The role of the cerebroplacental ratio in predicting pregnancy outcomes at 40-42 gestational weeks: a prospective observational trial.

PURPOSE: The cerebroplacental ratio is a sonographic tool used to predict poor pregnancy outcomes. Data are insufficient regarding its use in postdate pregnancy. We evaluated the cerebroplacental ratio's prediction of unfavorable pregnancy outcomes in women at 40-42 weeks gestation with normal amniotic fluid index. METHODS: This prospective observational study included 101 women with low-risk singleton pregnancy and gestational age > 40 weeks who delivered in a university affiliated hospital during 2020-2021. The middle cerebral artery pulsatility index, the umbilical artery pulsatility index, and the cerebroplacental ratio, which is their quotient, were compared between women with favorable and unfavorable pregnancy outcomes. The latter included: meconium-stained amniotic fluid, cesarean or vacuum-assisted delivery due to pathological cardiotocography (category 2 or 3), 5-min Apgar score < 7, umbilical cord pH < 7.1, neonatal intensive care unit admission, and neonatal death. RESULTS: Fetal Doppler, performed at a median gestational age of 40.3 (40.0-41.6), did not differ between 75 (74.3%) women with favorable obstetrical outcomes and 26 (25.7%) with unfavorable outcomes. In multivariate analysis, advanced maternal age and a history of a cesarean section were correlated with unfavorable outcomes, while Doppler indices were not found to be predictive. Among women at 41-42 weeks' gestation, for those with intrapartum fetal monitor category 2-3 vs. category 1, the mean umbilical artery pulsatility index was higher: 0.92 ± 0.34 vs. 0.71 ± 0.11 (p = 0.044). CONCLUSION: According to the study results, fetal Doppler indices, including the cerebroplacental ratio, are not predictive of unfavorable outcome in women with pregnancies exceeding 40 weeks. Larger prospective studies are needed.

Anterior uterocervical angle: is it an ultrasonographic screening tool that estimates the latent phase duration in post term pregnancies?

OBJECTIVES: In recent years, in addition to cervical length measurement, a new ultrasonographic parameter has been defined as uterocervical angle (UCA), which can be used in the prediction of preterm labor. In this study,we evaluated the place of uterocervical angle in predicting the latent phase duration in postterm pregnancies. MATERIAL AND METHODS: This prospective study consists of 90 pregnant women aged between 18 to 40 years who were hospitalized with a diagnose of late term pregnancy. Pregnant women with a latent phase duration of 1200 minutes or less were defined as Group 1. Patients with latent phase duration over 1200 minutes were defined as Group 2. All patients' age, BMI, smoke, cervical length measurements, uterocervical angle, latent and active phase of labor durations, length of the third stage and delivery types were compared. RESULTS: The UCA median value of group 1 was 120 (94-147), and group 2 was 99 (94-105) (p < 0.001). CL medians of Groups 1 and 2 were 29 (17-43) and 28 (27-41) respectively (p: 0.871). UCA (AUC: 0.917, p < 0.0001) significantly predicted prolonged latent phase duration. Optimal cut off value was obtained at the value of 105 degree (100% sensitivity, 75% specificity) for UCA. Kaplan-Meier survival analysis showed that duration of labor was significantly higher in a group with low UCA (p: 0.013). CONCLUSIONS: UCA can be a successful tool that can be used to predict duration of labor in cases of postterm pregnancies with medical induction.

Reference values for pulsatility index of fetal anterior and posterior cerebral arteries in prolonged pregnancy.

