Only females have MC because the sex buds when the foetus was in the womb of the mother transformed into uterus and ovary. As we know the inner lining of uterus sheds itself and starts making another one. In boys the sex buds although transformed into male reproductive system it doesn't have to carry a child as it joins itself with the excretory system. if boys started having mc they will start passing blood even when they have to urinate
