Chronic diseases are the main public health problem in Western countries. There are indications that these diseases originate in the womb. It is thought that undernutrition of the fetus during critical periods of development would lead to adaptations in the structure and physiology of the fetal body, and thereby increase the risk of diseases in later life. The Dutch famine--though a historical disaster--provides a unique opportunity to study effects of undernutrition during gestation in humans. This thesis describes the effects of prenatal exposure to the Dutch famine on health in later life. We found indications that undernutrition during gestation affects health in later life. The effects on undernutrition, however, depend upon its timing during gestation and the organs and systems developing during that critical time window. Furthermore, our findings suggest that maternal malnutrition during gestation may permanently affect adult health without affecting the size of the baby at birth. This may imply that adaptations that enable the fetus to continue to grow may nevertheless have adverse consequences of improved nutrition of pregnant women will be underestimated if these are solely based on the size of the baby at birth. Little is known about what an adequate diet for pregnant women might be. In general, women are especially receptive to advice about diet and lifestyle before and during a pregnancy. This should be exploited to improve the health of future generations.