[Irregular antibody testing during pregnancy in Tunisia: clinical study of 5369 women]

To evaluate the prevalence of alloimmunization in women followed in an obstetrical environment in Tunisia, to identify the specificities of antibodies found and to determine factors that could influence the appearance of this immunization.

We proceeded to a retrospective analysis of search for irregular antibodies in women followed up in obstetrical environment over nine consecutive years (2000-2008). The panel was officially defined and produced by the Regional Centre for Blood Transfusion in Sfax (Tunisia).

Overall 5369 women benefited from 6575 antibody testing (average: 1.22; extremes: 1-14). The results were positive for 278 women (5.17 %), allowing to identify 216 antibodies or associations of antibodies. Among identified antibodies, those immune were found in 198 women. The rate of alloimmunization was 3.68 % (198/5369). The majority of the antibodies found was anti-Rh1, isolated or associated with another antibody, in 84.3 % of the total immunized women. The immunization of women according to the number of gestations showed a significant increasing rate ranging from 2.34 % for a first gestation to 5.27 % for four gestations or more. In addition, a significant difference was also noted between the rate of immunization in women who had received anti-Rh1 immunoglobulin and those who had not.

Anti-Rh1 immunization is the most frequent in the population of studied women. This could denote of an insufficiency in pregnancies follow-up and immunoprophylaxis protocols.