The Significance of ‘Non-Significant’ Meconium Stained Amniotic Fluid (MSAF): Colour versus Contents

The presence of ‘thin’ or ‘non-significant’ meconium stained amniotic fluid (MSAF) is currently being considered by some intrapartum guidelines as ‘low risk’, requiring only an intermittent auscultation and not continuous electronic fetal heart rate monitoring using the cardiotocograph (CTG). Clinicians not only must exclude ‘non-physiological’ causes of MSAF but consider the potential effect of MSAF on fetal wellbeing, irrespective of whether the passage was secondary to a normal physiological process or due to an underlying pathology. Management decisions should be made based on the parity, rate of progress of labour, cervical dilatation at diagnosis, and observed CTG changes and the risk factors such as multiple pregnancy and intra-uterine growth restriction. Presence of any meconium within the amniotic fluid should be considered as an important intrapartum risk factor. The thin meconium may be ‘non-significant’ on visual inspection, but it is very significantfrom the point of view of a fetus, who is covered with toxic materials within the surrounding amniotic fluid

Diagnóstico de madurez pulmonar fetal por velocimetria doppler / Diagnosis of fetal pulmonary maturity by doppler flow assessment

Objetivo: Establecer la relación entre la edad gestacional y la velocidad máxima del ductus arterioso (VmxDA), y determinar si es posible predecir la madurez pulmonar fetal con flujometría Doppler de la VmxDA. Diseño del estudio: Se realizó un estudio de cohortes, prospectivo, con muestreo no probabilístico donde se tomó como población a pacientes sanos que cumplan los criterios de inclusión. Se valoró la velocidad máxima del ductus arterioso. Se estimaron los valores paramétricos y se evaluó el coeficiente regresión y correlación, sensibilidad y especificidad, con la edad gestacional. Se utilizó un intervalo de confianza del 95%, se obtuvo las diferentes velocidades máximas del ductus arterioso según edad gestacional, y su respectivo error estándar junto con sus desviaciones estándar y se correlacionaron con la edad gestacional, para determinar la posibilidad de predecir la madurez pulmonar por flujometría Doppler. Resultados: Se evaluó un total de 824 pacientes donde se evidenció un aumento de la velocidad máxima del ductus arterioso a medida que avanza la edad gestacional. Se encontró dos puntos de inflexión en la curva de la VmxDA a las 28 semanas y a las 35 semanas. Se obtuvo un coeficiente de correlación de 0.97 con un nivel de probabilidad menor de 0.0001. Los valores de sensibilidad y especificidad para predecir madurez pulmonar fueron de 83.9% y 100% para 95 cm/s y 91.5% y 100% para 98 cm/s, con un VPP del 0.709 y un VPN del 1.0. La variabilidad interobservador fue menor de 5%para la VmxDA. Conclusiones: Existe una relación directa entre la edad gestacional y la velocidad máxima del ductus arterioso, pudiendo ser utilizado como un buen predictor de madurez pulmonar fetal.

Objective: To establish the relationship between the gestational age and the maximum velocity of the ductus arteriosus (VmxDA), and to determine if it is possible to predict the fetal lung maturity with Doppler flow assessment of the VmxDA. Study design: A prospective, cohort study was conducted with non-probabilistic sampling where healthy patients who met the inclusion criteria were taken as a population. The maximum velocity of the ductus arteriosus was evaluated. Parametric values were estimated and the coefficient of regression and correlation, sensitivity and specificity was evaluated with gestational age. A 95% confidence interval was used, the different maximum ductus arteriosus velocities were obtained according to gestational age, and their respective standard error along with their standard deviations and they were correlated with gestational age, to determine the possibility of predicting lung maturity by flow assessment of the VmxDA. Results: 824 patients were evaluated where it was evidenced an increase in the maximum velocity of the ductus arteriosus was observed as gestational age progressed. Two inflection points were found in the VmxDA curve at 28 weeks and at 35 weeks. A correlation coefficient of 0.97 was obtained with a probability level of less than 0.0001. The values of sensitivity and specificity to predict lung maturity were 83.9% and 100% for 95 cm / s and 91.5% and 100% for 98 cm / s, with a PPV of 0.709 and a NPV of 1.0. The interobserver variability was less than 5% for the VmxDA. Conclusions: There is a direct relationship between gestational age and the maximum velocity of the ductus arteriosus, which can be used as a good predictor of fetal lung maturity

Controversias actuales para definir las alteraciones del bienestar fetal / Current controversies to define changes in the fetal wellbeing

Como propuesta de diferentes sociedades científicas se estableció el término estado fetal no tranquilizador en sustitución de sufrimiento fetal, que era considerado inespecífico. Esta revisión bibliográfica se efectuó a fin de exponer a la comunidad médica los diferentes términos con que se definen las alteraciones del bienestar fetal y la influencia que el empleo de las expresiones estado fetal no tranquilizador y riesgo de pérdida del bienestar fetal generan en la práctica de Obstetricia. Asimismo, se puso énfasis en la necesidad de buscar un lenguaje técnico más unificado y se concluyó que la formación de estos términos no determina la correspondencia existente entre la evaluación prenatal del feto y su estado al nacer.

As a proposal of different scientific societies the term non reassuring fetal status was coined, substituting it by fetal distress which was considered nonspecific. This literature review was carried out in order to show to the medical community the different terms with which the changes of the fetal wellbeing are defined and the influence that the use of the expressions non reassuring fetal status and the risk of loss of the fetal well-being generate in Obstetrics. Likewise, the necessity of looking for a more unified technical language was emphasized and it was concluded that these terms do not determine the existent correspondence between the prenatal evaluation of the fetus and its status at birth.