The dark vertical line that can develop around the second trimester of pregnancy is known as the ‘linea nigra’, which literally refers to the black line. About 75% of pregnant women develop a linea nigra, stretching anywhere from the pelvic bone to the belly button and from the belly button to up between the ribs.
In some 17th century medical textbooks, doctors suggest that the linea nigra means that a woman is carrying twins and that her uterus is separating into two. A more recent old wives’ tale claims that if the linea nigra runs only up to your belly button, it’s a girl. And if it runs beyond your belly button towards your ribs, you’re having a boy.
Unfortunately, the reality of the linea nigra is not quite so exciting. The line has actually always been there but before pregnancy is known as your ‘linea alba’, which means the white or colourless line. The line darkens in pregnancy because of changes in hormones (joy) that lead to extra Melanin production. That’s also why your face and nipples might get a bit darker through pregnancy too.
The linea nigra is a completely normal part of pregnancy and can’t be prevented. It will fade after pregnancy in its own time - this process can be different for every woman.
Rather than waiting and hoping for it to go, we like to think about it as a line in time, marking the moment when you shifted from woman to mother. Just as we divide the world into east and west hemispheres, your linea nigra marks the moment when you jumped from before to after and your whole world changed.