Fetal programming, also known as prenatal programming, is the theory that environmental cues experienced during fetal development play a seminal role in determining health trajectories across the lifespan. Three main forms of programming that occur due to changes in the maternal environment are: Changes in development that lead to greater disease risk; Genetic changes which alter disease risk; Epigenetic changes which alter disease risk of not only the child but also that of the next generation - i.e. after a famine, grandchildren of women who were pregnant during the famine, are born smaller than the normal size, despite nutritional deficiencies having been fulfilled. These changes in the maternal environmental can be due to nutritional alteration, hormonal fluctuations or exposure to toxins. History Dutch famine 1944–45 In 1944–45, the German blockade of the Netherlands led to a lack of food supplies, causing the Dutch famine of 1944–45. The famine caused severe malnutrition among the population, including women in various stages of pregnancy. The Dutch Famine Birth Cohort Study examined the impact of lack of nutrition on children born during or after this famine. It showed that over the course of their life, these children were at greater risk of diabetes, cardiovascular disease, obesity, and other non-communicable diseases. Barker hypothesis In the 1980s, David Barker began a research study on this topic. The Barker Hypothesis, or Thrifty phenotype, forms the basis for much of the research conducted on fetal programming. This hypothesis states that if the fetus is exposed to low nutrition, it will adapt to that particular environment. Nutrients are diverted towards the development of the heart, brain, and other essential organs of the fetus. The body also undergoes metabolic alterations that ensure survival in spite of low nutrition but may cause problems in situations with normal or high nutrition. This leads to increased risk of metabolic syndrome. Nutritional status The developing fetus forms an impression of the world into which it will be born via its mother's nutritional status. Its development is thus modulated to create the best chance of survival. However, excessive or insufficient nutrition in the mother can provoke maladaptive developmental responses in the fetus, which in turn manifest in the form of post-natal diseases. It is possible that this has such a profound effect on the fetus’ adult life that it can even outweigh lifestyle factors. Excessive nutrition Body mass index prior to pregnancy and weight gain