One of the strongest predictors of PB is gestational hypertension (or eclampsia). PB risk and gestational hypertension may be altered by maternal behavior, such as leisure-time physical activity (LTPA), and overall maternal health influences the likelihood of both outcomes occurring. Biological plausibility lies on the fact that hypertension conditions are potentially influenced by LTPA directly or indirectly (as in the relation between excessive gestational weight gain and physical activity). Also, there is evidence that mental health plays a role in the determination of PB and, although biased by cross-sectional nature of studies, literature shows that physical activity may influence positively psychological aspects during pregnancy.