RESUMO
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).
RESUMO
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.
