What is the strange brown line on your pregnant belly and does it go away?

This line never went away on my belly my son is now 6 and I still can't get it to go away. My mom also still has this same line and she is 55 years old. So don't say that it's not permanant because for some it may be. It goes away, it is a pregnant thing only, not permanant (and very common). Someone told me it was a birth line and when it went from my belly button to my vagina it was time to give birth, I don't know if this is true or not but I can tell you it goes away after you give birth. It is called the linea nigra (black line). It is very common, and just caused by your hormones affecting your skin tone. You have probably noticed your nipples are larger and darker too. Some women get like a big freckle across the middle of the face too. It all goes away once the baby is born. The line doesnt always go away straight after the baby is born. I had my baby over 2 months ago and it still hasn't gone away. I have heard that one reason for skin discolourations is a lack of folate and increasing your folate intake makes the line go away.