Infant mortality is of great public health importance and its prevalence is often used as a summary indicator of a population's reproductive health status. Programmatic and policy focus on prematurity and birth weight stems largely from their known relationship to infant mortality and morbidity. A large body of literature exists linking poor gestational weight gain to prematurity and low birth weight, but its association with infant mortality is less well understood. Few nationally representative studies have examined infant death as an important pregnancy outcome of inadequate gestational weight gain and even fewer have explored its psychosocial and demographic correlates.

As a measure of healthy gestational weight gain, the Institute of Medicine (IOM) published guidelines which provide a recommended weight gain for each category of pre-pregnancy Body Mass Index (BMI). Informed by the Biomedical and Biopsychosocial models, this study examined the association between the IOM measure of inadequate gestational weight gain and risk of infant mortality by conducting secondary analyses of the 2005 Birth Cohort Linked Birth-Infant Death Data File (Cohort Linked File) and Phase 5 of the Pregnancy Risk Assessment Monitoring System (PRAMS). An analysis of 160,011 women who participated in PRAMS between 2004 and 2008 was used to replicate the IOM guidelines and examine the link between gestational weight gain and risks of infant mortality within four months of birth. The PRAMS dataset was also used to analyze the association between maternal pre-pregnancy BMI, weight gain, and infant death, as well as the influence of maternal stress on gestational weight gain. A separate analysis of 2,046,725 infants in the 2005 cohort linked file was conducted to quantify the risk of infant death associated with inadequate gestational weight gain as well as cause-specific mortality. Results from logistic and proportional hazards regression analyses suggest there is a substantial and significant association between inadequate gestational weight gain and infant death; however weight gain beyond the recommended amount may be protective. Inadequate gestational weight gain was associated with infant death from disorders relating to short gestation, fetal malnutrition, respiratory conditions, and birth defects. Receipt of adequate prenatal care was protective against inadequate gestational weight gain, but a positive association was not found between inadequate gestational weight gain and maternal stress. Implications for public health programs, policy, and future research are presented.