The pregnancy pine, which is more official called linea nigra, is the dark line that develops across your belly during pregnancy. It is possible the line may have previously been there, however, because it was so light in color it went unnoticed. Prior to pregnancy, if there is a line which is light or pale, it is called the linea alba (white line). It runs from your navel to the pubic bone. It darkens during pregnancy acquiring the name linea nigra (black line).
The pregnancy line is never really black, however, it is brownish and darker in color. It is usually about ¼ to ½ inch wide and stretches vertically down your belly from the pubis to the umbilicus. The pregnancy line, or linea nigra, usually grows darker as your pregnancy develops. Although it can show earlier, this pregnancy line typically becomes visible around the 5th month of pregnancy.
What Causes the Linea Nigra or Pregnancy Line?
The pregnancy line is a natural part of pregnancy. The specific cause of the linea nigra is unknown, but it is believed to be related to the changing hormones or the imbalance of hormones, as a result of your developing baby. One theory is that the melanocyte-stimulating hormone, created by the placenta, is the main contributing factor. This hormone is also believed to cause the darkening around the nipple of the breast.
What can you do to prevent the pregnancy line?
There is nothing you can do to prevent the pregnancy line. It is a natural part of pregnancy. The good news is that it usually lessens and fades away shortly after the birth of your baby.
Compiled from the following resources:
Johnson, Robert V. (Ed.). (1994). Mayo Clinic complete book of pregnancy & baby’s first year. New York, NY: William Morrow and Company, Inc.
Cunningham, F. Gary, Leveno, Kenneth J., et al (2005). Maternal Physiology in Williams Obstetrics 22nd edition (126). New York, NY: McGraw-Hill.