Natsuyama E, Nishimura T
Nihon Sanka Fujinka Gakkai Zasshi. 1980 Nov;32(11):1829-38.
A newly developed manipulation of ultrasonic tomography has been successfully applied for determining the fetal sexes, based on the findings obtained by preliminary studies on the neonatal pelvic and external genitalia. The results are as follows: 1) In neonates, distinct sex differences in length and shape of the anoperineogenital (APG) area were observed by two-dimensional ultrasonic tomography. Transverse tomography of superficial portion of APG gave different images of M for males and of F for females. Frontal tomography produced images of the scrotum and the major labia. 2) In fetuses, distinction in the M and F images of APG between the both sexes was constantly recognized on the 20th week or later. The images representing the triangle formed by the bilateral tuber-ossis ischii and the ventral end of the external genitalia was found quite useful in determining the sexes between the 15th and 20th week of gestation. 3) Determination of fetal sexes in 604 pregnancies (including 4 pairs of twins) between 23th and 39th week of gestation turned out correct in 99.8% of the cases as compared with the sexes after their deliveries. 4) Although feasibility of this method exceeded 50% of the cases of 18th week of gestation, the optimal term for the determination of fetal sexes was estimated between 23 and 32 weeks of gestation.
基于对新生儿骨盆和外生殖器的初步研究结果，一种新开发的超声断层扫描操作已成功应用于确定胎儿性别。结果如下：1）在新生儿中，通过二维超声断层扫描观察到肛门会阴生殖区（APG）的长度和形状存在明显的性别差异。APG浅表部分的横向断层扫描给出了男性为M型、女性为F型的不同图像。 frontal断层扫描产生了阴囊和大阴唇的图像。2）在胎儿中，在第20周及以后，两性之间APG的M型和F型图像差异始终可以识别。发现由双侧坐骨结节和外生殖器腹端形成的三角形图像在妊娠第15至20周之间确定性别非常有用。3）在妊娠第23至39周的604例妊娠（包括4对双胞胎）中，与分娩后的性别相比，胎儿性别的确定在99.8%的病例中是正确的。4）尽管该方法在妊娠第18周的病例中的可行性超过了50%，但确定胎儿性别的最佳孕周估计在妊娠第23至32周之间。
