Materials and Methods: A matched case-control study was conducted on 150 women with SPTB delivery and 150 women with spontaneous full-term delivery, in three hospitals in Riyadh. Cases and controls were matched in terms of age and parity. Then, information on maternal socio-economic risk factors was obtained through face-to-face interviews. The odds ratio (OR) for risk factors and a 95% confidence interval (CI) were calculated as well. Finally, a multiple logistic regression model was used to control potential confounding factors.

Results: Based on the results, factors including first-degree consanguinity (adjusted OR [AOR] =3.72, 95% CI=1.52-9.12), exposure to tobacco smoke (AOR=2.62, 95% CI=1.03-6.66), and low family income (AOR=4.63, 95% CI=1.62-13.27) were all associated with an increased risk of SPTB.

Conclusions: Overall, SPTB in Saudi Arabia was found to be correlated with first-degree consanguinity, low family income, and exposure to tobacco smoke. Therefore, public health interventions conducted to address these associated factors may contribute to the reduction in the prevalence of PTB.