Due to our increasing knowledge on the pathophysiological basis of autoimmunity and the development of combined medical-obstetric clinics, pregnancy is becoming common among women with systemic lupus erythematosus (SLE). However, whether lupus worsens during pregnancy continues to be a controversial issue. SLE assessment during pregnancy is sometimes difficult due to physiological changes during this period, and common tools for measuring lupus activity during pregnancy were not available until recently. Several lupus activity scales in common use have been adapted for pregnancy [systemic lupus erythematosus in pregnancy activity index (SLEPDAI), modified lupus activity measurement (m-SLAM) and lupus activity index in pregnancy (LAI-P)]. All of them take into account the influence of pregnancy on clinical manifestation and common biochemical tests. LAI-P also accounts for specific manifestations of antiphospholipid syndrome in order not to score them as due to SLE activity. LAI-P has recently been validated for use in SLE pregnancy and could be used in future studies. However, daily assessment and management of individual pregnant women with lupus still relies on the clinical skills of attending physicians.