In women presenting with threatened preterm labor, both fetal fibronectin and sonographic measurement of cervical length have been shown to distinguish between true and false labor. The aim of this study was to determine whether the combination of both tests provides a better prediction than the individual tests alone.

Transvaginal ultrasound scanning of cervical length at approximately 20 weeks of gestation in women attending for routine antenatal care is useful for predicting the likelihood of spontaneous early preterm birth. The risk of early birth increases exponentially with decreasing cervical length in both singleton and multiple pregnancies. In such women, individualisation of risk would lead to rationalisation of antenatal care, including frequency of visits, patient education in recognising and reporting symptoms of spontaneous preterm labour and timely administration of steroids. It is also possible that in women identified as being at high risk, the rate of preterm birth might be reduced by the prophylactic use of progesterone. In women presenting with threatened spontaneous preterm labour, transvaginal measurement of cervical length provides a useful distinction between those who are likely to deliver within the subsequent 7 days and those who are not. Since only 10–20% of such women are in true spontaneous preterm labour, the cervical length measurement in rational care can avoid the current practice of hospitalisation and administration of steroids and tocolytics to all. This article reviews the evidence in support of the clinical introduction of transvaginal sonography for both the prediction and management of spontaneous preterm labour.

RESUMENObjetivo: Determinar el Likelihood Ratio (LR)para trisomia 21 en fetos con regurgitaciontricuspidea a la ecografia efectuada entre las 11 y13 + 6 semanas. Metodos: Ecocardiografia fetalfue realizada por cardiologos infantiles en 742embarazos unicos entre las 11 y 13+ 6 semanas.Se utilizo Doppler pulsado para evaluar la presen-cia de regurgitacion tricuspidea (RT), exigiendopara su diagnostico que la onda obtenida ocuparaal menos la mitad del sistole cardiaco y alcanzarauna velocidad superior a 80 cm/s. Se midio lalongitud cefalo nalgas (LCN) y el grosor de latranslucidez nucal (TN) y se registro la presenciade cualquier anomalia cardiaca. Se efectuo segui-miento del embarazo para determinar la presenciade anomalias cromosomicas. Se calculo LR paratrisomia 21 en fetos con y sin regurgitacion tricus-pidea. Resultados: La valvula tricuspidea fue sa-tisfactoriamente examinada en 718 (96,8%) casos.RT estaba presente en 39 (8,5%) de los 458 fetoscromosomicamente normales, en 82 (65,1%) delos 126 con trisomia 21, en 44 (53%) de los 83con trisomia 18 o 13, y en 11 (21,6%) de los 51con otros defectos cromosomicos. La prevalenciade RT estaba tambien asociada con LCN, deltaTN y la presencia de anomalias cardiacas. El ana-lisis de regresion logistica, independiente de lapresencia de defectos cardiacos, demostro que enlos fetos cromosomicamente normales, una pre-diccion independiente y significativa de la probabi-lidad de regurgitacion tricuspidea era aportada porel delta TN (odds ratio 1,26; 95% CI, 1,34-1,41; p<0,0001), mientras que en fetos con trisomia 21 eraproporcionada por LCN (odds ratio 0,94; 95% CI,0,89-0,99; P=0,021). El LR para trisomia 21 segunRT, fue obtenido dividiendo la probabilidad entrisomia 21 por la probabilidad en fetos normales.En fetos cromosomicamente normales, la preva-lencia de RT en fetos con defectos cardiacos fue46,9% y 5,6% en aquellos sin defectos cardiacos,y el LR de RT para anomalias cardiacas fue 8,4.Conclusion: Entre las 11 y 13 + 6 semanas, hayuna alta asociacion entre RT y trisomia 21, asicomo de otros defectos cromosomicos. La preva-lencia de RT aumenta con el grosor de TN y essustancialmente mayor en aquellos fetos con ano-malias cardiacas.ANALISIS DE LA INVESTIGACIONA. Relevancia clinica de la investigacionEn pacientes con translucidez nucal (TN) au-mentada entre las 11 y 13 + 6 semanas, la pre-sencia de regurgitacion tricuspidea ?es un buenpredictor del riesgo de trisomia 21?Escenario clinico: TN aumentada esta asocia-da con anomalias cromosomicas y una variedadde malformaciones fetales y sindromes geneticos(2, 3). En poblaciones de alto riesgo de cromoso-mopatias (TN aumentada) se ha reportado la pre-sencia de regurgitacion tricuspidea (RT) en 59%de fetos con Sindrome de Down y 8,8% de losnormales (4). Sin embargo, su utilidad y aplica-cion en modificar el riesgo para trisomia 21 serelaciona a su dependencia o independencia deotros factores de riesgo, en particular del grosorde TN.

