Some lesbian couples also have their own biological children. To do this they may have artificial insemination. This is when sperm from a donor male is placed in a woman to make a pregnancy. Some lesbian women do this at home with a friend they choose to be the donor. However many may use "sperm banks". These are medical businesses that match couples who need donor sperm with men who will donate. Sometimes this is done "anonymously" which means the couple does not know the donor. Sometimes this is done with the donor known and even chosen by the couple.