Kidd blood group phenotypes among pregnant women in Sokoto, North Western Nigeria.

OBJECTIVE: To investigate the prevalence of Kidd antigens among pregnant women in Sokoto, North Western Nigeria.

METHODS: One hundred and sixty two pregnant women aged 18-45 years [mean age (27.19±4.72) years] attending antenatal clinic in Usmanu Danfodiyo University Teaching Hospital, Sokoto, were screened for the presence of Kidd blood group antigens using the conventional tube method and anti-Jka and Jkb reagents (Lorne Laboratories, UK).

RESULTS: Out of the 162 pregnant women tested, 82 (50.6%) were Hausa, 26 (16%) were Igbo, 23 (14.2%) were Fulani and 20 (12.3%) were Yoruba while the minority ethnic groups were 11 (6.8%). The distribution of Kidd antigen was compared based on the ethnic groups of subjects. Jka antigen was the highest among the Yoruba ethnic group (10.0%) followed by the Hausa ethnic group (7.31%). The prevalence of Jkb was highest among Hausa subjects (10.97%) followed by the Yoruba ethnic group (10.0%). Subjects were categorized based on parity. Majority of the subjects were multigravidae, 122 (75.3%) compared to primigravidae 40 (24.7%). Subjects were stratified based on trimester. A significant number of women were in the second trimester, 111 (68.5%) compared to the third trimester 38 (23.5%) and the first 13 (8.0%). The distribution of Kidd antigens among subjects studied indicated a prevalence of Jka, Jkb and Jk(a+b+) with 8 (4.9%), 13 (8.0%) and 0 (0.0%), respectively. A significant number of subject tested were negative for Kidd antigens. Of the 162 pregnant women tested, 154 (95.1%), 149 (75.3%) and 141 (87.04%) tested were negative for Jka, Jkb, and Jk(a-b-), respectively.

CONCLUSIONS: This study indicates that blood group antigens can be distributed differently within different nationalities. Kidd phenotypes observed among pregnant women in this study was similar to previous reports among blacks but at variance with report among Caucasians and Asians. We recommend that detailed routine phenotyping for all clinically significant red cell antigen including Kidd antigen being carried out routinely among all pregnant women in Nigeria. There is also the need to routinely screen all pregnant women for alloantibodies to facilitate the selection of antigen negative units for those with clinically significant alloantibodies who require a red cell transfusion. This can potentially optimise the obstetric management of haemolytic disease of foetus and newborn and prevent haemolytic transfusion reaction among pregnant women.