Table 1.

Hypothesized mortality outcomes for varying conditions of in utero deprivation

	Effects of mortality selection on mortality after age 50
Effects of intrauterine programming on mortality after age 50	Weak: nutritional depletion not severe enough to select out the weakest members of the population	Strong: nutritional depletion leads to physiological damage severe enough to select out the weakest members of the population
Weak: nutritional depletion leads to minor physiological changes	Timing and duration of the exposure do not lead to physiological differences between the exposed and unexposed. The surviving population at age 50 is a heterogeneous group with little or no physiological change Hypothesis: no mortality differences	The exposure leads to selective attrition in utero and increased childhood and early adult mortality. The surviving population at age 50 is a robust group with little or no physiological change Hypothesis: lower mortality
Strong: nutritional depletion leads to physiological changes that alter the risk for mortality	The fetus adapts to an undernourished environment or is scarred by the exposure. The surviving population is a heterogeneous group with adaptive or mutagenic changes that decreases survival after age 50 Hypothesis: excess mortality	The in utero exposure to undernutrition causes the frail to die and leads to adaptation or scarring that alters mortality for the remaining cohort. This leads to a population of robust survivors with adaptive or mutagenic changes that decrease survival after age 50 Hypothesis: null or excess mortality