Hair which we are commanded to remove or shorten. This is known as Sunan al-Fitrah, such as removing the pubic hairs, trimming the moustache and plucking the armpit hairs. That also includes shaving or cutting the hair of the head during Hajj or ‘Umrah.
To conclude, shaving the pubic hair is a recommended act except for the wife if her husband orders her to do so, or she becomes odd to an extent that her husband is driven away from her, in which case it becomes an obligation on her to shave it.
"Five are among the Fitrah acts (i.e. natural disposition): Circumcision, shaving pubic hair, plucking out armpit hair, clipping one's nails and trimming one's moustache." [Al-Bukhaari and Muslim] The pubic hair could be removed by many means, but the Arabic word that is used is Istihdaad, which is using the iron i.e. a blade or a similar tool. Imaam An-Nawawi may Allaah have mercy upon him said: 'It is better to shave the pubic hair.'
Apparently there is a significant amount of concern in Islam about shaving hair, including pubic hair. Here are some of the more interesting comments.
As regards whether it is an obligation or optional, the jurists may Allaah have mercy upon them agreed that it is a recommended act for men and women, however, some jurists may Allaah have mercy upon them are of the view that it is an obligation on the woman if her husband orders her to do so.