If I am married but having another man's baby, is there any law about who is put on the baby's birth certificate?
I've heard that my husband would have to be put on the birth certificate as the father because we're married even though the baby's father is someone else.
Typically, if a child is born during a marriage then the husband is presumed to be the legal father. However, some states allow for a husband to sign an "Affidavit of Non-Paternity", and the biological father to sign an "Affidavit of Paternity". Other states provide that who ever's name is on the birth certificate makes them the "putative father" (the assumed father). All you do is to simply fill in actual father's information on the birth certificate, although this does not establish legal paternity (that can only be done via court proceedings and when you get a divorce).
To check on the law in IA, you should contact the Bureau of Vital Statistics or place a call into a family law attorney in your area.