Institute of Mechanical Engineering, Faculty of Engineering, University of Porto, Oporto, Portugal.
Am J Obstet Gynecol. 2010 Sep;203(3):217.e1-6. doi: 10.1016/j.ajog.2010.03.038. Epub 2010 May 15.
The purpose of this study was to investigate the influence of fetal head flexion during vaginal delivery with a 3-dimensional computational finite element model.
A finite element model of the pelvic skeletal structure, pelvic floor, and fetus was developed. The movements of the fetus during birth were simulated in engagement, descent, flexion, internal rotation, and extension of the fetal head. The opposite forces against the fetal descendent and the stress of the pelvic floor muscles were obtained on simulations with different degrees of head flexion.
The simulated increase in fetal head flexion is associated with lower values of opposite forces against the fetal descent. The descending fetus with abnormal head flexion also meets resistance in later stations. Lower stress on the pelvic floor was demonstrated with simulated increase in fetal head flexion during vaginal delivery.
This analytic evidence suggests that the fetal head flexion during vaginal delivery may facilitate birth and protect the pelvic floor.
本研究旨在通过三维计算有限元模型探讨胎儿头部在阴道分娩过程中的弯曲对分娩的影响。
建立骨盆骨骼结构、骨盆底和胎儿的有限元模型。在胎头衔接、下降、弯曲、内旋转和伸展等分娩过程中模拟胎儿的运动。对不同程度的头部弯曲进行模拟，获得对胎儿下降的相反力和骨盆底肌肉的应力。
模拟胎儿头部弯曲增加与对胎儿下降的相反力值降低相关。在异常头部弯曲的下降胎儿中，在后期胎方位也会遇到阻力。阴道分娩过程中模拟胎儿头部弯曲增加时，骨盆底的压力降低。
该分析结果表明，胎儿头部在阴道分娩过程中的弯曲可能有助于分娩并保护骨盆底。
