Autoimmune diseases are relatively common in women, and tend to occur in the childbearing years. These disorders fall broadly into two groups: (i) Multisystem diseases such as systemic lupus erythematosus (SLE) and related connective tissue disorders (CTD). This group includes the 'pre-clinical' antiphospholipid or lupus obstetric syndrome which may first manifest itself as a pregnancy disorder causing recurrent abortion, fetal death, fetal growth retardation and early onset severe pre-eclampsia. (ii) Tissue- or organ-specific disorders such as autoimmune thrombocytopaenic purpura (ATP), autoimmune thyroid disease (Graves' disease, Hashimoto's autoimmune thyroiditis, and post-postum thyroiditis), autoimmune haemolytic anaemia, and the very rare myasthenia gravis. The study of autoimmune diseases against the background of pregnancy as an experimental system of nature has provided important insights into the nature of the disease processes and the relevance or otherwise of circulating autoantibodies to pathological effects. Thus, for example, if neonatal manifestations of adult discase are causally related to the transfer of autoantibodies across the placenta, they will disappear over a time course consistent with the catabolism of IgG, providing no permanent damage is produced. Conversely, if autoantibodies are demonstrable in the neonate, in the absence of clinical effects, they may only be an epiphenomenon of the maternal disease. In addition, on occasions, disease manifestations may be seen in the baby when the mother shows none. This may occur when the mother is in remission, but still has circulating antibodies, or when she has an occult form of the disease. It is important also for clinicians to be aware of the reciprocal clinical effects in the mother of the disease-pregnancy relationship. In addition to their potential importance for the fetus and neonate, individual autoimmune diseases may dictate care and specific action in the management of pregnancies complicated by these disorders. Of a more general nature, however, are the possible effects of drug therapy where this is necessary during pregnancy complicated by autoimmune disease.
