I 'm 48 years old. Now I have a seedling fibroid of size 11.2 x 8.5 in the anterior wall of uterus. What will be the treatment? Does it affect pregnanc

Not an issue. To answer your question, I need to make an assumption: The measurements you gave are in mm not cm. If this is true and it is in the wall of the uterus (rather than inside the uterine cavity) it should not affect your ability to get pregnant and doesn't require treatment. A bigger issue for you is that at age 48 it can be quite difficult to get pregnant even if nothing is wrong. Best wishes!