what is "pre-ductus"and "post-ductus"?

Hi. I am a student, studying medical issues.
When I read a book, I found  words "pre-ductus" and "post-ductus".
I could not understand what they are and I thought these words are related to
functions of the heart.

By the way, I am not a English-speaker. If you know what they are, let me know.

Best wishes.

[ireneo]

I'm not a medical student but I found that pre and post ductus refers to the ductus ateriosus in fetuses. According to Wikipedia:

In the developing fetus, the ductus arteriosus (DA), also called the ductus Botalli or ductus Layton in the United Kingdom, is a shunt connecting the pulmonary artery to the aortic arch. It allows most of the blood from the right ventricle to bypass the fetus' fluid-filled lungs, protecting the lungs from being overworked and allowing the left ventricle to strengthen. There are two other fetal shunts, the ductus venosus and the foramen ovale.

In other articles they checked the oxygen levels in developing fetuses in relation to the amount of oxygen the mother is getting. I would guess it has something to do with checking the O2 levels before (pre) the DA and after (post) the DA area in relation to the blood flow.

Can you find info on DA in your own language so that you might understand it more easily? Perhaps a library nearby?