OBJECTIVE: To establish consistent normal reference values for fetal anterior cerebral artery (ACA) and posterior cerebral artery (PCA) pulsatility index (PI) in prolonged pregnancy. METHODS: This prospective cross-sectional observational study included singleton normal prolonged pregnancies into two study groups according to the gestational age: from 40 + 0 to 40 + 6 and from 41 + 0 to 41 + 6 weeks. The PI was assessed in both anatomical segments of ACA (ACA-S1 and ACA-S2) and of PCA (PCA-S1 and PCA-S2) with color Doppler imaging and pulsed Doppler examination, and reference centiles charts were generated. PI values from the two investigated segments of each vessel were also compared. RESULTS: Data were obtained in 771 patients: n = 448 in the 40 + 0 and 40 + 6 weeks group, and n = 323 in the 41 + 0 and 41 + 6 weeks group. A moderate decrease in PI was observed as pregnancy progressed. No differences in PI values were found between the two anatomical segments of ACA and PCA. CONCLUSION: This study provides Doppler reference values for the fetal ACA and PCA PI. It also shows that Doppler examination could be performed indifferently in one of the two anatomical segments of these arteries.

The value of measuring cervical length between 24 and 28 weeks of gestation for predicting the risk of late and post-term pregnancy.

OBJECTIVE: The aim of this study was to investigate the value of measuring cervical length (CL) between 24 and 28 weeks of gestation for predicting the risk of late and post-term pregnancy. METHODS: In this prospective longitudinal study, pregnant women whose CL was measured between 24 and 28 weeks were followed until delivery. The CL was adjusted for confounders and the results are presented using odds ratio and receiver operating characteristic curve (ROC). RESULTS: A total of 874 women met the inclusion criteria. The median value of CL measured between 24 and 28 weeks was 34.0 mm (30.0-38.0 25%, 75% interquartile range). The risk of late and post-term pregnancy was 5.8 times higher in pregnant women with a CL above 35 mm between the 24 and 28 weeks of gestation (95% CI: 2.65-12.94 adjusted OR = 5.8, p < .001). For pregnancies exceeding the 38th week, it was observed that the duration of the gestation increases as CL values increase. CONCLUSIONS: In this study, it has been demonstrated that measuring the CL between 24 and 28 weeks of gestation can predict late and post-term pregnancy. Prolonged pregnancy may cause neonatal and fetal complications and anxiety. CL measurement performed in these weeks can help prepare pregnant women for a possible prolonged pregnancy and cope with prolonged pregnancy anxiety.

Reproducibility of the fetal cerebral vessels assessment in full and late term pregnancies.

Objective: Data concerning feasibility of the fetal cerebral Doppler examination in full term and late term pregnancy is lacking. Our purpose was to perform an evaluation of these arteries with power Doppler ultrasound, calculating the percentage of identification and measurement and the intraobserver reproducibility.Methods: This was a cross sectional study evaluating a population of 578 normally grown fetuses divided according to the week of examination. The first group included fetuses examined at week 40 (N = 323) and the second fetuses examined at week 41 (N = 255). The three major branches of the internal carotid artery (anterior, middle and posterior cerebral arteries, ACA, middle cerebral artery (MCA), posterior cerebral arteries (PCA)) and their anastomosis (A1, A2, P1, P2) were examined with power Doppler ultrasonography by three independent ultrasonographers. The proportion of vessel identified and measured was calculated and the reproducibility among the three operators was investigated.Results: The major arteries at the circle of Willis were fully identified/measured in 65/56 and 62/48% of fetuses at 40 and 41 weeks. The MCA obtained the higher percentage of identification and measurement at both periods (> 80 and >70%). The entire set of anastomosis were less frequently identified/measured at both periods (50/< 50% of cases), especially in the A2 segment. The best agreement was obtained in the MCA and the worst in the PCA-P1 segment.Conclusions: At 40 and 41 weeks, the fetal cerebral vessels, especially the MCA, are suitable for power Doppler evaluation, providing an interesting tool to evaluate fetal hemodynamics in full and late term pregnancy.

Cardiotocography alone vs. cardiotocography with ST segment analysis for intrapartum fetal monitoring in women with late-term pregnancy. A randomized controlled trial.

