing transvaginal cervical length. Improved reliability and measurement consistency may be achieved through high levels of quality assurance, ongoing training and image audit.

The perceptions of obstetric care providers about cervical length screening for preterm birth prevention.

Routine cervical length (CL) measurement at the mid-pregnancy ultrasound is a central recommendation of the Western Australian Preterm Birth Prevention Initiative (Initiative). To evaluate the perceptions and changes in practice of Western Australian obstetric care providers regarding routine CL screening for preterm birth (PTB) prevention following the Initiative introduction. Two self-administered questionnaires were completed by providers from a range of practices. The first was during site visits with the Initiative Outreach team in 2015-2016. The questionnaire was re-issued in 2021 via online dissemination. Participant demographic data and opinions on CL screening for PTB prevention were collected. Two hundred and fourteen providers participated in 2015-2016 and 109 in 2021. In both surveys, providers were more likely to discuss transvaginal CL screening with high-risk women (48.1%, 76.1%; P<0.001) compared with low-risk (7.5%, 18.3%; P=0.002) and the importance of CL screening (13.5%, 40.4%; P<0.001), in 2015-2016 and 2021, respectively. Responses relating to CL screening, including what constitutes a short cervix on ultrasound were varied. A transabdominal CL <35mm was classified as short by 46.2% and 37.6% and <25mm on transvaginal ultrasound by 49.1% and 64.2%, in the respective surveys. Most providers ceased progesterone (68.6%, 75.2%) at >28weeks gestation. Providers focused on women with overt PTB risk factors, rather than a universal CL screening approach. Although there was improvement between the surveys, the definition of what constitutes a short cervix on ultrasound and how to treat and monitor women with a short CL remained varied.

Cervical Length Assessment during Pregnancy Using Ultrasound Measures in Duhok City

Preterm birth has been regarded as a major cause of perinatal morbidity and mortality with an incidence ranging from 5-18 % worldwide. Early screening of pregnant women at risk of preterm delivery and managing it correctly are essential aids to reduce the predictable complications associated with prematurity Objective: The main aim of the study was to assess the true and acuurate cervical measuremants that predict the clear definition and cut values of the cervical incompetence in second trimester pregnant women by using transabdominal and transvaginal Ultrasound . More specofc aim of the study was looking for the accuracy of transabdominal ultrasound in measuring the cervical length for prediction of preterm birth when compared with transvaginal ultrasound, assessment of the mean cervical lengthin the second trimester pregnancy , the correlation between both of these modalities in each case , finding the clear cut off value of transabdominal Ultrasound measurement to be further assessed by transvaginal Ultrasound . Materials: A cross sectional prospective study done on ninety-three pregnant women between 12-22 weeks of gestation who were referred between March to November of 2018in thisprospective study ,their cervical lengths were assessed by using transabdominal Ultrasound , using Transvaginal Ultrasound as the reference, both methods were correlated forvariance. Results: The mean transabdominal cervical length measurements was seen to range (34.3 ± 5.8 mm) while the mean transabdominal cervical length measurements was seen to range (35.9 ± 4.4 mm). The mean transabdominal cervical length was shorter than the mean transvaginal cervical length by an average of 1.6 mm. The 10th percentile of transabdominal and transvaginal cervical length was 27 mm and29.4 mm, respectively. The two groups that showed significant difference between the two scanning methods were the 25th-50th centile group (TACL) of 33-37 mm) with p = 0.019, and the 50th-75th centile group (TACL) of 37-40 mm) with p =0.001 , the clear cut value of 27 mm was the value considered to revert fron TAUS to TVUS for CL assessment Conclusion:TAUS was found to be an initial CL screening method in the second trimester pregnant women generally while from 12- 14 weeks GA specifically the TVUS is preferred for this measurement ,a cut-off value of 27 mm is used to revert to TVUS for CL assessment instead of TAUS. &nbsp;

Comparison of Transabdominal and Transvaginal Sonograms in Evaluation of Cervical Length During Pregnancy

Objective: A short cervix during pregnancy indicates a higher risk of preterm delivery. Transvaginal sonography is widely used for the detection of a short cervix. The literature indicates that 21–24 weeks is the most sensitive gestational age to assess transvaginal cervical length (TV CL) of ≤2.5 cm for potential preterm delivery. Pregnancies between 18 and 20 weeks’ gestation are generally performed transabdominally; thus, it could be beneficial to have a recognized correlation between the transabdominal cervical length (TA CL) measurement and the TV CL measurement at this earlier time period. Materials and Methods: An online database search produced 13 research articles to be reviewed. Inclusion criteria consisted of TA CL and TV CL assessment of singleton pregnancies with intact membranes. Results: Findings indicate high diagnostic yield when a TA CL of &lt;2.9 cm or TV CL of &lt;2.5 cm is used for defining a shortened cervix when measured between 18 and 20 weeks’ gestation. Conclusion: This review of the literature indicates a correlation between average TA CL and average TV CL measurements, although the relationship widens as CLs become shorter.

