It is recommended that pregnant women begin to supplement DHA after 20 weeks of pregnancy, supplementation until 6 months after the birth of the fetus is the best effect, pregnant women need to supplement a variety of nutrients during pregnancy, the needs of different nutrients are different, to understand the timing and needs of supplementation, in order to avoid the situation of excess nutrition. After 20 weeks of pregnancy is the stage of fetal brain development, after the birth of the fetus the mother can continue to take DHA and feed it to the fetus through breast milk. Pregnant women who want to fully absorb DHA need to eat moderate amounts of protein-rich foods such as eggs and fish in their diet. Pregnant women should not rely on nutritional supplements during pregnancy, but should mainly take all kinds of nutrients required by their body from their diet. Excessive supplementation of DHA can have corresponding side effects, such as causing a low immune system in pregnant women, so the amount of DHA supplementation should be reasonably controlled.