OBJECTIVES: Randomized studies have obtained conflicting results regarding the usefulness of fetal electrocardiographic (ECG) ST-segment analysis, possibly because these studies included non-homogeneous populations. We designed a study to determine whether this monitoring technique is potentially useful for populations at risk for fetal heart rate alterations during labor, i.e. groups of women who share late-term pregnancy as a risk factor. STUDY DESIGN: This randomized clinical trial recruited women whose pregnancy had lasted more than 290 days. The participants were randomly assigned to continuous fetal cardiotocographic monitoring alone (CTG group) or with fetal ECG ST-segment analysis (ECG-F group). In the CTG group fetal heart rate was interpreted according to guidelines from the National Institute of Child Health and Human Development, whereas in the ECG-F group the tracings were interpreted according the original International Federation of Gynecology and Obstetrics (FIGO) guidelines. The primary outcome measure was neonatal outcome, evaluated as arterial blood pH in neonates after abdominal or vaginal operative delivery indicated because of nonreassuring fetal status. RESULTS: A total of 237 women were randomized, of whom 200 were included in the final analysis (100 in each group). The rate of cesarean delivery was the same in both groups (26%), and the rate of operative delivery due to nonreassuring fetal status did not differ significantly (38% in the CTG group vs. 39% in the ECG-F group). Regarding neonatal outcomes, there was no significant difference between groups in neonatal pH (7.27 [7.23-7.29] and 7.25 [7.21-7.27]). CONCLUSIONS: In a population comprising only late-term pregnancies, fetal ECG monitoring had no benefits for the mother or fetus. Additional studies are needed of protocols for using ST waveform analysis in selected population groups.

The clinical value of maternal and fetal Doppler parameters in low-risk postdates pregnancies - a prospective study.

OBJECTIVE: The objective of this study is to determine the clinical significance of maternal and fetal ultrasound Doppler flow indices in postdates pregnancies. METHODS: This prospective study comprised 120 low-risk pregnant women beyond 40 weeks of gestation. All participants underwent Doppler assessment including of fetal middle cerebral artery (MCA), umbilical, and uterine arteries. Perinatal outcomes were recorded and evaluated for possible associations with Doppler flow values. Adverse perinatal outcomes were defined as umbilical cord arterial pH <7.1, Apgar score <7 at 5 min, neonatal admission to a neonatal intensive care unit, and emergency cesarean section due to abnormal intrapartum cardiotocogram Results: Adverse perinatal outcome rate was 17.5% (n = 21). Doppler indices of umbilical artery, MCA, uterine artery and the cerebroplacental ratio (CPR) did not differ significantly between pregnant women with and without adverse perinatal outcomes. Neonatal birth weight was found to correlate negatively with umbilical artery Doppler indices, including the peak systolic to end diastolic ratio (p = .04), the resistance index (p = .02), and the pulsatility index (p = .01). Doppler values of the uterine artery, MCA and CPR did not correlate with neonatal birth weight. CONCLUSIONS: The contribution of maternal and fetal ultrasound Doppler to the prediction of adverse perinatal outcomes in low-risk postdates pregnancies is low. Hence, performing routine Doppler examination as part of postdates pregnancy assessments is unlikely to yield significant clinical benefit.

[Are ultrasound measurements of the cervical length and fetal head-perineum distance predictive of delivery outcome in post-term pregnancies?]. / Les mesures échographiques de la longueur cervicale et de la hauteur de la présentation fœtale sont-elles prédictives de l'issue d'accouchement chez des patientes à terme ?

OBJECTIVE: Post-term pregnancy is frequently associated with higher fetal and maternal morbidity and mortality. Its management essentially depends on clinical cervical characteristics as evaluated by the Bishop score (BS). However, BS is poorly predictive of the delivery outcome. We sought to demonstrate that ultrasound measurement of cervical length and evaluation of fetal height could predict the outcome in post-term pregnancies. METHODS: A prospective single center study was undertaken between the 21st of January and the 1st of June 2013. Fetal height was measured using a transperineal technique and cervical length was evaluated by a vaginal ultrasound on patients consulting and their term date. C-section rates were considered to be the primary judgment criteria. RESULTS: A total of 136 patients were included. C-section rates in this population was 19%. Fetal height and cervical length were not different between the C-section group and the vaginal delivery group. CONCLUSION: Our study demonstrates that ultrasound measurement of cervical length and fetal height do not show better results than BS in predicting the outcome of post-term pregnancy. Combining these ultrasound measurements has already been suggested in other studies and promising results have been shown. More studies are necessary to further these results.

