Nebraska births between 1995 and 2005 were followed until 2018 to look for intergenerational associations of low birth weight (LBW) and preterm birth (PTB). Results from generalized estimating equations revealed that mothers born LBW preterm were more likely to deliver LBW (adjusted OR 1.94, 95% CI 1.39-2.71) or preterm (adjusted OR 1.65, 95% CI 1.20-2.27) than mothers born with normal weight or at term. In addition, mothers who had an LBW sibling were 44% more likely to have an LBW infant (OR 1.44, 95% CI 1.04-2.00). A consistent finding was also observed for mothers who had a PTB sibling (OR 1.47, 95% CI 1.10-1.95). Mothers who were LBW at birth or had any LBW siblings, especially two or more siblings, were more likely to repeat this adverse birth outcome. The same association was also observed in mothers who were born preterm.