What is the only inhaled corticosteroid that is Pregnancy Category B?

Of the inhaled corticosteroids, budesonide is currently the only one that is category B.

The category assignment was based on the findings of a 1999 study of 2,014 records in the Swedish Medical Birth Registry, which showed no increased risk for congenital malformations, premature birth, low birth weight, C-section, stillbirth, or multiple births associated with the use of budesonide during pregnancy (Obstet. Gynecol. 93[3]:392-95, 1999).

Related:

Inhaled corticosteroids called top Tx option in pregnancy; moderate, persistent asthma. OB/GYN News, Sept 1, 2003 by Kerri Wachter.

Asthma and pregnancy. JACI, 2011.