Revisión bibliográfica: ecografía intraparto / Review: intrapartum ultrasound

The evaluation of labor is the clinical process by which variables are analyzed in order to determine whether the patient is in labor, which by definition includes regular uterine contractions that increase in frequency and intensity, associated with dilation cervical. This is done through the anamnesis and physical examination, specifically through the evaluation of contractions and vaginal examination, the latter is intended to specify the degree of dilation, cervical effacement that the patient presents and also allows to a certain degree, establish the presentation, attitude and variety of position in which the fetus is located. From this premise, it is proposed that vaginal examination, since it is operator dependent, is not an objective evaluation, therefore, there is a need to reach consensus on the evaluation, and in order to carry it out, evaluation with ultrasound is proposed, which has as a purpose to objectify the variety of position and presentation of the fetus. Due to the above, this article aims to capture the knowledge that is currently possessed about the uses and methodology that intrapartum ultrasound presents.

Preliminary study of prenatal ultrasound in predicting delivery mode of full-term primipara / 中华超声影像学杂志

Objective:To explore the feasibility of prenatal ultrasound in predicting delivery mode of full-term primipara.Methods:The study prospectively enrolled primiparas with gestational age ≥37 weeks, singleton, cephalic and no contraindications to vaginal delivery who underwent routine prenatal examination in the Third Affiliated Hospital of Sun Yat-sen University from September 2020 to February 2021.In addition to routine fetal ultrasound examination, the transperineal ultrasound examination was performed to assess the angle of progression (AOP), head perineum distance (HPD), the angle of pubic arch and the anteroposterior diameter, left and right diameter, area and perimeter of levator ani hiatus of pregnant women in different states were measured; Cervical length (CL) was examined by transvaginal ultrasound. The delivery mode was tracked, and the indicators related to natural delivery were screened out. Receiver operating characteristic (ROC) curve was used to evaluate the effectiveness of relevant indicators in predicting natural delivery.Results:A total of 142 cases were included in this study, including 112 cases of natural delivery and 30 cases of manual intervention delivery. There were no significant differences in age, gestational weeks, biparietal diameter, head circumference, body mass index (BMI) and neonatal weight between the natural delivery group and the manual intervention delivery group (all P>0.05). Multivariate regression analysis showed that AOP was associated with natural delivery( OR=1.048, P=0.008). ROC curve analysis showed that the area under the curve was 0.648 with AOP 96.92° as the node, and the specificity and positive predictive values were 83.33% and 0.909 1 respectively. Conclusions:It is feasible to predict the mode of delivery by prenatal ultrasound in full-term primiparas. AOP is related to the mode of delivery, which can provide more reference information for clinical practice.

Mueller-Hillis maneuver and angle of progression: Are they correlated? / Manobra de Mueller-Hillis e ângulo de progressão: eles estão correlacionados?

Summary Objective: Mueller-Hillis maneuver (MHM) and angle of progression (AOP) measured by transperineal ultrasound have been used to assess fetal head descent during the second stage of labor. We aimed to assess whether AOP correlates with MHM in the second stage of labor. Method: A prospective observational study including women with singleton pregnancy in the second stage of labor was performed. The AOP was measured immediately after the Mueller-Hillis maneuver. A receiver-operating characteristics (ROC) curve analysis was performed to determine the best discriminatory AOP cut-off for the identification of a positive MHM. A p-value less than 0.05 was considered statistically significant. Results: One hundred and sixty-six (166) women were enrolled in the study and 81.3% (n=135) had a positive MHM. The median AOP was 143º (106º to 210º). The area under the curve for the prediction of a positive maneuver was 0.619 (p=0.040). Derived from the ROC curve, an AOP of 138.5º had the best diagnostic performance for the identification of a positive MHM (specificity of 65% and a sensitivity of 67%). Conclusion: An AOP of 138º seems to be associated with a positive MHM in the second stage of labor.

Resumo Objetivo: A manobra de Mueller-Hillis (MHM) e o ângulo de progressão da apresentação (AOP) medido através de ecografia transperineal têm sido utilizados para avaliar a descida do polo cefálico durante o segundo estágio do trabalho de parto. O objetivo do nosso trabalho foi avaliar se o AOP se correlaciona com a MHM no segundo estágio do trabalho de parto. Método: Conduzimos um estudo observacional e prospectivo. Incluímos mulheres com gravidez unifetal com feto em apresentação cefálica, no segundo estágio do trabalho de parto. O AOP foi medido imediatamente após a manobra de Mueller-Hillis. Foi construída uma curva ROC (receiver-operating characteristics) para determinar o melhor AOP para a identificação de uma manobra positiva. Um valor p inferior a 0,05 foi considerado estatisticamente significativo. Resultados: Cento e sessenta e seis mulheres (166) foram incluídas no estudo, e em 81,3% (n=135) a MHM foi positiva. A mediana do AOP foi de 143º (106º a 210º). A área abaixo da curva para a previsão de uma manobra positiva foi 0,619 (p=0,040). Derivado da curva ROC, um AOP de 138,5º teve o melhor desempenho diagnóstico para a identificação de uma MHM positiva (especificidade de 65% e sensibilidade de 67%). Conclusão: Um AOP de 138º parece estar associado com uma MHM positiva no segundo estágio de trabalho de parto.

A study on clinical application of intrapartum ultrasound / 中华医学超声杂志（电子版）

Objective To discuss the clinical application of getting the images related to the partogram content using the intrapartum ultrasound. Methods One hundred twenty-three pregnant women who tried vaginal delivery in Huai'an Maternity and Children Hospital were included in this study. Intrapartum ultrasound was performed during the progression of labor every two hours. To obtain the images related to the fetal position by transabdominal or transperineal ultrasound in transverse view, determining the fetal head position; to obtain the images related to the fetal head station by transperineal ultrasound in mid-sagittal and transverse views , measuring the angle of progression (AOP) and the fetal head-perineum distance (HPD); to obtain the images related to the cervical dilatation by transperineal ultrasound in transverse view, measuring the anteroposterior diameter of the cervical dilatation. Results This study included 123 pregnant women, 123 images were obtained related to the fetal position; 122 images of AOP related to the fetal head station were measured; and 123 images of HPD related to the fetal head station were measured; 121 images related to the cervical dilatation, all the images can clearly displayed various ultrasonic markers, which can be used to determine the fetal position, the fetal head station and the cervical dilation. Conclusion Intrapartum ultrasound could get the images related to the partogram content, it could be studied to use in labor.