Animal models, in vitro systems, and computer models of human implantation, placentation, parturition, and preterm birth should be studied.
Simple genetic and more complex epigenetic causes of preterm birth should be studied.
Gene-environment interactions and environmental factors should be considered broadly to include the physical and social environments.
Biological targets and the mechanisms and biological markers of exposure to environmental pollutants should be studied.
The committee finds that psychosocial, behavioral, and sociodemographic risk factors for preterm birth tend to cooccur; and the potentially powerful and complex interactions among these factors have been under-studied. When they are studied independently, each of these risk factors tends to have a weak and inconsistent association with the risk of preterm birth. The committee acknowledges that with each additional potential interaction sought, the sample size required to retain an adequate statistical power to reveal meaningful differences increases.
Recommendation II-2: Study multiple risk factors to facilitate the modeling of the complex interactions associated with preterm birth. Public and private funding agencies should promote and researchers should conduct investigations of multiple risk factors for preterm birth simultaneously rather than investigations of the individual risk factors in isolation. These studies will facilitate the modeling of these complex interactions and aid with the development and evaluation of more refined interventions tailored to specific risk profiles.
Specifically, these studies should achieve the following:
Develop strong theoretical models of the pathways from psychosocial factors, including stress, social support, and other resilience factors, to preterm delivery as a basis for ongoing observational research. These frameworks should include plausible biological mechanisms. Comprehensive studies should include psychosocial, behavioral, medical, and biological data.
Incorporate understudied exposures, such as the characteristics of employment and work contexts, including work-related stress; the effects of domestic or personal violence during pregnancy; racism; and personal resources, such as optimism, mastery and control, and pregnancy intendedness. These studies should also investigate the potential interactions of these exposures with exposure to environmental toxicants.