There is increasing evidence that circumstances very early in our lives, and particularly during pregnancy, can affect our health for the remainder of life. Studies that have looked at this relationship have often used extreme situations, such as famines that occurred during wartime. Here we investigate whether less extreme situations during World War II also affected later-life mortality for cohorts born in Belgium, France, The Netherlands, and Norway. We argue that these occupied countries experienced a considerable deterioration in daily life situations and show that this resulted in strongly increased mortality rates and lower probabilities of survival until age 55 among civilian populations who had been prenatally exposed to wartime circumstances. However, this mortality effect among the prenatally exposed is entirely concentrated in the first years of life, particularly infanthood. Once we condition on having survived the first years of life, those who had been prenatally exposed do not have higher mortality rates. This suggests that "culling" is important and that effects found in earlier studies may have been biased downward substantially.