It is about time. The advantage of transabdominal cervical length screening

Purpose Sonographic cervical length (CL) measurement has become a standard practice for identifying women at increased risk for preterm birth. We aimed to assess the time needed for CL measurement during fetal anatomy scan using either transabdominal or transvaginal ultrasound, and to provide a predictive value of the transabdominal CL measurements for reassuring transvaginal CL measurements of more than 25 mm. Methods In a prospective study we measured CL transabdominally, and transvaginally in all the anatomy scans performed at 18–25 weeks’ gestation, from January 2017 until January 2018. CL and the duration of the examination were compared between the two approaches. Adjustments were made for, body mass index, previous cesarean sections and parity. Results Four hundred sixty-eight patients participated in the study. The time needed for the transabdominal CL measurement was significantly lower compare with the transvaginal CL measurement (0.46 ± 0.3 min versus 6.9 ± 1.38 min, p < 0.001). The CL measured transabdominally was significantly shorter than the CL measured transvaginally (36.7 ± 6.7 mm versus 41.9 ± 7.3 mm, respectively p < 0.001). All women with transabdominal CL measurements above 36 mm (64.2% of patients) had a transvaginal CL of more than 25 mm. Conclusion Transvaginal measurement of CL is a time-consuming procedure that prolong fetal anomaly scan by 25%. Transabdominal CL measurement of 36 mm is reassuring CL above 25 mm. Transabdominal ultrasound should be used as an initial tool for CL screening. Transvaginal measurements of CL should be reserved for high-risk women, for women with difficulties in demonstrating the cervix abdominally, and for women with transabdominal measurements of less than 36 mm.

Ultrasonographic Transabdominal Measurement of Uterine Cervical Length for the Prediction of a Midtrimester Short Cervix.

This study was aimed to estimate the value of transabdominal (TA) ultrasound measurement of cervical length (CL), as an alternative of transvaginal (TV) ultrasound, for universal screening of short cervix in the midtrimester. We conducted a prospective cohort study of nulliparous women with singleton pregnancy at 20 to 24 weeks of gestation. All participants underwent TA ultrasound followed by TV ultrasound with acquisitions of images and videos of the uterine cervix. A second sonographer, blinded to the participants' data and pregnancy outcomes, measured the CL using TA and TV images and videos. Pearson's correlation test and receiver operating characteristic (ROC) curve analyses were performed. A total of 805 participants were recruited, including 780 (97%) where TA CL measurement was feasible. We observed a strong correlation of CL between TA and TV (correlation coefficient: 0.57; p < 0.0001) with a mean TA measurement being 4 mm (95% confidence interval [CI]: -6 to 14 mm) below the mean TV measurement (mean of differences: 5 ± 4 mm). We observed that a TA CL <30 mm was highly predictive of a short cervix defined as a TV CL ≤25 mm (area under the ROC curve: 0.97; 95% CI: 0.95-0.99; p < 0.0001) with a sensitivity of 100% and a false-positive rate of 22%. Universal short cervix screening in nulliparous women could be performed using TA ultrasound, which could allow the avoidance of TV ultrasound in more than three quarter of women. In low-risk population, TV ultrasound could be reserved to women with TA CL <30 mm. · Cervical length (CL) measurement with transabdominal (TA) ultrasound is feasible in most cases and is strongly correlated with CL measured with transvaginal (TV) ultrasound.. · Using a cut-off of 30 mm for TA ultrasound as a first-step screening of short cervix in nulliparous women, three-quarter of TV ultrasound could have been avoided.. · Use of TA CL screening could alleviate some of the logistical challenges of universal TV CL screening..

P01.01: Transabdominal cervical length measurements above 35mm exclude short cervix in both twin and singleton pregnancies

To evaluate the discrepancies between transabdominal and transvaginal sonographic measurements of the cervix in singleton and twin pregnancies and to assess whether maternal weight influences these discrepancies. A prospective cohort study. Transabdominal and transvaginal cervical lengths measurements were obtained before and after voiding (respectively) in pregnant women between 14 and 25 weeks of gestation. Measurements were compared between singleton and twin pregnancies and correlated with maternal age, and BMI. Statistical analysis was performed in order to determine a transabdominal cervical length cut-off with 100% confidence for transvaginal cervical length above 30mm. 52 pairs of twin pregnancies and 388 singleton pregnancies were included. The mean cervical length measured abdominally for twin and singleton pregnancies was 35.6 ± 5.3mm and 36.8 ± 6.9mm respectively. The mean cervical length measured vaginally was 40.3 ± 6.6mm and 42.2 ± 7.2mm. The average discrepancy between the two methods was 4.7mm in twin pregnancies and 5.4mm in singleton. Abdominal cervix measurements correlated with vaginal measurements and were consistently shorter. The discrepancy between abdominal and vaginal measurements did not correlate with singleton or twin pregnancies, maternal body mass index or maternal age. All women with abdominal cervical length >35mm had a corresponding vaginal cervical length >30mm. The use of abdominal measurement of cervical length could be an effective initial tool for cervical length screening in both singleton and twin pregnancies. Cervical length of >35mm could be used as a cut-off value that might make the vaginal measurement redundant in some cases.

