Birth history as a predictor of adverse birth outcomes: Evidence from state vital statistics data

One of the most important predictors of preterm births (PTBs) or low-birth-weight births (LBWBs) is whether a mother has had a history of these birth outcomes. This study examined how different characterizations of birth history (e.g., any previous incidence of PTBs or LBWBs, immediate previous birth that was preterm or of low birth weight, and number of previous PTBs or LBWBs) were associated with PTBs or LBWBs. Based on birth records (n = 98,776) reported to the vital statistics electronic registration system in Nebraska from 2005 to 2014, mothers with a history of PTBs or LBWBs were more likely to have recurrences of these outcomes than those who did not have any history of PTBs or LBWBs. The adjusted odds ratios for recurrent PTBs ranged from 2.82 (95% CI: 2.62, 3.04) to 5.54 (95% CI: 4.67, 6.57) depending on how previous incidence of PTBs or LBWBs were characterized. The corresponding adjusted odds ratio for LBWBs ranged from 1.58 (95% CI: 1.43, 1.74) to 6.75 (95% CI: 4.96, 9.17). Relative to other measures used to characterize birth history, the use of number of previous PTBs or LBWBs allows for identifying mothers most vulnerable to recurrences of these birth outcomes. To help identify mothers at risk for future PTBs or LBWBs, it is beneficial to develop state-wide surveillance of reoccurrences for adverse birth outcomes which is feasible by integrating all separated birth records for the same mother using vital statistics data.