Factors associated with unfavorable birth outcomes: Findings from the 1996-2003 Mississippi linked birth and death data

Objectives. This study aimed to identify factors contributing to high rates of preterm birth (PTB), low birth weight (LBW) and infant mortality in Mississippi while considering both traditional risk factors and maternal medical conditions.

Methods. The retrospective cohort study used 1996-2003 Mississippi linked birth and infant death files. Multiple logistic regression was performed for the entire cohort and further stratified by race.

Overall Results. Along with traditional risk factors, e.g. no prenatal care and previous LBW infant, hypertension was a strong risk factor for both PTB (OR = 2.1, CI: 2.0-2.2) and LBW (OR = 3.2, CI: 3.1-3.4). Hydramnios/oligohydramnios placed women at a higher risk for LBW (OR = 3.1, CI: 2.8-3.4) and infant death (OR = 4.4, CI: 3.6-5.3). Non-Hispanic black women were more likely to have an unfavorable birth outcome compared to non-Hispanic white women in Mississippi, after controlling for all factors (p < 0.0001). Education level and marital status were not significantly associated with infant deaths among black mothers; furthermore the effect of maternal age and prenatal care appeared to be modified by maternal race.

Conclusions. Certain maternal medical conditions may be contributing to PTB, LBW and infant mortality rates. Earlier entry into prenatal care and preconception treatment of chronic disease are critical to reducing unfavorable outcomes. Our results suggest that different risk profiles for unfavorable outcomes may exist according to maternal race and underscore the need to further explore the sociodemographic and/or health-related factors that contribute to higher rates of unfavorable birth outcomes among minority women.