Impact of perceived stress, major life events and pregnancy attitudes on low birth weight

Context: While low birth weight is the leading cause of infant mortality an d morbidity, the factors influencing low birth weight are not well understo od In particular the relationship between stressful life events and birth o utcomes is unclear. It is important for health care providers to better und erstand the impact of stress on health outcomes Methods: Data from a statewide case-control study of 2,378 Missouri mothers are used to examine the relationship of perceived stress, pregnancy attitu des and major life events as psychosocial risk factors on very low birth we ight(ie., birth weight lower than 1,500 g). Such births are contrasted with moderately low birth weight births (those weighing between 1,500 and 2,499 g) and normal-birth-weight infants (those weighing 2,500 g or more). A ste pwise logistic regression model is used to control for all study and contro l variables. Results: The risk of very low birth weight is one and one-half times greate r if the mother perceived that she "almost always" felt stress during her p regnancy. The regression model confirms that besides perceived stress, seve ral other factors are independently associated with an increased risk of ve ry low or moderately low birth weight. For example, getting back with a hus band or partner or experiencing a major injury, accident or illness were as sociated with an elevated risk of low birth weight (odds ratio, 1.7), as wa s pregnancy denial (1.4-1.6) and unhappiness about the pregnancy (1.3). On the other hand, a few factors (taking out a mortgage or loan, having a clos e relative die and having a mistimed pregnancy) appear to have reduced the odds of low birth weight (odds ratio, 0.5-0.8). Conclusions: interventions with pregnant women, especially those assessing perceived stress and attitudes toward the pregnancy, have the potential to improve pregnancy outcomes. Additional prospective research with pregnant w omen on the origins and effects of stress, including the biological effects of stress, is needed.