A study of multiple births among Kanuri women of north-eastern Nigeria
Mbajiorgu, F.E.; Asala, S.A.; Ejiwunmi, A.B.; Hamman, O.W.
Central African Journal of Medicine 43(2): 48-51
1997
ISSN/ISBN: 0008-9176 Document Number: 228191
Objectives: To examine maternal age, incidence, sex ratio and zygosity of multiple deliveries among Kanuri women of north-eastern Nigeria and record these as additional base line data to those obtained for their southern Nigerian and Caucasian counterparts. Design: Retrospective data concerning maternal age and types of multiple deliveries were obtained from maternity records of three Maiduguri hospitals over a period of 5.5 to 9.5 years. Setting: University of Maiduguri Teaching Hospital, Maiduguii Specialist Hospital, Maiduguri Nursing Home, and the Department of Human Anatomy of the University of Maiduguri, Nigeria. Subjects: Kanuri women who lived in Maiduguri and delivered their babies at the three hospitals, and the babies delivered by them. Main Outcome Measures: Age groups of the women, total number of deliveries by them, numbers of multiple births above three, triplets, monozygotic and dizygotic twins. Results: The peak age group when the majority of deliveries took place was 25 to 29 years. This is lower than those of southern Nigerian Yoruba and Igbo and Caucasian women. Triplet rate was 0.2 per 1000 maternities. Twinning rate was 21 per 1 000 maternities with a twin:singleton ratio of 1:47. 'Mere was no significant difference between the overall incidence of male/male, female/female and male/female twin pairs. The incidence of dizygotic twins was higher than that of monozygotic twins. With increasing maternal age above 30 years, the incidence of monozygotic twins decreased while that of dizygotic twins increased, resulting in a uniform incidence of twins for all maternal age groups. Conclusion: Earlier onset of maternities was observed among the Kanuris who also had a lower twinning rate than their southern Nigerian and Caucasian counterparts. Although monozygotic rate decreased as dizygotic rate increased with increasing maternal age, the twinning rate remained constant for all maternal age groups. The overall incidence of twin pairs was also constant. It is suggested that these findings may be influenced by dietary and genetic factors.