Consanguineous marriages in a Saudi population and the effect of inbreeding on prenatal and postnatal mortality

Abstract

Consanguineous marriages are strongly favoured in the Saudi population. A population-based study of consanguineous marriages was conducted in the Riyadh area. The prevalence rate of consanguineous marriages was 51.3% with an average inbreeding coefficient of 0.02265, which is high compared with many other countries. The most important variables affecting inbreeding were the regional background of the family (p < 0.001) and the level of education, which was inversely associated with consanguineous marriage (p < 0.001). Perinatal and postnatal mortalities were not significantly different between consanguineous and non-consanguineous families.

PIP: A total of 2001 married Saudis living in Riyadh (1365 women and 636 men aged 20-45 years) were included in this study carried out between January and June 1993. The proportion of subjects surveyed was based on the population of each district: North (19.6%), East (39.6%), South (20.6%), and West (20.1%). All eligible subjects were interviewed using a structured interview format in the district primary health centers and antenatal clinics. Data were collected on types of marriages and relationships of spouses, region of origin, the level of completed education, and fertility. Consanguinity was found in 1022 of the marriages (51.3%). Marriages between second cousins or closer relatives accounted for 41.1% of all unions. In another 10% of the marriages the women were married to a relative beyond the level of second cousin. The mean coefficient of inbreeding was 0.02265. 364 (63.0%) of 578 subjects who were either illiterate or had completed primary education only were married to a relative, compared with 658 (46%) of 1423 who had acquired higher education. The odds ratio was 1.98 (p 0.0001). There was a significant association between the level of education and consanguinity (p 0.001). The proportion of subjects married to relatives was highest in those from the southern region of the kingdom (69%) followed by those from the northern region (60%). The lowest frequency of consanguinity was found among those from the eastern region (41.5%). The abortion/miscarriage rate among women married to a second cousin or closer relative was 6.9% compared with 7.4% for nonconsanguineous marriages. The stillbirth rate was also comparable. Total prenatal losses were essentially the same among consanguineous (8.3%) and nonconsanguineous couples (8.9%). The rate of neonatal death and total postnatal fatality was 2.7% for consanguineous families and 2.2% for the nonconsanguineous group. Education programs should be established to increase awareness of the consequences of consanguineous mating, but without offending age-old traditional practices with their perceived social benefits. Genetic counseling and prenatal diagnosis should also be available for consanguineous couples.