Hasson H M
Br J Obstet Gynaecol. 1982 Sep;89(Suppl 4):1-10. doi: 10.1111/j.1471-0528.1982.tb15064.x.
The endometrial cavity is an isosceles trapezoid that changes in shape with the phase of the cycle. The distance from the fundus to where the cavity narrows to 12 mm is the effective length. This and the total length of the uterine cavity can be measured with the Wing Sound. IUCD complications are more frequent if the length of a device exceeds the effective length or the width of the uterine cavity. Devices must be designed to fit the uterine cavity and to conform to physiological changes in the shape of the organ.
子宫内膜腔是一个等腰梯形,其形状随月经周期的阶段而变化。从宫底到宫腔变窄至12毫米处的距离为有效长度。这一长度以及子宫腔的总长度可用Wing Sound测量。如果宫内节育器的长度超过有效长度或子宫腔的宽度,其并发症会更频繁。宫内节育器的设计必须适合子宫腔,并符合该器官形状的生理变化。