Definition - What does Linea Nigra mean?
The linea nigra is a hyperpigmented line that develops on the belly during pregnancy. Usually ¼ to ½ inch wide, the line stretches vertically along the midline of the abdomen from the pubic bone to the top of the umbilicus, but it can extend to the sternum.
Fertilization triggers a cascade of events which eventually lead to the development of the placenta. Among its many functions, is to release hormones, some of which are responsible for the linea nigra.
The linea nigra is also known as the pregnancy line,
FertilitySmarts explains Linea Nigra
The linea nigra typically appears around the 5th month of pregnancy, but it can show up earlier. In many cases, the line gets darker as the pregnancy develops, and it is more commonly seen in people with darker complexions.
One theory is that the line’s appearance is caused by a hormone called the melanocyte-stimulating hormone which is made by the placenta. This same hormone is also believed to be responsible for the darkening of the nipples and melasma during pregnancy.
The other theory suggests that it is due to the larger amounts of estrogen and progesterone being produced. These two hormones stimulate the melanocytes in your skin causing them to produce more melanin which changes the color of the skin.
Before pregnancy, the line is known as the linea alba, but it is too light to be seen. The increased melanin production causes it to darken thereby becoming more visible. This line is seen in both sexes.
Many people have shared concerns about the pregnancy line, but it is a natural part of pregnancy, and it is not harmful. Some people believe, although it has not been proven, that it can be an indicator of the gender of the baby; girl if it reaches the belly button, and boy if it goes to your ribs.
The linea nigra usually fades away in the weeks to months following the birth of the baby. In some people, however, it may never completely disappear, and it can also reappear in subsequent pregnancies.