Linolenic acid is an essential amino acid in the human body, the role of linolenic acid on the fetus is relatively large, mainly in the following points: 1, linolenic acid is an important nutrient needed for fetal growth and development, can promote fetal growth and development; 2, linolenic acid is an important component of the fetal brain nerve development, if the pregnant woman’s body linolenic acid is sufficient, it helps the fetal brain nerve development; 3 , linolenic acid on the fetal vision development also has a role in promoting, if the body linolenic acid content is insufficient, it may lead to fetal vision loss. Pregnant women should eat more fish and other foods during pregnancy, to a certain extent, can supplement the lack of linolenic acid, which helps the fetus to develop better, if the lack of linolenic acid in the body is serious, need to be supplemented under the guidance of a doctor.