Is it permissible to mention a pregnancy duration shorter than the natural one when asked by an airport employee to avoid preventing the wife from traveling, and the harm that would result from that?

Lying is forbidden and is only permitted out of necessity or need, and within the narrowest limits. It is permissible to use ma'areedh (equivocation/allusion) to achieve the purpose without outright lying. It has been reported in the hadith that lying is permissible in three cases: war, reconciling between people, and a man speaking to his wife. Some scholars view lying as permissible for anything that involves a benefit without harming others, and that every praiseworthy objective that cannot be achieved except through lying is permissible if the objective itself is permissible, and obligatory if it is obligatory. It is permissible for a person to lie to himself or to others if it does not involve harm to others and if it helps him attain his right.