摘要：Objectives. We used dynamical systems modeling to describe how a prenatal behavioral intervention that adapts to the needs of each pregnant woman may help manage gestational weight gain and alter the obesogenic intrauterine environment to regulate infant birth weight. Methods. This approach relies on integrating mechanistic energy balance, theory of planned behavior, and self-regulation models to describe how internal processes can be impacted by intervention dosages, and reinforce positive outcomes (e.g., healthy eating and physical activity) to moderate gestational weight gain and affect birth weight. Results. A simulated hypothetical case study from MATLAB with Simulink showed how, in response to our adaptive intervention, self-regulation helps adjust perceived behavioral control. This, in turn, changes the woman’s intention and behavior with respect to healthy eating and physical activity during pregnancy, affecting gestational weight gain and infant birth weight. Conclusions. This article demonstrates the potential for real-world applications of an adaptive intervention to manage gestational weight gain and moderate infant birth weight. This model could be expanded to examine the long-term sustainable impacts of an intervention that varies according to the participant’s needs on maternal postpartum weight retention and child postnatal eating behavior. Public health agencies 1,2 advocate preventive interventions among pregnant women, particularly overweight and obese pregnant women (OW/OBPW), to assist women in meeting the Institute of Medicine (IOM) gestational weight gain (GWG) guidelines in an effort to make a long-term impact on the obesity epidemic. Despite this recommendation, nearly 60% of OW/OBPW exceed GWG guidelines, 2 which has been shown to independently predict the onset of obesity, 2–4 type 2 diabetes, 5,6 and cardiovascular diseases 7 among women and their offspring. Thus, the prenatal period may be an opportune time to intervene and break the intergenerational cycle of obesity by reducing fetus exposure to an “obesogenic” intrauterine environment 8,9 through promoting maternal energy balance (EB). Although the underlying mechanism for how maternal prenatal obesity “programs” fetal development, related metabolic disorders, 10,11 and later obesity during childhood and adulthood 12–14 remains unclear, it is common to use high birth weight as a surrogate marker for intrauterine growth and as an indicator of the conditions experienced in utero. 15 Despite focused prevention efforts, behavioral intervention studies show little to no evidence for preventing excessive GWG among OW/OBPW. 16,17 Even more importantly, few, if any, existing GWG interventions have had an impact on rates of high infant birth weight. Thus, there is a critical need to develop effective and efficient interventions to prevent excessive maternal GWG and high infant birth weight. One potential reason for why GWG interventions have had some success among normal weight but not overweight women is that OW/OBPW may have unique barriers that require a higher intervention (i.e., more intensive) dosage to managing GWG than the single dose selected in interventions that rely on a “one size fits all” approach (i.e., fixed, time-invariant intervention). Another reason is that many factors influence GWG including behavioral (EB: energy intake [EI] and physical activity [PA]), psychological (attitude, perceived control, intention), sociodemographic (age, parity), and physical (body mass index [BMI], defined as weight in kilograms divided by the square of height in meters [kg/m2]; fat mass), 2 and thus, interventions are needed that consider how changes in these factors influence changes in GWG. A time-varying (i.e., “just-in-time”), individually tailored intervention that provides each woman, especially OW/OBPW, with the support needed to manage GWG and adapts to her unique needs over time across the pregnancy may be a promising approach to manage GWG and prevent high birth weight. This approach enhances potency and conserves resources (i.e., cost savings associated with delivering only necessary dosages to participants), and thus, it has the potential to increase compliance and improve effectiveness of treatment compared with fixed interventions that may or may not work for individuals depending on their needs. 18 We have developed the conceptual framework for such an intervention. Furthermore, we have used control systems engineering principles (in general) and dynamical modeling approaches (in particular) to inform our individually tailored, time-varying GWG intervention that uses decision algorithms (i.e., controllers that will assign the optimized intervention dosage) to increase intervention effectiveness and improve participant outcomes. 19,20 However, little is known about how our intervention (or any existing GWG intervention) affects infant birth weight. The goal of this study was to build on our existing research to discuss how our prenatal intervention not only helps women to manage their gestational weight gain, but also might alter the obesogenic fetus environment to regulate infant birth weight. A simulated hypothetical case study will be presented illustrating the basic workings of this model and demonstrating proof of concept for how self-regulation and adaptive interventions with decision rules influence GWG during pregnancy and, in turn, has an impact on infant birth weight. Exploratory simulations of our adaptive GWG intervention 21 will be generated from data based on an intergenerational fetal EB model 22 and artificial parameters to examine the effects of creating a healthy maternal–fetus eating and PA environment on infant birth weight.
