Moderate intake of linolenic acid will not cause serious effects on the fetus, but if overconsumption, it may lead to intrauterine growth retardation, weight loss and other abnormalities, but also affect the normal development of fetal intelligence, mental retardation and other situations, so it should be used under the guidance of a doctor. Linolenic acid as an amino acid, in the body can not be synthesized autonomously, and usually only in linseed oil, walnuts, pupae, deep-sea fish, etc., a very small number of foods can be obtained. Linolenic acid can promote the absorption of protein, vitamins and trace elements, so moderate intake can promote fetal brain development, enhance memory, thinking and stress capacity. However, for pregnant women without specific diseases, additional supplementation of linolenic acid is usually not recommended, while for the presence of certain diseases such as choroid plexus cysts, severe malnutrition and other conditions, additional linolenic acid will be supplemented for treatment. The use of controlled intake under the guidance of a doctor, not arbitrarily increase or decrease the dosage to avoid excessive use of linolenic acid resulting in abnormal fetal development.