Objective To determine the likelihood ratio for trisomy 21 in fetuses with tricuspid regurgitation at the 11 to 13 + 6-week scan. Methods Fetal echocardiography was carried out by specialist pediatric cardiologists in 742 singleton pregnancies at 11 to 13 + 6 weeks' gestation and pulsed wave Doppler was used to ascertain the presence or absence of tricuspid regurgitation. To avoid confusion with other adjacent signals, a strict definition of tricuspid regurgitation was used, in that it had to occupy at least half of systole and reach a velocity of over 80 cm/s. The fetal crown-rump length (CRL) and the nuchal translucency (NT) thickness were measured and the presence of any congenital heart abnormality noted. Follow-up of the pregnancy was carried out to determine the presence of chromosomal abnormalities. The likelihood ratio for trisomy 21 in fetuses with and without tricuspid regurgitation was determined. Results The tricuspid valve was successfully examined in 718 (96.8%) cases. Tricuspid regurgitation was present in 39 (8.5%) of the 458 chromosomally normal fetuses, in 82 (65.1%) of the 126 with trisomy 21, in 44 (53.0%) of the 83 with trisomy 18 or 13, and in 11 (21.6%)of the 51 with other chromosomal defects. The prevalence of tricuspid regurgitation was also associated with fetal CRL, delta NT and the presence of cardiac defects. Logistic regression analysis, irrespective of cardiac defects, demonstrated that in the chromosomally normal fetuses significant independent prediction of the likelihood of tricuspid regurgitation was provided by fetal delta NT (odds ratio (OR), 1.26; 95% CI, 1.34-1.41; P < 0.0001), while in trisomy 21 fetuses prediction was provided by CRL (OR, 0.94; 95% CI, 0.89-0.99; P = 0.021). The likelihood ratio for trisomy 21 for tricuspid regurgitation was derived by dividing the likelihood in trisomy 21 by that in normal fetuses. In the chromosomally normal fetuses, the prevalence of tricuspid regurgitation in those with cardiac defects was 46.9% and 5.6% in those without cardiac defects, and the likelihood ratio of tricuspid regurgitation for cardiac defects was 8.4. Conclusion At 11 to 13 + 6 weeks' gestation, there is a high association between tricuspid regurgitation and trisomy 21, as well as other chromosomal defects. The prevalence of tricuspid regurgitation increases with fetal NT thickness and is substantially higher in those with, than those without, a cardiac defect. Copyright (c) 2005 ISUOG.

Objectives To predict when delivery will occur, within 48 h and 7 days of presentation and before 35 weeks' gestation in women presenting with threatened preterm labor.Methods Sonograpbic measurement of cervical length was carried out in 510 women with singleton pregnancies presenting with threatened preterm labor and intact membranes at 24 to 33 + 6 weeks of gestation. The measurement was not taken into account in the subsequent management of the pregnancies. The outcome measures were delivery within 48 h and 7 days of presentation and delivery before 35 weeks.Results The median gestation at presentation was 30 + 1 (range, 24 to 33 + 6) weeks and the median cervical length was 25 (range, 1-51) mm. Delivery within 48 h of presentation occurred in 21 (4.1%) cases, delivery within 7 days occurred in 43 (8.4%) and delivery before 35 weeks occurred in 76 (14.9%). Logistic regression analysis demonstrated that the only significant independent predictor of deliver), within 48 h was cervical length (odds ratio (OR), 0.73; 95% CI, 0.65-0.81) and for deliver), within 7 days the independent predictors were cervical length (OR, 0.69; 95% CI, 0.63-0.76) and vaginal bleeding (OR, 19.42; 95% CI, 3.87-97.4). In the subgroup of women who did not deliver within 7 days of presentation, the incidence of delivery before 35 weeks was 7.1% (33 of 467) and the only significant independent predictor of such deliver), was cervical length (OR, 0.92; 95% CI, 0.88-0.96, P < 0.0001). There was no significant independent contribution to an), of the outcome measures from ethnic group, maternal age, gestational age, body mass index, parity, cigarette smoking or use of tocolytics.Conclusions In women with threatened preterm labor sonograpbic measurement of cervical length helps to distinguish between true and false labor and to predict early preterm delivery. Copyright (c) 2005 ISUOG.

