In your second trimester, you may look down at your growing belly one day to discover a dark line running from your belly button to your pubic area. Before you reach for the cocoa butter in a panic thinking that it's some kind of stretch mark, you should know that this line is perfectly normal, and that it's called the linea nigra. But what exactly is it?
There's no real purpose of the linea nigra – old wives' tales have claimed that it's a way to determine the sex of your baby (if it stops at your navel, it's a boy, but if it goes all the way to your ribs, it's a girl), but there's no actual scientific evidence proving this. You're better off looking at your ultrasound!
Rather, the linea nigra is just the result of your pregnancy hormones going haywire as usual. During a pregnancy, your skin often experiences color changes as your hormones increase the amount of melanin (the pigment responsible for skin coloration) that you have in your body.
That's why you may have noticed your areolas getting a bit darker and some of your moles and freckles looking more pronounced. You might also experience darker skin on your face, usually around the eyes and nose, which is known as "the mask of pregnancy." As for the linea nigra, some women have the line already even before they become pregnant, but it's just too lightly colored to notice.
Unfortunately, there's nothing you can do to prevent or get rid of the linea nigra and other skin discolorations during pregnancy, but you can keep them from intensifying by using sunblock. And don't worry – they'll fade away soon after you deliver!