Is it permissible for a barren woman to leave her house during the 'iddah (waiting period) for widowhood?

A woman observing 'iddah (waiting period) must remain in the house where her husband left her until her 'iddah ends. She is not permitted to leave except out of necessity or for a need that no one else can fulfill for her. There is no difference in this regard between a barren woman and others, for 'iddah is not solely for ensuring non-pregnancy; it has other rulings as well.