Ecografía transvaginal en preinducción de parto: predicción de parto vaginal en gestantes con cesárea anterior / Transvaginal ultrasound in induction of labour: predicting vaginal delivery in patients with a prior cesarean section

Resumen Objetivo: Determinar qué mediciones de la ecografía transvaginal efectuada en el momento de la inducción actúan como predictoras de éxito de parto vaginal en embarazadas con cesárea anterior. La valoración cervical previa a la inducción del parto se lleva a cabo mediante tacto vaginal y estimación del índice de Bishop. Se trata de un diagnóstico subjetivo y sujeto a variabilidad interobservador, por lo que es necesario encontrar un sistema alternativo objetivo y con mínima variabilidad interindividual. Materiales y métodos: Estudio analítico, observacional y prospectivo al que se incluyeron pacientes con antecedente de cesárea, previamente inducidas con sonda de doble balón. Antes de la finalización del embarazo a todas las pacientes se les tomó una ecografía transvaginal para determinar: la longitud cervical, ángulo cervical posterior, grosor y dilatación cervical. Se obtuvieron los informes de la preinducción, parto y puerperio. Resultados: Se estudiaron 35 pacientes y la tasa de parto vaginal fue de 52%. Hubo diferencias significativas en la medición de la longitud cervical entre el grupo de parto vaginal y cesárea, en estas últimas fue más larga (26.8 vs 33.5 mm; p = 0.036). No se encontraron diferencias en el ángulo cervical posterior, dilatación o grosor cervical. Conclusiones: La longitud cervical se perfila como variable predictora de parto vaginal en la preinducción de embarazadas con cesárea anterior; existen diferencias significativas entre el grupo de embarazadas con parto vaginal luego de una cesárea previa (26.8 mm) y el grupo de pacientes con segunda cesárea (33.5 mm).

Abstract Objective: The aim of this study was to determine what circumstances during transvaginal ultrasound predict vaginal delivery in labour induction of patients with a previous caesarean section. Several studies have confirmed that the accuracy of the Bishop's score in predicting the outcome of induction of labour is poor, due to the subjectivity of digital examination, which is also influenced by interobserver variability. That is why it is necesary to find an alternative score which provides objectiveness and minimum interobserver differencies. Materials and methods: An observational prospective and analytic study was designed and 35 patients were included. All of them had a previous caesarean section and underwent cervical induction with a double balloon device. Transvaginal ultrasound was run in all the cases, regarding cervical length, posterior cervical angle, thickness and cervical dilation. Moreover, data from delivery and postpartum were recorded. Results: Vaginal delivery rate was 51.6%. Significative diferencies between cervical lenght in patients who delivered vaginally and those with a second cesarean section were found (26.8mm versus 33.5mm, p = 0.036). No differencies were found between posterior cervical angle measures, nor cervical dilation or cervical thickness. Conclusions: Cervical length is outlined as a predictive variable of vaginal delivery in preinduction of patients with a previous cesarean section. It has been demostrated that this measurement is significatively shorter in patients having a vaginal delivery (26.8mm) than in patients with a second cesaren section (33.5 mm).

Double-balloon catheter for induction of labour in women with a previous cesarean section, could it be the best choice?

INTRODUCTION: We analysed the efficacy and safety of double-balloon catheter for cervical ripening in women with a previous cesarean section and which were the most important variables associated with an increased risk of repeated cesarean delivery. MATERIALS AND METHODS: We designed an observational retrospective study of 418 women with unfavourable cervices (Bishop Score <5), a prior cesarean delivery, and induction of labour with a double-balloon catheter. Baseline maternal data and perinatal outcomes were recorded for a descriptive, bivariate, and multivariate analysis. A p value <0.05 was considered statistically significant. RESULTS: Most women improved their initial Bishop Score (89.5%) although only a 20.8% of them went into spontaneous active labour. Finally, 51.4% of the women achieved a vaginal delivery. Five cases of intrapartum uterine rupture (1.2%) occurred. After multivariate analysis, main risk factors for repeated cesarean section were dystocia in the previous pregnancy (OR 1.744; CI 95% 1.066-2.846), the absence of previous vaginal delivery (OR 2.590; CI 95% 1.066-6.290), suspected fetal macrosomia (OR 2.410; CI 95% 0.959-6.054), and duration of oxytocin induction period (OR 1.005; CI 95% 1.004-1.006). The area under the curve was 0.789 (p < 0.001). CONCLUSIONS: Double-balloon catheter seems to be safe and effective for cervical ripening in women with a previous cesarean delivery and unfavourable cervix. In our study, most women could have a vaginal delivery in spite of their risk factors for cesarean delivery. A multivariate model based on some clinical variables has moderate predictive value for intrapartum cesarean section.

