A dark, vertical line on your stomach is called a linea nigra. A linea nigra is very common for pregnant people. It’s less common but does develop in men, nonpregnant women, and even children.

A linea nigra isn’t harmful. It’s likely caused by shifts in hormones. The increase in hormones causes melanin-producing cells in the skin to produce more pigment. Because the linea alba is always present (it’s just too light to be seen), the increased pigment makes the line very obvious.

For most people, the line will disappear on its own. There’s no treatment, but if you’re concerned about underlying issues that may be causing the dark line, talk with a doctor. They can help rule out issues that may be contributing to fluctuating hormone levels.


American College of Obstetricians and Gynecologists. Patient FAQs: Skin Conditions in Pregnancy. Last reviewed June 2020. https://www.acog.org/womens-health/faqs/skin-conditions-during-pregnancy [Accessed March 2021]

Tunzi, M and Gray, G. Common Skin Conditions During Pregnancy. American Family Physician. January 2007. https://www.aafp.org/afp/2007/0115/p211.html [Accessed March 2021]

Motosko CC, Bieber AK, Pomeranz MK, et. al. Physiologic changes of pregnancy: A review of the literature. International Journal of Women’s Dermatology. October 2017. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5715231/ [Accessed March 2021]

Vora RV, Gupta R, Mehta MJ, et. al. Pregnancy and skin. Journal of Family Medical Primary Care. October 2014. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4311336/ [Accessed March 2021]