<P> Prenatal memory, also called fetal memory, is important for the development of memory in humans . Many factors can impair fetal memory and its functions, primarily maternal actions . There are multiple techniques available not only to demonstrate the existence of fetal memory but to measure it . Fetal memory is vulnerable to certain diseases so much so that exposure can permanently damage the development of the fetus and even terminate the pregnancy by aborting the fetus . Maternal nutrition and the avoidance of drugs, alcohol and other substances during all nine months of pregnancy (especially the critical period when the nervous system is developing) is important to the development of the fetus and its memory systems . The use of certain substances can entail long - term permanent effects on the fetus that can carry on throughout their lifespan . </P> <P> There is some evidence that fetal memory may begin within the second trimester after conception . Substantial evidence for fetal memories has been found at around 30 weeks after conception . Fetal memory is important for parental recognition, and facilitates the bond between child and parents . One of the most important types of memory is that which stores information contributing to the maternal bond between infant and mother . This form of memory is important for a type of development known as attachment . Fetal memory is thus critical to the survival of the fetus both prenatally (in the womb) and after birth as an infant . </P> <P> The Central Nervous System (CNS) and memory in the fetus develop from the ectoderm following fertilization via a process called neurulation . The ectoderm is the outermost layer of the embryo . This happens towards the end of the third week of gestation (time period when the embryo is carried in the women's uterus) and ends with the start of the development of the neural tube, an important structure crucial to development of the central nervous system . Some evidence suggests memory is actually responsible for carrying out the development of the CNS during neurulation . However, much more research needs to be done on this . Fetal memory and brain development can be impaired by a number of maternal implications . Rubella, intrauterine hypoxia and hypothyroidism are some of the more researched examples . Alcohol and other substances such as hard drugs can affect this process as well . </P>

When does the fetus begin to develop memory