Fetal and postnatal growth Introduction From conception to fetal development, childhood and adolescence, many factors influence a child's growth. Over the course of his life, the child undergoes a notable transformation before reaching adulthood; this transformation involves not only physical growth and maturation, but also an incredible series of complex developmental events that impact each organ system and the child as a whole. Developmental phenomena can be important determinants of the young patient's response to the disease and its management. Furthermore, the normal characteristics of "growing up" are sometimes mistakenly interpreted as manifestations of illness, giving rise to unnecessary worries. In turn, disease states can alter the pace and nature of maturation and growth during childhood. Fetal Growth Factors Fetal growth and development are controlled by genetic and environmental factors. There is overwhelming evidence that the intrauterine environment largely determines the diversity of offspring after a normal pregnancy. This has led to the theory that fetal organs are "programmed" during pregnancy and that disturbances in a critical or sensitive period during development could lead to disorders after birth and even diseases that manifest themselves no earlier than adulthood ( Adzick, 1984). Especially organs such as the brain and kidneys, where neurogenesis and nephrogenesis only take place during fetal life, are believed to be vulnerable to developmental disorders. Since new neurons and glomeruli do not develop after birth, any disturbing influence on the brain and kidneys during development could have lifelong consequences. Important factors that negatively influence d...... middle of paper ......lative contributions of lung fluid and fetal respiratory movements. J Pediatr Surg 19(6): 658-665, 1984. Brace, RA Physiology of amniotic fluid volume regulation. Clin Obstet Gynecol 40:280-289, 1997. Hedriana, H.L., W.M. Gilbert, and R.A. Brace. Arginine vasopressin-induced changes in blood flow to the ovine chorion, amnion, and placenta during gestation. J Soc Gynecol Invest 4:203-208, 1997. Andrews, J., McGarry, J.M. A community study of smoking in pregnancy. Journal Of Obstetrics And Gynecology Of The British Commonwealth 79(12): 1057-1073, December 1972. Denson, R, Nanson, JL, Mcwatters, Ma. Hyperkinesis and maternal smoking. Canadian Psychiatric Association Journal 20(3): 183-187, April 1975. Kline, J., Stein, Z.A., Susser, M., Warburton, D. Smoking: a risk factor for miscarriage. New England Journal of Medicine 297(15): 793-796, October 13, 1977.