If the father uses drugs does it effect the fetus?

No, absolutely not. Human sperm, while containing millions of genes that dictate the baby's characteristics, do not contain traces of substances such as drugs that may be present in a man's body. The true harm will come from a child being raised by a drug addicted father, but no, out of the womb the baby will not have any drugs from the father. However, the child's blood may contain traces of substances used by the mother during pregnancy.