Is the husband obligated to give a gift to both of his wives, or only to the wife who has given birth, upon childbirth?

Originally, the husband is not obligated to give a birth gift to the wife who has not given birth. It is sufficient for him to give it to her when she gives birth. Justice between wives is achieved by equality in giving at the time of birth for each of them. However, if the husband fears problems and wishes to give to both of them when one of them gives birth, then this is a recommended act to reconcile hearts.