when a muslim man is about to enter his wife, he should always say first:
bismillahi, allahumma jannibnaa ash-shaitaan, wa jannib
ash-shaitaan maa razaqtanna
[in the name of allah, o allah, keep us away from the devil, and keep the
devil away from that which you may grant us (ie. offspring).]
about this, the prophet said: "after that, if allah decrees that they will have a child, the devil will never be able to harm that child". [al-bukharee][1]
footnote: