Moderating effect of social capital on income and oral health-related quality of life during pregnancy.

This cross-sectional study aimed to evaluate the moderating role of social capital in the relationship between income and oral health-related quality of life (OHRQoL) among pregnant women. The study was conducted using a random sample of pregnant women registered with the public health system in southern Brazil. Women with sensory or cognitive impairments, non-Brazilian nationality, or high-risk pregnancies were excluded. The Oral Health Impact Profile (OHIP-14) was used to assess OHRQoL. Social capital was evaluated through "perceived social support" and "pregnancy group attendance." The monthly household income was assessed in Brazilian Reais and categorized as either high (≥ 1,000 BRL) or low (< 1,000 BRL). The moderating role of social capital on the relationship between income and OHRQoL was tested using multilevel Poisson regression analysis. The results are presented as rate ratio (RR) with 95% confidence intervals (CI). A total of 520 pregnant women were assessed, with a response rate of 93%. Approximately 25.6% had low income. Both social capital variables demonstrated a moderating effect on the relationship between income and OHRQoL. Among pregnant women with a low household income, those without social support and those who did not attend pregnancy groups had 44% (RR = 1.44, 95%CI: 1.22-1.72) and 22% (RR = 1.22, 95%CI: 1.05-1.42) higher overall OHIP-14 scores, respectively, compared to their counterparts. This means that social support and group attendance substantially mitigate the negative effects of low income on OHRQoL. Our findings highlight the potential role of social capital promotion in this population.