What is noticeable about the fallopian tubes during pregnancy?

During pregnancy, the fallopian tubes experience changes that are important for reproductive function. They are not completely inactive; instead, their role shifts to facilitate the transport of the fertilized egg (zygote) towards the uterus for implantation. While there may be changes in their motility, particularly the contractions they perform to help move the zygote along, saying they are completely inactive doesn't reflect their dynamic role.

The fallopian tubes do enlarge during the early stages of pregnancy due to increased blood flow and hormonal changes, making this option a more accurate description of what occurs. Thus, the option indicating that they are completely inactive does not capture the reality of their physiological activity during pregnancy. They do not remain constant in size or exhibit rapid motion like other structures in the reproductive system; rather, they play an essential part in the process following fertilization.