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- Kuusela, Pihla, et al.
(författare)
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Second trimester cervical length measurements with transvaginal ultrasound : a prospective observational agreement and reliability study
- 2020
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Ingår i: Acta Obstetricia et Gynecologica Scandinavica. - : John Wiley & Sons. - 0001-6349 .- 1600-0412. ; 99:11, s. 1476-1485
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Universal screening for preterm delivery by adding transvaginal ultrasound measurement of cervical length to routine second trimester ultrasound has been proposed. The aim is to estimate inter- and intra-observer agreement and reliability of second trimester transvaginal ultrasound measurements of cervical length performed by specially trained midwife sonographers.MATERIAL AND METHODS: This is a prospective reliability and agreement study performed in seven Swedish ultrasound centers. In total, 18 midwife sonographers specially trained to perform ultrasound measurements of cervical length and 286 women in the second trimester were included. In each center two midwife sonographers measured cervical length a few minutes apart in the same woman, the number of women examined per examiner pair varying between 24 and 30 (LIVE study). Sixteen midwife sonographers measured cervical length twice ≥2 months apart on 93 video-clips (CLIPS study). The main outcome measures were mean difference, limits of agreement, intra-class correlation coefficient, intra-individual standard deviation, repeatability, Cohen´s kappa, and Fleiss kappa.RESULTS: The limits of agreement and intra-class correlation coefficient of the best examiner pair in the LIVE study were -4.06 to 4.72 mm and 0.91, those of the poorest were -11.11 to 11.39 mm and 0.31. In the CLIPS study, median (range) intra-individual standard deviation was 2.14 mm (1.40 to 3.46), repeatability 5.93 mm (3.88 to 9.58), intra-class correlation coefficient 0.84 (0.66 to 0.94). Median (range) inter-observer agreement for cervical length ≤25 mm in the CLIPS study was 94.6% (84.9% to 98.9%) and Cohen´s kappa 0.56 (0.12 to 0.92), median (range) intra-observer agreement was 95.2% (87.1% to 98.9%) and Cohen´s kappa 0.68 (0.27 to 0.93).CONCLUSIONS: Agreement and reliability of cervical length measurements differed substantially between examiner pairs and examiners. If cervical length measurements are used to guide management there is potential for both over- and under-treatment. Uniform training and rigorous supervision and quality control are advised.
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- Kuusela, Pihla, et al.
(författare)
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Second trimester transvaginal ultrasound measurement of cervical length for prediction of preterm birth : a blinded prospective multicentre diagnostic accuracy study
- 2021
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Ingår i: British Journal of Obstetrics and Gynecology. - : Wiley-Blackwell Publishing Inc.. - 1470-0328 .- 1471-0528. ; 128:2, s. 195-206
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To estimate the diagnostic performance of sonographic cervical length for prediction of preterm birth (PTB).DESIGN: Prospective observational multicentre study.SETTING: Seven Swedish ultrasound centres.SAMPLE: 11456 asymptomatic women with a singleton pregnancy.METHODS: Cervical length was measured with transvaginal ultrasound at 18 to 20 weeks (Cx1) and at 21 to 23 weeks (Cx2; optional). Staff and participants were blinded to results.MAIN OUTCOME MEASURES: Area under receiver operating characteristic curve (AUC), sensitivity, specificity, positive and negative predictive values (PPV, NPV), positive and negative likelihood ratios (LR+, LR-), number of false positive results per true positive result (FP/TP), number needed to screen to detect one PTB (NNS), prevalence of "short" cervix.RESULTS: Spontaneous PTB (sPTB) <33 weeks occurred in 56/11072 (0.5%) women in the Cx1 population (89% white ethnicity) and in 26/6288 (0.4%) in the Cx2 population (92% white ethnicity). The discriminative ability of shortest endocervical length was better the earlier the sPTB occurred and better at Cx2 than at Cx1 (AUC to predict sPTB <33 weeks 0.76 versus 0.65, difference in AUC 0.11, 95% CI 0.01 to 0.23). At Cx2, shortest endocervical length ≤25 mm (prevalence 4.4%) predicted sPTB <33 weeks with sensitivity 38.5% (10/26), specificity 95.8% (5998/6262), PPV 3.6% (10/274), NPV 99.7% (5988/6014), LR+ 9.1, LR- 0.64, 26 FP/TP, 629 NNS.CONCLUSION: Second trimester sonographic cervical length can identify women at high risk of sPTB. In a population of mainly white women and low prevalence of sPTB its diagnostic performance is at best moderate.
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- Wikström, Tove, et al.
(författare)
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Effect of second-trimester sonographic cervical length on the risk of spontaneous preterm delivery in different risk groups : a prospective observational multicenter study
- 2021
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Ingår i: Acta Obstetricia et Gynecologica Scandinavica. - : John Wiley & Sons. - 0001-6349 .- 1600-0412. ; 100:9, s. 1644-1655
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: The aim of the study is to compare the effect of cervical length measured with transvaginal ultrasound in the second trimester on the risk of spontaneous preterm delivery between different risk groups of asymptomatic women with a singleton pregnancy.MATERIAL AND METHODS: This is a pre-planned exploratory analysis of the CERVIX study, a prospective blinded multicenter diagnostic accuracy study. Asymptomatic women with a singleton pregnancy were consecutively recruited at their second-trimester routine ultrasound examination at seven Swedish ultrasound centers. Cervical length was measured with transvaginal ultrasound at 18-20 weeks (Cx1; n=11 072) and 21-23 weeks (Cx2, optional; n=6288). The effect of cervical length on the risk of spontaneous preterm delivery and its discriminative ability was compared between women with: i. previous spontaneous preterm delivery, late miscarriage or cervical conization (high-risk group; n=1045); ii. nulliparae without risk factors (n=5173); iii. parae without risk factors (n=4740). Women with previous indicated preterm delivery were excluded (n=114). Main outcome measures were: effect of cervical length on the risk of spontaneous preterm delivery expressed as odds ratio per 5 mm decrease in cervical length with interaction analysis using logistic regression to test if the effect differed between groups, area under the receiver operating characteristic curve (AUC), sensitivity, specificity, number needed to screen to detect one spontaneous preterm delivery.RESULTS: The effect of cervical length at Cx2 on the risk of spontaneous preterm delivery <33 weeks was similar in all groups (odds ratios 2.26 to 2.58, interaction P-value 0.91). The discriminative ability at Cx2 was superior to that at Cx1 and was similar in all groups (AUC 0.69 to 0.76). Cervical length ≤25 mm at Cx2 identified 57% of spontaneous preterm deliveries <33 weeks in the high-risk group with number needed to screen 161. The number needed to screen for groups ii and iii were 1018 and 843.CONCLUSIONS: The effect of cervical length at 21-23 weeks on the risk of spontaneous preterm delivery <33 weeks is similar in high- and low-risk pregnancies. The differences in number needed to screen should be considered before implementing a screening program.
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