Risk for girls can be adversely affected post-term due to underestimation of gestational age by ultrasound in the second trimester.

INTRODUCTION: Post-term pregnancies are associated with greater risks for mother and child. Accurate determination of gestational age is necessary for safe care. Female fetuses have been shown to be smaller than males at the time of second-trimester ultrasound (US) examination, leading to underestimation of their age and, potentially, greater impacts of perinatal complications in post-term girls than in post-term boys. The purpose of this study was to investigate the sex ratio of post-term births and differences in perinatal complications (stillbirth, low Apgar score, low birthweight, meconium aspiration and low umbilical artery pH) between post-term boys and girls according to dating method [second-trimester US and last menstrual period (LMP)]. MATERIAL AND METHODS: Data from gestational week ≥39 to delivery of 13 338 singleton pregnancies between 13 February 2006 and 15 January 2014, were collected from the Obstetrix(®) (Siemens Healthcare) medical records system in Dalarna County, Sweden. RESULTS: The neonatal male:female ratio increased with gestational age after week 40, as dated by US, reaching 1.69 in gestational week 42. This ratio remained 1 throughout gestation according to dating by the LMP. Post-term pregnancy increased the risks of meconium aspiration and low Apgar score, with no sex difference observed. CONCLUSIONS: US gestational dating indicated that more boys than girls were born post-term, whereas dating according to LMP revealed no sex difference. These results support the hypothesis that female fetuses are smaller than males, leading to underestimation of their gestational age, at the time of second-trimester US examination.

Association of Second-Trimester Cervical Length With Prolonged Pregnancy.

OBJECTIVE: To estimate whether there is an association between second-trimester cervical length and prolonged pregnancy (defined as delivery at or beyond 41 weeks of gestation). METHODS: This is a cohort study of nulliparous women with a singleton pregnancy who underwent routine cervical length measurement between 18 and 24 weeks of gestation. Women were divided into quartiles by cervical length and the association with prolonged pregnancy was evaluated in bivariable and multivariable analyses. A planned secondary analysis included only women who achieved at least 39 weeks of gestation. RESULTS: During the study period, a total of 9,165 women met inclusion criteria, of whom 1,481 (16.2%) had a prolonged pregnancy. Women in increasing cervical length quartiles were more likely to experience a prolonged pregnancy (12.9%, 15.8%, 17.1%, 18.6%, P<.001). This association remained significant when controlling for possible confounding variables. An analysis confined to women who achieved at least 39 weeks of gestation was consistent with the overall analysis. CONCLUSION: Increasing second-trimester cervical length is associated with an increased likelihood of having a prolonged pregnancy in nulliparous women. LEVEL OF EVIDENCE: II.

[Ultrasonographic and clinical methods in the management of prolonged pregnancy]. / Confronto tra metodiche cliniche e strumentali nella gestione della gravidanza protratta.

AIM: The aim of this study was to evaluate the role of Bishop score, sonographic measurements of uterine cervical length and maternal characteristics, as predictors of spontaneous onset of labor within 24 hours, as well as response to induction in prolonged pregnancies. METHODS: Pregnancies with gestational age over 280 days were followed as outpatient. Patients were included in the study if spontaneous delivery occurred between 286 and 295 days of gestation, or in pregnancies with gestational age of 291-293 days who required labor induction. Data about Bishop score, ultrasonographic cervical characteristics (length, funneling, volume) and maternal features (parity, body mass index and age) registered at the last control immediately before the delivery were retrieved from clinical charts. RESULTS: Data from 195 patients were available. Bishop score and, in particular, ultrasonographic cervical length can predict the spontaneous onset of labor with a positive predictive value (PPV) of 22% and 44%, respectively in 24 hours. On the other hands, in patients requiring labor induction, parity and ultrasonographic cervical length remained the only predictive parameters with a PPV of 39% and 42%, respectively. In term of predictive performance, the value of 30 mm was identified as the best cut-off value for the ultrasonographic cervical length (specificity 59% and sensitivity 69%). CONCLUSION: In prolonged pregnancies, Bishop score and ultrasonographic cervical length were shown to be relevant in the prediction of spontaneous onset of labor, while in patients who required labor induction, ultrasonographic cervical length represented the only clinic parameter predicting the onset of labor.

