Cyr D R, Mack L A, Schoenecker S A, Patten R M, Shepard T H, Shuman W P, Moss A A
Radiology. 1986 Oct;161(1):119-21. doi: 10.1148/radiology.161.1.2945223.
Ten fetuses underwent ultrasound scanning at 7-10 weeks gestational (postmenstrual) age. In all cases, an echogenic mass measuring 0.5-1.0 cm was demonstrated within the base of the umbilical cord at its insertion into the fetal abdomen. No area with echogenicity characteristic of the small bowel was identified within the lower part of the fetal abdomen. All fetuses were reexamined 4-12 weeks later, at which time the mass in the umbilical cord was no longer seen, and normal fetal bowel was visualized in the lower abdominal cavity of the fetus. This sequence of findings appears to represent the sonographic demonstration of normal fetal bowel migration early in gestation and should not be confused with defects of the abdominal wall such as omphalocele or gastroschisis.
10例胎儿在孕（月经周期后）7至10周时接受了超声扫描。在所有病例中，在脐带插入胎儿腹部处的脐带基部可见一个大小为0.5至1.0厘米的强回声团块。在胎儿腹部下部未发现具有小肠回声特征的区域。所有胎儿在4至12周后再次接受检查，此时脐带中的团块已不再可见，且在胎儿下腹腔中可见正常的胎儿肠管。这一系列表现似乎代表了妊娠早期正常胎儿肠管迁移的超声显示，不应与腹壁缺陷如脐膨出或腹裂相混淆。
