Small Vulnerable Newborns Among Venezuelan Immigrants in Colombia Between 2018 and 2022.

Small Vulnerable Newborns (SVNs)-including low birth weight (LBW), preterm birth (PB), and small for gestational age (SGA)-represent a major global concern, with 35.3 million cases reported in 2020. Despite the growing overlap between migration and perinatal health, evidence on birth outcomes among Venezuelan migrants in Colombia remains limited. This study examined the association between maternal nationality and the likelihood of SVN, LBW, and PB among live births in Colombia from 2018 to 2022. We conducted a cross-sectional analysis of 3,111,716 births using national vital statistics (DANE). The primary exposure was maternal nationality. Outcomes included LBW (< 2,500 g), PB (< 37 weeks), and the combined SVN indicator. Logistic regression models were adjusted for sociodemographic variables (maternal age, education, marital status, region, newborn sex, and year), followed by additional adjustment for maternal factors (parity, interbirth interval, multiple births). Interaction models were also developed between maternal origin and maternal education, marital status, region, and interbirth interval. After sociodemographic and maternal-factor adjustment, Venezuelan mothers had higher odds of SVN (OR: 1.18, 95% CI: 1.13-1.22), LBW (OR: 1.19, 95% CI: 1.15-1.24), and PB (OR 1.06, 95% CI: 1.02-1.10). Interaction analyses showed that associations varied across geographic, educational, and reproductive contexts. For SVN, differences emerged particularly among women with missing education, missing marital status, and shorter interbirth intervals. These findings highlight the vulnerability of migrant mothers and underscore the need for equity-oriented maternal and child health policies in host countries.