areola

The areola is a small, pigmented area, most commonly referring to the colored ring around the nipple of the breast. During pregnancy, the areola darkens significantly, becoming a deeper bronze or brownish-black, depending on the individual's natural skin tone. This increased pigmentation is a common change during pregnancy, along with changes to the skin on the face and abdomen. These skin changes are largely attributed to elevated estrogen levels in the mother's bloodstream. The areola also contains small oil glands, known as the glands of Montgomery, which become more prominent during pregnancy.123