The present study was designed to investigate the participation of sCD23 and TNF-alpha in pregnant women in the first trimester. One hundred and forty-one patients were enrolled in the study. Women were classified into two groups. Serum sCD23 and TNF-alpha were measured in 73 normal pregnant women in the first trimester (Group I) and in 68 women with spontaneous abortion (Group II). We found that the mean values of TNF-alpha levels were higher in women with normal pregnancy than in women with spontaneous abortion (p < 0.05), whereas sCD23 levels of women in group II did not differ statistically from the controls. These results sustain the opinion that women with spontaneous abortion seem to have reduced TNF-alpha levels. However, determination of these immunological parameters provides no useful clinical information about disease activity and management.