Estudio preliminar de la acción del músculo obturador interno sobre el diámetro biespinoso pélvico / Preliminary study of the action of the internal obturator muscle on the pelvic bispinous diameter

Objetivo. Evaluar el efecto de la contracción activa isométrica de los músculos obturadores internos en el diámetro biespinoso de la pelvis menor en mujeres nulíparas. Sujetos y métodos. Estudio cuasiexperimental antes-después: posición de reposo muscular versus estado de contracción activa, de las medias aritméticas de 3 mediciones consecutivas del diámetro biespinoso de la pelvis menor obtenidas mediante RM realizadas sobre 6 mujeres nulíparas. Resultados. No se aprecian diferencias estadísticamente significativas (p=0,08) en el diámetro biespinoso entre el reposo y durante la contracción isométrica de los músculos obturadores internos: en valores absolutos, la media de la diferencia entre ambas mediciones es de -5,4 píxeles (IC del 95%, -11,8 a 0,9). Conclusiones. En jóvenes mujeres nulíparas no es posible aumentar el diámetro biespinoso del estrecho medio de la pelvis menor realizando una contracción isométrica voluntaria de los músculos obturadores internos partiendo de una posición neutra de ambas caderas (AU)

Objective. To evaluate the effect of isometric active contraction of the internal obturator muscles on the bispinous diameter of the minor pelvis in nulliparous women. Subjects and methods. We performed a quasi-experimental study with pre-test-post-test: resting muscle position versus active contraction. We calculated the arithmetic mean of three consecutive measurements of the bispinous diameter of the minor pelvis obtained by magnetic resonance imaging performed in six nulliparous women. Results. No statistically significant differences (P=.08) in the bispinous diameter were found between rest and during isometric contraction of the internal obturator muscles: in absolute values, the mean difference between the two measurements was - 5.4 pixels (95% CI: -11.8 to 0.9). Conclusions. The bispinous diameter of the minor pelvis cannot be increased in young nulliparous women by means of isometric contraction of the internal obturator muscles starting from a neutral position of both hips (AU)

Estudio prospectivo, aleatorizado y controlado para evaluar la utilidad de la radiopelvimetría en la inducción de parto en primigrávidas / Prospective, randomised and controlled study to evaluate the usefulness of radiopelvimetry in induced labour in primigravidae

Introducción: Existen muy pocos estudios publicados en la literatura científica que evalúen la utilidad real de la radiopelvimetría (RPM). Las recomendaciones actuales acerca de su empleo están basadas en un único metaanálisis que incluye tan sólo 4 estudios con muy escaso nivel de evidencia científica. Objetivos: Evaluar la utilidad de la RPM en la inducción del parto en mujeres primíparas para el diagnóstico de la desproporción pélvico-cefálica y analizar su influencia en la duración del parto, la mortalidad neonatal y la tasa de cesáreas. Material y métodos: Se ha realizado un estudio observacional prospectivo, aleatorizado y doble ciego en una población de 264 gestantes primigestas en las que estaba indicada la inducción del parto. Resultados: La RPM no influye en la tasa de cesáreas ni en los resultados perinatales y presenta un valor predictivo bajo como factor pronóstico de la vía del parto (AU)

Introduction: There are very few studies published in the scientific literature to assess the real value of the x-ray pelvimetry (X-PM). The current recommendations on its use are based on a single meta-analysis that includes only four studies with a very low level of scientific evidence. Objectives: To evaluate the usefulness of the X-PM in induction in primiparous women for the diagnosis of pelvic-cephalic disproportion and analysing its influence on the duration of pregnancy, neonatal mortality and the rate of caesarean sections. Materials and methods: The observational, prospective, randomised, double-blind, study, in a population of 264 primigravid pregnant women in whom induction of labour was an indication. Results: X-ray pelvimetry did not influence the rate of caesarean section or the perinatal results, and has a low predictive value as a prognostic factor in the method of delivery (AU)

Trends in the use of pelvimetry techniques.

Assessment of maternal pelvic dimensions is usually considered necessary where vaginal delivery is contemplated in a breech presentation or if reduced pelvic dimensions are suspected in a current or previous pregnancy. Pelvimetry techniques include computed tomography (CT), conventional radiography, digital fluorography and magnetic resonance imaging (MRI). The first three techniques result in a radiation dose to mother and fetus which, depending on how the technique is performed, can vary by up to 40-fold. Of the techniques using X-rays, CT pelvimetry with a lateral scanogram generally gives the lowest radiation dose and conventional radiography using an air gap technique with a single lateral view is a relatively low-dose alternative where CT is not available. A questionnaire was sent to 227 hospitals during 1993 and 1996 to assess whether there was a move towards lower dose techniques of pelvimetry. The results show a trend away from conventional pelvimetry (48.4% in 1993 to 28% in 1996) with a small proportion of centres using MRI (4%) in 1996. Of the centres still using conventional pelvimetry, relatively few were using a low-dose air-gap technique (2.1% in 1993 to 10.9% in 1996). An increasing majority of centres were using one-view CT (69.3% in 1993 and 80.4% in 1996) but a significant proportion were still performing more than one view. This study shows that there was a move towards lower dose techniques of pelvimetry but that there were still many hospitals that had not implemented a policy of reducing radiation exposure in these patients.