[Head circumference and brain development. Growth retardation during intrauterine malnutrition and catch-up growth mechanisms (author's transl)].

Today the close correlation between head circumference growth and brain development in the last weeks of gestation and in the first two years of life is no longer disputed. A recently developed formula even allows for calculations of brain weight based upon head circumference data. Between the ages of 32 postmenstrual weeks and six months after expected date of delivery there is a period of very rapid brain growth in which the weight of the brain quadruples. During this growth spurt there exists an increased vulnerability by unfavorable environmental conditions, such as malnutrition and psychosocial deprivation. The erroneous belief still being prevalent that the brain of the fetus and young infant is spared by malnutrition, can be looked upon as disproved by new research results. Severe malnutrition during the brain growth spurt is thought to be a very important non-genetic factor influencing the development of the central nervous system (CNS) and therewith intellectual performance. In the past a permanent growth retardation of head circumference and a reduced intellectual capacity usually was observed in small-for-gestational age infants (SGA). Nowadays, however, there can be found also proofs of successful catch-up growth of head circumference and normal intellectual development after early and high-energy postnatal feeding of SGA infants. The development of SGA infants of even very low birth weight can be supported in such a way that it takes a normal course by providing good environmental conditions, such as appropriate nutrition - especially during the early growth period - and a stimulating environment with abundant attention by the mother.