Fong Bianca F, Buis Albertine J E, Savelsbergh Geert J P, de Vries Johanna I P
Institute for Fundamental and Clinical Human Movement Sciences, van der Boechorststraat 9, 1081 BT Amsterdam, The Netherlands.
Early Hum Dev. 2005 Jun;81(6):519-27. doi: 10.1016/j.earlhumdev.2004.11.003. Epub 2005 Jan 16.
In previous research, an age-related developmental trend towards increasing arm flexion has been found for cephalic fetuses.
To determine if the development of arm posture in breech fetuses is comparable to that of cephalic ones.
Fetal arm posture was studied longitudinally by means of real-time ultrasound in 13 healthy breech and 10 healthy cephalic fetuses. Observations started from 33 weeks gestational age until birth and were performed weekly in the breech group and every 2 weeks in the cephalic group.
No difference could be found in arm posture between the left and the right arm in either group. Both breech and cephalic fetuses showed a clear preference for flexion in elbow and finger joints at all studied ages. After 36 weeks gestational age, the breech group showed significantly less wrist flexion when compared to the cephalic group (p = 0.037). A clear preference for location of the fetal hands near the fetal head could be observed for both groups.
As there is no evidence for an abnormal neuromotor development in healthy breech fetuses, the observed difference in wrist flexion is probably due to differences in intrauterine environment. Because of the preference for location of the hands in the vicinity of the fetal head, breech fetuses probably experience a less restricted environment (in the upper part of the uterus) than cephalic fetuses (in the lower part of the uterus).
在先前的研究中，已发现头位胎儿存在与年龄相关的手臂屈曲增加的发育趋势。
确定臀位胎儿手臂姿势的发育是否与头位胎儿相当。
通过实时超声对13例健康臀位胎儿和10例健康头位胎儿的手臂姿势进行纵向研究。观察从孕33周开始直至出生，臀位组每周进行观察，头位组每2周进行观察。
两组中左右臂的手臂姿势均未发现差异。臀位和头位胎儿在所有研究年龄段的肘关节和手指关节均明显偏好屈曲。孕36周后，与头位组相比，臀位组的腕关节屈曲明显减少（p = 0.037）。两组均观察到胎儿手部明显偏好位于胎儿头部附近。
由于没有证据表明健康臀位胎儿存在异常神经运动发育，观察到的腕关节屈曲差异可能是由于子宫内环境的差异。由于手部偏好位于胎儿头部附近，臀位胎儿可能比头位胎儿（子宫下部）在子宫上部经历的限制环境更少。
