Linea nigra

Linea nigra (Latin for "black line"), colloquially known as the pregnancy line, manifests as a linear area of heightened pigmentation frequently observed on the abdominal region during pregnancy.

[2] For pregnant women, the emergence of linea nigra is attributed to an increased production of melanocyte-stimulating hormone by the placenta.

[4] It is typical for the linea nigra to fade and dissipate within several months following childbirth.

Beyond the gestational context, its prevalence is found to be uniformly elevated in either sex during the ages of 11 to 15.

It could also rarely serve as an indicator of underlying hormonal imbalances, genetic disorders, malignancy, inflammation, or even fungal infections.