Atypical decelerations: do they matter?

OBJECTIVE: To estimate the association between atypical variable decelerations and neonatal acidemia. METHOD: We conducted a one-year case-control study comparing the last thirty minutes before delivery of fetal heart rate tracings of 102 acidemic neonates (umbilical arterial cord gas pH ≤ 7.10) with 100 non-acidemic controls (umbilical arterial cord gas pH > 7.10). Incidence of atypical features and total number of decelerations, number of atypical decelerations, number of slow return decelerations and number of decelerations with loss of moderate variability during deceleration were extracted. We estimated the association between atypical features, neonatal acidemia and neonatal morbidity. RESULTS: Acidemic neonates showed a larger number of atypical decelerations (4 [0-12] vs. 3 [0-10]), "slow return" decelerations (4 [0-11] vs. 1 [0-10]) and decelerations with non-moderate variability (0[0-12] vs. 0 [0-6]) compared to non-acidemic controls. "Slow return" was significantly associated with an increased risk of acidemia at birth (OR 4.46; CI 95%: 2.18 - 9.15) "Slow return" was the most discriminating feature between groups with an AUC: 0.745. CONCLUSION: Certain atypical features, as "slow return" and loss of moderate variability within decelerations are associated with neonatal acidemia. "Slow return" could help in the gradation of acidemia risk levels, as an indicator of gravity.

Diagnostic accuracy of fetal scalp lactate for intrapartum acidosis compared with scalp pH.

OBJECTIVE: To determine the diagnostic accuracy of fetal scalp lactate sampling (FSLS) and to establish an optimal cut-off value for intrapartum acidosis compared with fetal scalp pH. METHODS: A 20-month retrospective cohort study was conducted of all neonates delivered in our institution for whom fetal scalp blood sampling (FSBS) was performed, matching their intrapartum gasometry to their cord gasometry at delivery (n=243). The time taken from the performance of scalp blood sampling to arterial umbilical cord gas acquisition was 45 min at most. Five arterial cord gasometry patterns were set for assessing the predictive ability of both techniques. Subsequent obstetric management for a pathological value was analysed considering the use of both techniques. RESULTS: The optimal cut-off value for FSLS was 4.8 mmol/L: this value has 100% sensitivity and 63% specificity for umbilical arterial cord gas pH≤7.0 and base deficit (BD)≥12 detection, and 100% sensitivity and 64% specificity for umbilical arterial cord gas pH≤7.10 and BD≥12 detection, with a false negative rate of <1.3%, improving fetal scalp pH performance. FSLS showed the best area under the curve (AUC) of 0.86 and 0.84 for both arterial cord gasometry patterns, respectively. Expedite birth following lactate criteria would have been the same as following pH criteria (92 obstetric interventions) with no cases of missed metabolic acidosis. In the cohort, 19.8% of cases were discordant, but no cases of metabolic acidosis were in this group. CONCLUSIONS: FSLS improves the detection of metabolic acidosis via fetal scalp pH with an optimal cut-off value of 4.8 mmol/L. FSLS can be used without increasing obstetrical interventions or missing metabolic acidosis.

Diagnostic Accuracy of the FIGO and the 5-Tier Fetal Heart Rate Classification Systems in the Detection of Neonatal Acidemia.

Objective The objective of this study was to determine ability to detect neonatal acidemia and interobserver agreement with the FIGO 3-tier and 5-tier fetal heart rate (FHR) classification systems. Design This was a case-control study. Setting This study was set at the University Medical Center. Population A total of 202 FHR tracings of 102 women who delivered an acidemic fetus (umbilical arterial cord gas pH ≤ 7.10 and BE < - 8) and 100 who delivered a nonacidemic fetus (umbilical arterial cord gas pH > 7.10) were assessed. A subanalysis was performed for those fetuses who suffered severe metabolic acidemia (pH ≤ 7.0 and BE < - 12). Methods Two reviewers blind to clinical and outcome data classified tracings according to the new 3-tier system proposed by the FIGO and the 5-tier system proposed by Parer and Ikeda. Main Outcome Measures Sensitivity and specificity for detecting neonatal acidemia and interobserver agreement in classifying FHR tracings into categories of both systems were studied. Results The 3-tier system showed a greater sensitivity and lower specificity to detect neonatal acidemia (43.6% sensitivity, 82.5% specificity) and severe metabolic acidemia (71.4% sensitivity, 74.0% specificity) compared with the 5-tier system (36.3% sensitivity, 88% specificity and 61.9% sensitivity, 80.1% specificity, respectively). Both systems were compared by area under the receiver-operating characteristic curve, with comparable predictive ability for detecting neonatal acidemia (FIGO-area under the curve [AUC]: 0.63 [95% confidence interval [CI]: 0.57-0.68] and Parer-AUC: 0.62 [95% CI: 0.56-0.67]). Interobserver agreement was moderate for both systems, but performance at each specific category showed a better agreement for the 5-tier system identifying a pathological tracing (orange or red, κ: 0.625 vs. pathological category, κ: 0.538). Conclusion Both systems presented a comparable ability to predict neonatal acidemia, although the 5-tier system showed a better interobserver agreement identifying pathological tracings.