Bishop score versus ultrasound of the cervix before induction of labor for prolonged pregnancy: which one is better for prediction of cesarean delivery.

OBJECTIVES: To find an effective way to predict Cesarean section (CS) before induction of labor. METHODS: Nulliparous women at ≥ 41 weeks of pregnancy were enrolled in the study. Bishop score (BS), cervical length (CL), posterior cervical angle (PCA), quantification of the cervical stromal echogenicity by tissue histograms and opening of the internal cervical os (funnelling) were recorded. The vaginal delivery and CS groups were then compared in terms of the clinical and ultrasonographic cervical findings. RESULTS: BS, CL, PCA and funnelling were the significant predictors of CS, whereas no such relationship existed for the quantitative echogenicity of the cervical stroma. Although the difference was not statistically significant, the area under the curve was higher for the BS than that for sonographic CL and PCA in the prediction of all CSs. The best cut-off values to predict CS for BS, CL and PCA were <5, >27 mm and <98°, respectively. Combination of all three parameters had a sensitivity of 83.3%, specificity of 100%, positive predictive value of 100% and a negative predictive value of 82% for the prediction of CS. CONCLUSIONS: In nulliparous women with prolonged pregnancy, the BS predicts the need for CS better than the ultrasonographic assessment of the cervix.

Clinical efficacy of cervical length and volume for prediction of labor onset in VBAC candidates.

BACKGROUND: The purpose of this research is to discover whether measurement of cervical length and cervical volume at term is helpful in predicting the onset of labor in VBAC candidates. METHODS: Transvaginal sonographic evaluations of the cervixes of pregnant women who desired to undergo VBAC were performed between 36 - 40 weeks gestation. Clinical information such as labor onset time, gestational age at delivery and delivery mode was gathered from medical records. RESULTS: A total of 514 pregnant women participated in this study. Cervical length was significantly longer in the group that delivered 7 days or more after measurement than in the group that delivered within 7 days of measurement (43±0.77 cm vs. 2.99±0.72 cm, p< 0.001). Cervical volume was significantly larger in the group that delivered at and after 7 days than in the group that delivered within 7 days (29.21±11.62 cm(3) vs. 34.07±13.41 cm(3), p=0.014). The cervical length ROC curve was significantly more predictive than the cervical volume ROC curve (AUC: 0.711 vs 0.594, p= 0.001). There were no significant differences between the combined cervical length/volume ROC curve and the cervical length ROC curve alone (p= 0.565). The AUC of the cervical length ROC curve to predict postterm pregnancy was 0.729. CONCLUSION: Measuring cervical length is helpful in predicting the onset of spontaneous labor within 7 days and posterm delivery in VBAC candidates.

Rate of postdates induction using first-trimester ultrasound to determine estimated due date: Wellington Regional Hospital audit.

AIM: The aim of this audit was to examine the effect of using first-trimester (<14 weeks) ultrasound scan to determine EDD (US EDD) on the rate of induction for postdates pregnancies at Wellington Regional Hospital. METHODS: Women with singleton live pregnancies who had postdates (≥41 weeks) induction at Wellington Hospital during January 2009 to November 2009 were identified using a computerised database [Perinatal Information Management System (PIMS)]. The first-trimester ultrasound images and reports for these women were retrieved and reviewed by a specialist in obstetric ultrasound. Only ultrasound studies that had technically satisfactory images at <14 weeks were included. RESULTS: A total of 329 women with a singleton live pregnancy were induced for postdates during the study period. Of these women, 50 (15.2%) were not ≥41 weeks on PIMS EDD and therefore on the best available evidence should not have been induced for being postdates. Of the remaining 279 women, 158 had first-trimester scans available for review. Forty-three of 158 (27%) were <41 weeks when US EDD was used. CONCLUSIONS: The rate of postdates inductions at Wellington NRH could be decreased by 38% if induction was limited to women over 41-week gestation and by using US EDD as opposed to last menstrual period EDD. The use of early gestational scans (<14 weeks) to estimate EDD lowers the rate of postdates induction. This is very similar to the observed findings in literature.