Objective To determine whether sonographic measurement of cervical length in twin pregnancies presenting with threatened preterm labor helps distinguish between true and false labor.Methods In 87 women with twin pregnancies presenting with regular and painful uterine contractions at 24-36 (median, 30) weeks of gestation, cervical length was measured by transvaginal ultrasound. Women presenting in active labor, defined by the presence of cervical dilation of 3 cm or more, with ruptured membranes and those who underwent a prior or subsequent cervical cerclage, were excluded from the study. The clinical management was determined by the attending obstetrician without taking into account the cervical length. Primary outcome of the study was delivery within 7 days of presentation.Results Delivery within 7 days of presentation occurred in 19/87 (22%) pregnancies and this was inversely related to cervical length, decreasing from 80% (4/5) at 1-5 mm, to 46% (6/13) at 6-10 mm, 29% (4/14) at 11 - 15 mm, 21% (4/19) at 16-20 mm, 7% (1/15) at 21-25 mm and 0% (0/21) at > 25 mm. Logistic regression analysis demonstrated that significant independent contribution in the prediction of delivery within 7 days was provided by cervical length (odds ratio (OR)= 0.78 95% CI 0.68-0.89, P < 0.001) and use of tocolytics (OR = 0.13, 95% CI 0.02-0.76, P = 0.024), with no significant contribution from gestation at presentation, chorionicity, ethnic origin, maternal age, body mass index, parity, previous history of preterm delivery, cigarette smoking, contraction frequency, vaginal bleeding or the administration of antibiotics or steroids.Conclusion In women with twin pregnancies presenting with threatened preterm labor, sonographic measurement of cervical length helps distinguish between those who deliver within 7 days and those who do not. Copyright (C) 2004 ISUOG. Published by John Wiley & Sons, Ltd.

To investigate the interobserver agreement on the intrapartum ultrasonographic definition of the fetal occipital position.

Objective To determine whether sonographic measurement of cervical length in pregnancies complicated by preterm prelabor amniorrhexis helps distinguish between those women who deliver within 7 days and those who do not.Methods In 101 women with singleton pregnancies presenting with preterm prelabor amniorrhexis at 24-36 (median, 32) weeks of gestation cervical length was measured by transvaginal ultrasound. Exclusion criteria were active labor defined by the presence of cervical dilatation of greater than or equal to 3 cm and iatrogenic delivery for fetal or maternal indication when not in active labor. The clinical management was determined by the attending obstetrician. The primary outcome of the study was delivery within 7 days of presentation.Results Delivery within 7 days of presentation occurred in 58/101 (57%) pregnancies. Logistic regression analysis demonstrated that significant independent contribution in the prediction of delivery within 7 days was provided by cervical length (odds ratio (OR) = 0.91, 95% CI 0.86-0.96, P = 0.001), gestation at presentation (OR = 1.35, 95% CI 1.14-1.59, P = 0.001) and presence of contractions at presentation (OR = 3.07, 95% CI 1.05-8.92, P = 0.039) with no significant independent contribution from ethnic origin, maternal age, body mass index, parity, previous history of preterm delivery, cigarette smoking, vaginal bleeding or the administration of tocolytics, antibiotics or steroids.Conclusion In women with preterm prelabor amniorrhexis prediction of delivery within 7 days is provided by cervical length, gestation and presence of contractions at presentation. Copyright (C) 2004 ISUOG. Published by John Wiley Sons, Ltd.

Objective In a previous study conducted in the UK we demonstrated that only 8% of women with threatened preterm labor deliver within 7 days. Furthermore, delivery within 7 days occurred in less than 1% of women presenting with a sonographically measured cervical length greater than or equal to15 mm, compared to 37% in those with cervical length <15 mm. In this study we investigate the potential value of cervical length in the prediction of outcome of threatened preterm labor in a South African population.Methods We examined 63 women with singleton pregnancies presenting with regular and painful uterine contractions at 24-36 (mean, 31) weeks of gestation. Women in active labor, defined by the presence of cervical dilatation >= 3 cm, and those with ruptured membranes were excluded. On admission to the hospital a transvaginal scan was performed to measure the cervical length. The subsequent management was determined by the attending obstetrician. The primary outcome was delivery within 7 days of presentation.Results Delivery within 7 days of presentation occurred in 20/63 (32%) pregnancies, including 20 of the 30 (67%) cases with cervical length <15 mm and none of the 33 cases with cervical length greater than or equal to15 mm. Logistic regression analysis demonstrated that the only significant contributor in the prediction of delivery within 7 days was cervical length (odds ratio 0.67; 95% CI 0.54-0.85; P = 0.001) with no significant independent contribution from maternal age, gestational age, body mass index, parity, use of antibiotics, previous history of preterm delivery, cigarette smoking, contraction frequency or use of tocolytics.Conclusion In this South African population, which bad a high incidence of delivery within 7 days of Presentation with threatened preterm labor, sonographic measurement of cervical length is equally effective as in a lower-risk population in distinguishing between true and false labor. Copyright (C) 2004 ISUOG. Published by John Wiley Sons, Ltd.

