Think of the linea nigra as a line of honor.
Q: I'm five months along and have noticed a strange dark line on my belly? Is it dangerous?
A: Nope. While the linea nigra, or "black line," may be disconcerting, it's perfectly harmless—and perfectly normal. In fact, up to 75 percent of women will experience this hormone-induced darkening of the skin during pregnancy.
According to OB-GYN Michelle Tollefson, M.D., an assistant professor in the department of health professions, integrative therapies program at Metropolitan State College of Denver, the condition often appears in the second trimester and persists throughout pregnancy. Typically about 1 centimeter in width, the line usually starts at the pubic bone and continues up to the belly button, though it can extend to just below the breast in some cases. "Still," she says, "It's considered cosmetic and nothing that is worrisome in pregnancy."
The condition typically resolves on its own within a few months of delivery, so many experts advise not treating it—especially during pregnancy or if you are breastfeeding. "Stay away from bleaching creams, as they often contain hydroquinone, which has not been proven safe to use if you are pregnant or nursing," says Vaneeta Sheth, M.D., an associate physician and instructor in dermatology at Brigham and Women's Hospital in Boston. She adds that these creams may be used after delivery if you're formula-feeding, or you could try a fade cream or topical retinol. If you want a natural approach, try applying a little lemon juice to your skin. "Some women say the acids help fade hyperpigmentation," Sheth says.