The present invention discloses a pharmaceutical composition for treating a subject with immunological recurrent spontaneous abortion which comprises a therapeutically effective amount of a substance capable of lowering the in vivo level of antinuclear antibody. Particularly, the substance is chromosome No. 2 or fragment thereof containing fibronectin encoding gene derived from the spouse of said subject, or a mixture of chromosome No. 2 or fragment thereof containing fibronectin encoding gene derived from a plurality of males. The present invention also discloses a method for treating immunological recurrent spontaneous abortion.