Can Transabdominal Scan Predict a Short Cervix by Transvaginal Scan?

Background. To determine whether transabdominal screening can be used to screen women with short cervix on transvaginal scan. Methods. The study was done between 18 and 20 weeks of gestation. Transabdominal scan was done and cervical length was measured. Transvaginal scan was also done and cervical length was measured. An attempt was made to find out whether transabdominal scan be used to predict a cervical length of 25 mm by transvaginal scan. Results. In our study the cut-off for transabdominal scan for detecting a short cervix of 25 mm by transvaginal scan was 29 mm. A transabdominal cervical length of 29 mm could predict a short cervix of 25 mm by transvaginal scan by 100% sensitivity and 92.4% sensitivity. Conclusion. A cut-off of 29 mm by transabdominal scan is very accurate in predicting a short cervix of 25 mm by transvaginal scan.

Comparison of transabdominal and transvaginal ultrasonography for the assessment of cervical length at 16–23 weeks of gestation

The aim of this study was to assess the relationship between transabdominal and transvaginal ultrasonography for the cervical length assessment and to evaluate the predictive value of the transabdominal ultrasonography cervical length assessment for predicting preterm birth. A prospective cohort study was conducted. Transabdominal and transvaginal ultrasonography cervical length assessments were performed in 160 pregnant women between 16 and 23 + 6 weeks of gestation. Transabdominal ultrasonography cervical length assessment was positively correlated with the transvaginal ultrasonography cervical length assessment. Mean ± standard deviation of the cervical length was significantly different between transabdominal and transvaginal ultrasonography (36.4 ± 5.4 vs. 41.2 ± 5.4 mm, p < .001). Transabdominal cervical length was shorter than the transvaginal cervical length with a mean difference of 4.8 mm. The sensitivity, specificity, positive predictive value and negative predictive value for predicting preterm birth when the transabdominal cervical length was ≤35 mm, were 50%, 52.1%, 9.1%, and 91.6%, respectively. In conclusion, transabdominal ultrasonography cervical length assessment is positively correlated with the transvaginal ultrasonography cervical length assessment. Transabdominal cervical length assessment was not a good predictor of preterm birth.

Erken doğum için düşük riskli gebelerde transabdominal servikal uzunluk ölçümünün erken doğum öngörüsündeki önemi

Abstract: The importance of the transabdominal cervical length measurement to predict preterm delivery in low-risk pregnant women for premature birth. Objective: The aim of the present study is to evaluate the efficacy of transabdominal cervical length measurement using ultrasound on predicting preterm birth. Material and Method: The data retrospectively obtained from the records of the patients who were admitted to our department between March 2014 and January 2015 during fetal anatomic survey in 18-24 weeks of pregnancy were retrospectively assessed. Age, obstetric history, delivery week and transabdomial cervical length measurement using ultrasound were obtained form the records. The specificity and sensitivity values were calculated while accepting a cut-off value of 30 mm and 25 mm for cervical length. Results: A total of 142 patients were enrolled. Eleven women had preterm birth, since 131 had term. The mean cervical length was 32.90±8.45 mm in women with preterm birth, and 35.31±7.54 mm in term (p>0.05). Conclusion: The present study suggests that transabdominal cervical length measurement using ultrasound has a limited diagnostic value on the prediction of preterm birth.

Can Transabdominal Cervical Length Measurement Exclude Short Cervix?

This study aims to determine if transabdominal (TA) cervical length may be used to rule out a short cervix on transvaginal (TV) ultrasound. We conducted a prospective cohort study of women undergoing routine anatomic survey at 17 to 23 weeks gestation. TA and TV cervical length measurements were obtained in each patient. A short cervix was defined as TV cervical length < 30 mm. Predictive characteristics were calculated for different cutoff values of TA cervical length. There were 404 patients enrolled, a TA cervical length could not be obtained in 83 women (20.6%) and 318 women had both TA and TV measurements. Of those, 14 (4.4%) had a TV cervical length < 30 mm. TA cervical length measurement ≥ 35 mm excluded the possibility of TV cervical length < 30 mm (negative predictive value, 99.5%; 95% confidence interval [CI], 97.4; 100%). In our cohort, 67.6% (95% CI, 62.2; 72.7%) of TV ultrasounds could have been avoided using a TA cervical length cutoff of ≥ 5 mm. ATA cervical length of at least 35 mm excludes a short cervix of < 30 mm. While TA cervical length screening may not be feasible in 1 in 5 women, it may be used to decrease the burden of universal TV cervical length screening.