Linea nigra
From Wikipedia, the free encyclopedia
Linea nigra (Latin for "black line") is a dark vertical line that appears on the abdomen during pregnancy. The brownish streak is usually about a centimeter in width. The line runs vertically along the midline of the abdomen from the pubis to the xiphoid process — the bottom-most part of the rib cage in the center or tip of the sternum.
It is a type of hyperpigmentation resulting from increased production of the pigment melanin thought to be caused by increased estrogen, the same process that causes the areolas to darken.[1] Why this process of hyperpigmentation occurs on the midline of the abdomen is uncertain. Fair-skinned women show this symptom less often than women with darker pigmentation[citation needed]. Before it appears it may be more faintly visible as a linea alba ("white line").
Linea nigra tends to appear around the second trimester. Some research suggests there may be a link between linea nigra and insulin.[citation needed] Supplementing the diet with folic acid is said to reduce the discoloration.[citation needed] After birth, the line fades slowly, but may never disappear entirely, and sun exposure may cause it to recur.[1]
