Large breasts in a one-week-old female baby should be clarified if there is a nucleus in the breast. If there is indeed a breast nodule, also known as a nucleus, consider it a breast nodule stimulated by maternal estrogen that has not returned to normal estrogen levels. If a child still has a breast nodule at the age of two weeks or older, it is considered a pathological condition and is not considered to be caused by maternal estrogen stimulation. The occurrence of breast nodules in girls due to high maternal estrogen levels in the fetus and until two years after birth when estrogen levels have not decreased to normal levels, which usually completely subsides by the time they are two weeks old. If breast nodules are still present after the age of two weeks, consider peripheral estrogen level stimulation and congenital pituitary lesions resulting in abnormal estrogen secretion, which requires further detailed examination at the hospital.