Linea nigra

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Linea nigra
Other names: Pregnancy line
Linea nigra as seen in a pregnant woman
SpecialtyObstetrics, dermatology
Symptoms1 cm (0.4 in) wide, brownish to blackish line, from the pubis to the belly button[1]
Usual onset3rd month or earlier[2]
Diagnostic methodBased on appearance[1]
Differential diagnosisCafé au lait macules, postinflammatory hyperpigmentation, flagellate hyperpigmentation[1]
TreatmentNo specific treatment[1]
PrognosisGenerally resolves in the year following birth[5]
Frequency>90% of pregnant women[1]

Linea nigra, also known as the pregnancy line, is a line of increased pigmentation seen on the abdomen during pregnancy.[1] It is typically one centimeter (0.4 in) wide, brownish to blackish, and extends vertically in the midline from the pubis to the belly button.[1] Variably, it may extend to the upper abdomen.[1] In first pregnancies, onset is generally in the 3 month; however, it may appear earlier in subsequent pregnancies.[2] It is associated with darkened patches on the cheek and darkened nipples.[6]

The underlying mechanism is unclear but is believed to involved increased estrogen resulting in increased formation of melanin.[1][3] Diagnosis is based on appearance.[1] No specific treatment is required and it generally fades in the year of childbirth.[1][5] The degree of pigmentation can be lessened by either avoiding sun or using sunscreen on the area.[4][1]

Most pregnant women (>90%) are affected to some degree.[1] Those with darker skin are generally more affected.[1] Up to 30% of people on birth control pills may develop the condition, as may children and males.[1][4] The term is from the Latin for "black line".[6]

Signs and symptoms


Although predominantly associated with pregnancy, it can occur in both males and females of all ages. Beyond the gestational context, its prevalence is found to be uniformly elevated in both sexes during the ages of 11 to 15. This is potentially attributable to hormonal fluctuations characteristic of puberty. Subsequent to the age of 15, rates in both males and females declines. Particularly in postpubescent females, it often serves as an indicator of elevated benign estrogens. Rates in both genders drops below 10% following the age of 30. Furthermore, its appearance may ensue subsequent to rapid weight gain over a short interval. It could also rarely serve as an indicator of underlying hormonal imbalances, genetic disorders, malignancy, inflammation, or even fungal infections.[7]

See also


  1. 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 1.14 "Linea nigra". DermNet. Archived from the original on 14 January 2024. Retrieved 11 January 2024.
  2. 2.0 2.1 Perry, Shannon E.; Hockenberry, Marilyn J.; Lowdermilk, Deitra Leonard; Wilson, David; Alden, Kathryn Rhodes; Cashion, Kitty (9 September 2017). Maternal Child Nursing Care - E-Book. Elsevier Health Sciences. p. 162. ISBN 978-0-323-47921-9. Archived from the original on 14 January 2024. Retrieved 11 January 2024.
  3. 3.0 3.1 Tyler, Kelly H. (24 July 2020). Cutaneous Disorders of Pregnancy. Springer Nature. p. 3. ISBN 978-3-030-49285-4. Archived from the original on 15 January 2024. Retrieved 11 January 2024.
  4. 4.0 4.1 4.2 Blackburn, Susan Tucker (2007). Maternal, Fetal, & Neonatal Physiology: A Clinical Perspective. Elsevier Health Sciences. p. 517. ISBN 978-1-4160-2944-1. Archived from the original on 15 January 2024. Retrieved 11 January 2024.
  5. 5.0 5.1 Bobonich, Margaret; Nolen, Mary; Honaker, Jeremy; DiRuggiero, Douglas (14 May 2021). Dermatology for Advanced Practice Clinicians: A Practical Approach to Diagnosis and Management. Lippincott Williams & Wilkins. p. PT1412. ISBN 978-1-9751-4837-9. Archived from the original on 14 January 2024. Retrieved 11 January 2024.
  6. 6.0 6.1 The Science of Pregnancy: The Complete Illustrated Guide From Conception to Birth. Penguin. 29 October 2019. p. 138. ISBN 978-1-4654-9921-9. Archived from the original on 15 January 2024. Retrieved 11 January 2024.
  7. Olufemi, George, Adekunle Olufemi Shittu, Olayiwola Babatunde Enwerem, Eokezie Wachtel, Mitchell Kuti. The incidence of lower mid-trunk hyperpigmentation (linea nigra) is affected by sex hormone levels. National Medical Association. OCLC 678245464. Archived from the original on 2023-11-22. Retrieved 2023-12-14.

External links