Reitter Anke, Daviss Betty-Anne, Bisits Andrew, Schollenberger Astrid, Vogl Thomas, Herrmann Eva, Louwen Frank, Zangos Stephan
Department of Obstetrics and Gynecology, Goethe University, Frankfurt, Germany.
Midwifery Division, Department of Obstetrics and Gynecology, Montfort Hospital, Ottawa, ON, Canada.
Am J Obstet Gynecol. 2014 Dec;211(6):662.e1-9. doi: 10.1016/j.ajog.2014.06.029. Epub 2014 Jun 17.
The purpose of this study was to assess the impact of different positions on pelvic diameters by comparing pregnant and nonpregnant women who assumed a dorsal supine and kneeling squat position.
In this cohort study from a tertiary referral center in Germany, we enrolled 50 pregnant women and 50 nonpregnant women. Pelvic measurements were obtained with obstetric magnetic resonance imaging pelvimetry with the use of a 1.5-T scanner. We compared measurements of the depth (anteroposterior (AP) and width (transverse diameters) of the pelvis between the 2 positions.
The most striking finding was a significant 0.9-1.9 cm increase (7-15%) in the average transverse diameters in the kneeling squat position in both pregnant and nonpregnant groups. The average bispinous diameter in the pregnant group increased from 12.6 cm ± 0.65 cm in the supine dorsal to 14.5 cm ± 0.64 cm (P < .0001) in the kneeling squat; in the nonpregnant group the increase was from 12 cm ± 0.76 cm to 13.9 cm ± 1.04 cm (P < .0001). The average bituberous diameter in the pregnant group increased from 13.6 cm ± 0.93 cm in the supine dorsal to 14.5 cm ± 0.83 cm (P < .0001) in the kneeling squat position; in the nonpregnant women the increase was from 12.6 cm ± 0.92 cm to 13.5 cm ± 0.88 cm (P < .0001).
A kneeling squat position significantly increases the bony transverse and anteroposterior dimension in the mid pelvic plane and the pelvic outlet. Because this indicates that pelvic diameters change when women change positions, the potential for facilitation of delivery of the fetal head suggests further research that will compare maternal delivery positions is warranted.
本研究旨在通过比较采取仰卧位和跪蹲位的孕妇与非孕妇，评估不同体位对骨盆直径的影响。
在德国一家三级转诊中心开展的这项队列研究中，我们纳入了50名孕妇和50名非孕妇。使用1.5-T扫描仪，通过产科磁共振成像骨盆测量法获取骨盆测量值。我们比较了两个体位之间骨盆深度（前后径）和宽度（横径）的测量值。
最显著的发现是，孕妇组和非孕妇组在跪蹲位时平均横径均显著增加0.9 - 1.9厘米（7% - 15%）。孕妇组双棘径从仰卧位时的12.6厘米±0.65厘米增加至跪蹲位时的14.5厘米±0.64厘米（P < .0001）；非孕妇组则从12厘米±0.76厘米增加至13.9厘米±1.04厘米（P < .0001）。孕妇组坐骨结节间径从仰卧位时的13.6厘米±0.93厘米增加至跪蹲位时的14.5厘米±0.83厘米（P < .0001）；非孕妇从12.6厘米±0.92厘米增加至13.5厘米±0.88厘米（P < .0001）。
跪蹲位可显著增加中骨盆平面和骨盆出口的骨性横径及前后径。由于这表明女性改变体位时骨盆直径会发生变化，因此在促进胎头娩出方面的潜在作用提示有必要开展进一步研究以比较产妇分娩体位。
