It is very good to drink soy milk for pregnancy preparation because it contains special nutrients, namely soy isoflavones. Soy isoflavones are flavonoids that have a similar structure to estrogen, so they are also known as phytoestrogens, which can be regulated in both directions according to the level of estrogen in the body, and can play an estrogen-like effect when estrogen is not enough in the body. When there is an excess of estrogen, soy isoflavones play an anti-hormonal role. Estrogen plays a very important role for mothers preparing for pregnancy, and if estrogen levels are abnormal, such as high or low, it will have a direct impact on the outcome of pregnancy preparation. If a pregnant mother has gastrointestinal disease, gout, or stones, it is less suitable to drink soy milk.