Prepregnancy Risk Factors for Preterm Birth and the Role of Maternal Nativity in a Low-Income, Hispanic Population

The aim of this study was to assess potential prepregnancy risk factors for preterm birth in a low-income, Hispanic population in Southern California. Additionally, the study assessed whether the prevalence of preterm birth and any associations between risk factors and preterm birth differed between U.S.- and foreign-born mothers. The study sample included 1174 mothers participating in the Special Supplemental Nutrition Program for Women, Infants and Children (WIC) within 1 year postpartum, including an augment sample of mothers who delivered preterm. Maternal sociodemographic traits, prepregnancy health-related characteristics and behaviors, and birth outcomes were collected by telephone survey. Odds ratios for associations between risk factors and preterm birth were estimated by logistic regression with sampling weights. Effect measure modification of any association by maternal nativity was also assessed using interaction terms. After adjustment for confounding, significant prepregnancy risk factors for preterm birth included maternal age a parts per thousand yen35 years (OR 2.00; 95 % CI 1.04, 3.84) compared to age 18-24 years, and experience of a financially stressful life event among U.S.-born, but not foreign-born, women (OR 2.61; 95 % CI 1.43, 4.77). The weighted prevalence of preterm birth was 15.1 % and did not significantly differ by maternal nativity (P = 0.19). Further investigation with large, prospective studies is needed to better understand the risk factors for and disparities in preterm birth among the growing Hispanic population in the U.S. so that women who are at risk prepregnancy can be identified and provided risk-specific services.