Infants on soy based formula have phyto-estrogen levels up to 22,000 times higher than cow milk based formula or breast milk.
(pubmed.ncbi.nlm.nih.gov)https://pubmed.ncbi.nlm.nih.gov/9217716/Circulating concentrations of isoflavones in the seven infants fed soy-based formula were 13000-22000 times higher than plasma oestradiol concentrations in early life, and may be sufficient to exert biological effects, whereas the contribution of isoflavones from breast-milk and cow-milk is negligible.