Linea nigra (Latin for "black line") is a dark vertical line that appears on the abdomen during about three quarters of all pregnancies. 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 umbilicus, but can also run from the pubis to the top of the abdomen. Linea nigra is due to increased melanocyte-stimulating hormone made by the placenta, which also causes melasma and darkened nipples. Fair-skinned women show this phenomenon less often than women with darker pigmentation. Before it appears, it may be more faintly visible as a white line.
See also 
- Estève E, Saudeau L, Pierre F, Barruet K, Vaillant L, Lorette G (1994). "[Physiological cutaneous signs in normal pregnancy: a study of 60 pregnant women]". Ann Dermatol Venereol (in French) 121 (3): 227–231. PMID 7832550.
- She Knows Network: "What's that line? All about linea nigra"
- Heffner, Linda (2010). The Reproductive System at a Glance. Wiley-Blackwell. p. 51. ISBN 978-1-4051-9452-5.
|This medical sign article is a stub. You can help Wikipedia by expanding it.|