The Linea Nigra or Linea Negra (Latin for ‘dark line’) is a dark vertical line that appears on the abdomen of many pregnant women.
Usually the Linea Negra appears during the second trimester; in or about the fifth month of pregnancy, and is more common among dark skinned women than lighter skinned women.
This dark line that appears in pregnancy is perfectly normal and is thought to be caused by hormonal changes in the body that increase melanin production.
A majority of women experience this, and though for most it disappears after pregnancy, for many women it never fades completely.
It may also be accompanied by other changes such as brown splotchy patches on the face (cloasma or the mask of pregnancy), freckles, darkened nipples, moles, and other signs of hyperpigmentation.
One should take care to have enough folic acid during pregnancy; its deficiency is known to be associated with hyperpigmentation. Also limit sun exposure since that can also cause such discoloration of the skin.
Tradition has it, that if one has their Linea Negra extend from the pubic bone right up to the rib cage, then you’re having a boy; and if the line ends at the belly button then it’s a girl you’re carrying. It is seen to be true about half of the time!