Specificity of the FTA-ABS and TPHA tests during pregnancy.

In order to determine whether pregnancy influences the specificity of the fluorescent treponemal antibody absorption (FTA-ABS) and Treponema palidum haemagglutination assay (TPHA) tests, these tests, together with the quantitative fluorescent treponemal antibody (FTA) and Venereal Disease Research Laboratory (VDRL) tests, were carried out simultaneously on 2000 pregnant women who attended for compulsory prenatal screening. In only one patient (0.05% of the total investigated) was a positive result to the TPHA test obtained, the specificity of which it was impossibile to confirm. The FTA-ABS test gave a weakly reactive result of the borderline type but this was found to be non-specific in only four (0.2%) patients. The results of our investigations showed that the specificity of the FTA-ABS and the TPHA tests performed on pregnant women did not differ from the specificity of these tests when carried out on other population groups.