In preeclampsia, these uteroplacental arteries become fibrous causing them to narrow, which means less blood gets to the placenta.

但在子痫前期中，子脉纤维化导致脉狭窄，意味着输送至的血液就减少了。

Normally, during pregnancy, the spiral arteries dilate to 5-10 times their normal size and develop into large uteroplacental arteries capable of delivering large quantities of blood to the developing fetus.

正常妊娠中，子脉可以扩张至原先直径的5-10倍，并发育成粗大的子脉，从而向发育中的儿输送大量血液。