Objective To investigate if occiput posterior delivery is the consequence of persistence of an initial occiput posterior position or malrotation from an initial occiput anterior or transverse position.Methods This was a cross-sectional study involving transabdominal sonography to determine fetal occipital position in 918 singleton pregnancies with cephalic presentation in active labor at 37-42 weeks of gestation. The relationship between occipital position in labor and at delivery was examined.Results The occiput was posterior in 33.0% (149/452), 33.9% (101/298) and 19.0% (32/168) of fetuses at the respective cervical dilatations of 3-5, 6-9 and 10 cm and this persisted at delivery in 21.5% (32/149), 31.7% (32/101) and 43.8% (14/32) of cases. In 70% (32/46), 91% (32/35) and 100% (14/14) of occiput posterior deliveries there was persistence from this position at 3-5, 6-9 and 10 cm of cervical dilation.Conclusions The majority of occiput posterior positions during labor rotate to the anterior position even at 10 cm of cervical dilatation. However, the vast majority of occiput posterior positions at delivery are a consequence of persistence of this position during labor rather than malrotation from an initial occiput anterior or transverse position. Copyright (C) 2004 ISUOG. Published by John Wiley Sons, Ltd.

30% aller Frühgeburten folgen auf einen vorzeitigem Blasensprung. Wir untersuchten, ob eine sonographische Zervixlängenmessung bei Frauen mit vorzeitigem Blasensprung eine Identifizierung der Frauen mit einem hohen Risiko einer Frühgeburt innerhalb der nächsten sieben Tage ermöglicht.

More than 70% of women presenting with threatened preterm labor do not progress to active labor and delivery. The aim of this study was to investigate the hypothesis that in women with threatened preterm labor, sonographic measurement of cervical length helps distinguish between true and false labor.

Objective To investigate the accuracy of intrapartum transvaginal digital examination in defining the position of the fetal bead before instrumental delivery.Patients and Methods In 64 singleton pregnancies undergoing instrumental delivery the fetal bead position was determined by transvaginal digital examination by the attending obstetrician. Immediately after or before the clinical examination, the fetal bead position was determined by transabdominal ultrasound by a trained sonographer who was not aware of the clinical findings. The digital examination was considered to be correct if the fetal bead position was within +/- 45degrees of the ultrasound finding. The accuracy of the digital examination was examined in relation to maternal and fetal characteristics.Results Digital examination failed to define the correct fetal bead position in 17 (26.6%) cases. In 12 of 17 (70.6%) errors the difference was greater than or equal to90degrees and in five (29.4%) the difference was between 45degrees and 90degrees. The accuracy of vaginal digital examination was 83% for occiput-anterior and 54% for occiput-lateral + occiput-posterior positions. Logistic regression analysis demonstrated significant independent contributions in explaining the variance in the accuracy of vaginal examination for the station of the fetal bead, the position of the fetal head and the experience of the examining obstetrician.Conclusions Digital examination during instrumental delivery fails to identify the correct fetal bead position in about one quarter of cases. Copyright (C) 2003 ISUOG. Published by John Wiley Sons, Ltd.

Objective: To investigate the accuracy of intrapartum transvaginal digital examination in defining the position of the fetal head. Patients and methods: In 496 singleton pregnancies in labor at term, the fetal head position was determined by routine transvaginal digital examination by the attending midwife or obstetrician. Immediately before or after the clinical examination, the fetal head position was determined using transabdominal ultrasound by an appropriately trained sonographer who was not aware of the clinical findings. The digital examination was considered to be correct if the fetal head position was within 45° of the ultrasound finding. The accuracy of the digital examination was examined in relation to maternal characteristics and the progress of labor. Results: The position of the fetal head was determined by ultrasound examination in all 496 cases examined. Digital examination failed to define the fetal head position in 166 (33.5%) cases and, in 330 cases where the position was determined, the findings of the digital and sonographic examinations were in agreement in only 163 (49.4%) cases. The rate of correct identification of the fetal position by digital examination increased with cervical dilatation, from 20.5% at 3–4 cm to 44.2% at 8–10 cm, and was higher if the examination was carried out by an obstetrician than a midwife (50% versus 30%) and if there was absence rather than presence of caput (33% versus 25%). Conclusions: Routine digital examination during labor fails to identify the correct fetal position in the majority of cases.