WHY DO WOMEN HAVE RHEUMATIC DISEASE

If gonadal hormones are responsible for the female predominance (gende r discrepancy, sexual dimorphism) that characterizes most autoimmune r heumatic diseases, pregnancy should be a particularly vulnerable perio d for onset of new disease as well as for exacerbation of established disease. Currently available data support neither the contention: that pregnancy increases incidence nor that it worsens severity of the com mon illnesses. Moreover, many illnesses pathogenetically similar to rh eumatic diseases have the same hormonal background but are not charact erized by sexual dimorphism. In nonrheumatic sexually dimorphic illnes ses an environmental, behavioral, or genetic reason for gender discrep ancy is usually present. To explain sexual dimorphism in the autoimmun e rheumatic diseases, the fields of environmental, genetic, chromosoma l, and in utero sex differentiation need further exploration.