Biochemical and biophysical predictors of the response to the induction of labor in nulliparous postterm pregnancy.

OBJECTIVE: The objective of the study was to evaluate the clinical, sonographic, and hormonal variables that influence the success of labor induction in nulliparous postterm pregnancies. STUDY DESIGN: Fifty nulliparous women with a single postterm pregnancy receiving a slow-release prostaglandin estradiol pessary were prospectively enrolled, and clinical characteristics were analyzed in relation to success of induction of labor. Clinical, sonographic, and hormonal variables were analyzed by univariate statistical analysis and multivariate logistic regression for the prediction of successful induction. RESULTS: The group of patients delivering within 24 hours differed significantly from the remaining patients by higher Bishop scores, body mass indices, estradiol serum concentrations, estriol to estradiol ratios, and shorter cervices. The combination of cervical length and estriol to estradiol ratio achieved a sensitivity of 100% (95% confidence interval, 71.3-100%) and a specificity of 94.1% (95% confidence interval, 80.3-99.1%). CONCLUSION: Cervical length and the estriol to estradiol ratio represent good predictive indicators of the response to the induction of labor in postterm pregnancies.

[Elastography in the examination of the uterine cervix before labor induction]. / Zastosowanie elastografii w ocenie szyjki macicy przed indukcja porodu.

OBJECTIVE: The authors of the following work have attempted to assess the usefulness of elastography in the uterine cervix examination before induction of labor MATERIAL AND METHODS: Sixteen pregnant women, hospitalized at the Department of Obstetrics and prepared for labor induction due to post-term pregnancy or diabetes, were examined. Differences in stiffness of anterior and posterior cervical wall was assessed by means of elastography. The results were compared to Bishop Score and correlation with reaction to Oxytocin infusion was calculated. RESULTS: There was no statistically significant correlation between cervical consistence assessed by vaginal examination and by elastography. Correlation between the Bishop Score and cervical consistence assessed manually was not statistically significant. Authors found strong correlation between elastography results and success of labor induction. CONCLUSIONS: Cervical assessment by means of elastography predicts the results of labor induction with Oxytocin better than vaginal examination.

[Dopplerometry at prolonged pregnancy].

Prolonged pregnancy, associated with low amniotic fluid is a reason for the increase of fetal mortality and morbidity. There is no a define test at prolonged pregnancy which can determine which pregnancy are at a risk for adverse outcome and complications. Dopplerometry as a noninvasive method for examination of blood circulation, and especially a. cerebri media and a. umbilicalis can be used for the prediction of the outcome of prolonged pregnancy.

Ultrasound in labor and delivery.

Ultrasound may play an important role in the management of labor and delivery. Induction of labor is a common obstetric intervention, performed in about 20% of pregnancies. Pre-induction cervical length, measured by transvaginal sonography, has been shown to have a significant association with the induction-to-delivery interval and the risk for cesarean section. In the management of labor there is extensive evidence that digital pelvic examination does not provide accurate assessment of the position and descend of the fetal head both during the first but also in the second stage of labor. Several recent studies using both two- and three-dimensional ultrasound have now described objective measures of progression of the fetal head during labor. In instrumental deliveries an important determinant of a successful and safe use of vacuum and forceps is the correct determination of the fetal head position and appropriate application of the instrument. However, ultrasound studies have shown that digital examination before instrumental delivery fails to identify the correct fetal position in a high proportion of cases. The use of ultrasound is of crucial importance in performing a safe operative delivery and can help in the prediction of whether a vaginal delivery would be successful.