What's already known about this topic?

The identification of vasa previa still remains difficult even for well‐trained obstetricians. Distinction of fetal from maternal veins is especially challenging because both have a slow blood velocity.

What does this study add?

Changes in venous flow with maternal respiration in vessels around the uterine cervix or lower uterine segment differentiate maternal from fetal vessel.

中文翻译：

---

在前置血管的情况下如何区分胎儿的丝状静脉与母体血流。

关于这个主题，我们已经知道了什么？

即使对于训练有素的产科医生来说，识别前置血管仍然很困难。区分胎儿和母体静脉尤其具有挑战性，因为两者的血流速度都很慢。

这项研究增加了什么？

子宫颈周围或子宫下段血管中随着母体呼吸的静脉血流变化将母体与胎儿血管区分开来。