pH, base deficit or lactate. Which is better for predicting neonatal morbidity?

OBJECTIVE: To determine which parameter of the umbilical arterial cord gas analysis, pH, base deficit (BD) or lactate has a bigger predictive ability for neonatal morbidity at term. METHOD: We conducted a four-year retrospective cohort study including all non-anomalous, singleton, vertex, term births with neonatal acidemia (umbilical arterial cord gas pH ≤ 7.1). The primary outcomes were a composite neurological morbidity and a composite systemic morbidity. The predictive ability of lactate, BD and pH was compared using receiver operator characteristic (ROC) curves. Optimal cutoff values of lactate, BD and pH were estimated based on their maximal Youden Index. RESULTS: We identified 466 acidemic neonates who had paired and validated cord blood gas data. The ROC curve analysis revealed that pH, BD and lactate had a similar predictive ability for neurological (AUC: 0.81; 0.78; 0.83, respectively) and systemic neonatal morbidity (AUC: 0.77; 0.82; 0.82, respectively). The combination of pH ≤ 7.0 and lactate ≥ 7.0 mmol/L presented similar validity to that of pH ≤ 7.0 and BD ≥ 12 mmol/L, but both were comparable to pH alone. CONCLUSIONS: pH, BD and lactate have similar predictive ability for adverse neonatal outcomes among acidemic neonates. Umbilical arterial lactate could replace BD as a measure of the metabolic component in acidemic neonates. However, neither BD nor lactate demonstrated in this study to improve the predictive ability of pH alone for short-term neonatal outcomes.

Deceleration area and fetal acidemia.

AIMS: To compare the predictive ability for neonatal acidemia of individual components of intrapartum cardiotocography (CTG) described by National Institute of Child Health and Human Development (NICHD) system and deceleration area. DESIGN: Case-control study. SETTING: Spanish tertiary obstetrical hospital. POPULATION: CTG patterns of 102 acidemic fetus (umbilical arterial cord gas pH ≤7.10, base deficit (BD) > 8) and 102 nonacidemic controls (umbilical arterial cord gas pH > 7.10). METHODS: Two reviewers blind to clinical and outcome data analyzed the last thirty minutes before delivery of 204 fetal heart rate (FHR) tracings, extracting those features defined by NICHD and certain measures of FHR decelerations, including deceleration area, not considered by this system. OUTCOME MEASURES: The primary outcome was the predictive ability of NICHD features and non-NICHD deceleration measures for fetal acidemia. The secondary outcome was the impact of deceleration area in the last 30 min of labor on gasometry components (pH, BD and lactate). RESULTS: Minimal variability (area under the curve (AUC) 0.74), total number of late (AUC: 0.75) and prolonged decelerations (0.77) were the three NICHD features with the greatest predictive ability for fetal acidemia in the last thirty minutes of labor. Total deceleration area demonstrated the highest discrimination power (AUC: 0.83) of all the analyzed elements. For each cm2 the area increases in the last 30 min of labor, pH decreases 0.08 units, BD increases 0.272 mEq/L and lactate 0.183 mEq/L. CONCLUSIONS: Total deceleration area showed the greatest predictive ability for fetal acidemia and its measure could help to estimate intrapartum fetal acid-base status.

[Massive gestational vulvar edema. A case report and review of literature]. / Edema vulvar masivo gestacional. Reporte de un caso y revisión de la bibliografía.

We report the case of a 22-year-old primiparous, admitted to our hospital with a 2-week history of vulvar edema that had evolved within 24 hours to the point of stopping urine flow and hindering ambulation. The only remarkable finding in relation with the edema was hypoalbuminemia for no apparent cause. The correction of hypoalbuminemia and the establishment of diuretic treatment, with the drainage of the edema allowed for a complete resolution of the edema.