The impact of socio-economic status on infant deaths: a case-control study from Istanbul

BACKGROUND: Socioeconomic disparities continue to impact child health. This study aimed to determine the association between socioeconomic status (SES) and infant mortality (IM) in a district in Istanbul. METHODS: This is a case-control study conducted in a district of Istanbul. The cases were all infants born alive who died before reaching the age of one between January 1, 2021, and December 31, 2022. The controls were randomly selected children who were born and survived their first year. The sample size was calculated as 83 cases and 166 controls assuming low SES doubled IM, with 80% power and an alpha error of 0.05. Data were obtained through health records and telephone interviews. SES was evaluated through a validated index that used parents’ education and occupation, households’ vehicles and ownership of electrical devices, house ownership, and the land value of the living area. SES was categorized into three groups: low, middle, and high. Logistic regression was used in the analysis. RESULTS: The response rate was 51.8%, with 42 cases and 87 controls. The multivariate model included mothers’ age, smoking status, presence of maternal chronic diseases and anemia, multiple gestations, antenatal visits (≥4 vs. <4), premature membrane rupture, mode of delivery, parental consanguinity, baby's gender, and the SES index. When high SES was the reference category, low (OR:4.34, 95%CI:1.18-15.92) and middle SES (OR:1.59, 95%CI:0.49-5.13) increased the risk of IM. Having <4 antenatal visits (OR:80.84, 95%CI:8.84-738.98), presence of maternal chronic diseases (OR:4.03, 95%CI:1.25-12.94), and anemia (OR:2.39 (95%CI: 0,86-6,64) also increased IM. CONCLUSIONS: Low SES continues to be the root cause of IM. Infants of mothers who had <4 antenatal visits, anemia, and chronic diseases were at increased risk for mortality. To address IM, it is essential to highlight why pregnant women underutilize antenatal care since these services are free. KEY MESSAGES: • Achieving equity should be the main target for decreasing infant mortality. • There is a need to address underutilization of antenatal services for decreasing infant mortality.