Plenty of pregnant people will tell you that the body goes through a lot of changes when carrying a baby—expectant parents can experience a myriad of side effects along the way, from food cravings to stretch marks, to postpartum hair loss later down the line. Another common body change is a dark line developing on the stomach during pregnancy, which in medical terms is called linea nigra.
We asked Lesley Gilchrist, registered midwife and co-founder of My Expert Midwife, to explain what the line seen on the belly during pregnancy is, what causes it, and whether or not anything can be done to prevent linea nigra.
What causes linea nigra?
"Linea nigra [which literally means 'black line' in Latin] is the dark line that can develop down the center of your bump as your pregnancy progresses," says Lesley. "This line usually stretches from the top of the pubic hair to the belly button, although it sometimes extends to the breast too."
She adds that it is caused by the increased estrogen levels experienced in pregnancy, which boost the body's production of melatonin (a natural substance that gives your skin pigment). Typically, it appears around the midway point of pregnancy and is no thicker than half an inch wide (although in some it can be wider). Non-pregnant people may also have linea nigra, likely caused by hormones. Lesley also notes that the linea nigra line can grow darker if a bump is exposed to sunlight. "Some women also experience more hair growth on their bump too," she says.