The black line of the stomach is the abdominal white line, is the structure of the human body is inherent, due to the melanin deposition in the pregnant woman’s body performance will be more obvious, and the birth of a boy or a girl has no relationship, and can not be through the stomach has a black line to judge the sex of the fetus. Women in pregnancy, due to increased secretion of melanocyte stimulating hormone, while a large number of estrogen and progesterone have melanocyte stimulating effect, the melanin in the pregnant woman’s body will increase, resulting in pregnant women abdominal white line, nipple, areola, vulva and other parts of the melanin deposits, pregnant women stomach will have a clear black line, this is a normal physiological changes in pregnant women, and the sex of the fetus has nothing to do. Pregnant women should maintain balanced and comprehensive nutrition after pregnancy to provide nutrition for the fetus. Pay attention to rest, maintain a good mood, do not care too much about the gender of the fetus, the health of the fetus is the most important.