When a baby is born he goes through the most abrupt, complete, and dramatic change of surroundings in his entire life. For nine months he has been living a parasitic existence within the warmth of the womb, but is suddenly thrust into a situation where he must behave as a separate, distinct individual capable of surviving under a wholly new set of conditions. This change requires a drastic adjustment, especially during the first fifteen to thirty minutes after birth (the partunate period), but extending well into the period of the neonate, or newborn, which covers the remainder of infancy.The change actually begins during the birth process rather than after birth has occurred. There are four types of birth: the normal, spontaneous, headfirst birth; the breech, or buttocks-first, birth; the crosswise, or transverse, presentation; and the Caesarean section in which the infant emerges through a slit made in the abdominal wall in order to avoid a difficult birth. But whatever the type of birth, the newborn infant must make several major adjustments as soon as his new life begins. He must adapt to a temperature of 70 degrees instead of 100 degrees, obtain oxygen by inhalation, take nourishment through his mouth, and eliminate waste products through the proper organs instead of through the cord and placenta. In view of these vast readjustments there is no wonder that the average baby loses weight and shows many signs of behavior disorganization for several days: he gasps, sneezes, coughs, and has trouble sucking and swallowing.There is considerable variation from infant to infant during the early adjustment period. Studies show that when a mother has gone through persistent emotional disturbances and stresses during the last months of pregnancy, her infant will tend to have a variety of difficulties: feeding problems, gastrointestinal dysfunctions, sleep problems, hyperactivity, and general irritability. As Sontag (1944) has put it, such an infant “has not had to wait until childhood for a bad home situation or other cause to make him neurotic. It was done for him before he even saw the light of day.”The type of birth experience may also have specific effects on the child. In most cases, infants born spontaneously make a quicker and more successful adjustment to the new environment than infants who have gone through a long and difficult labor (especially transverse and breech births), or infants born by Caesarean section. If the mother receives heavy doses of certain types of medication during the birth process, the infant may have trouble breathing and feeding during the first days of life. In addition, emotional tension on the part of the mother, due to fear of childbirth or resistance to having a child, may complicate the birth process and also, as noted above, hinder the infant’s adjustment to postnatal life.Even though birth is an ordeal and an entirely new environment must be faced immediately afterward, the baby usually makes a remarkably successful adjustment during the first few weeks of his life. Some infants, however, fail to make the grade and are either stillborn or succumb during the period of postnatal adjustment. The most critical BIRTH ORDER time is the day of birth itself, and the days that immediately follow; and the most common causes of death are prematurity, congenital debility, malformation, injury at birth, pneumonia, influenza, diabetes and anoxia (lack of oxygen due to excessive medication of the mother or strangulation by the umbilical cord during birth.)Surveys show that the mortality rate among neonates is higher among boys than among girls, among nonwhites than whites, and among infants from deprived environments than among those from privileged homes (due largely to inadequate maternal nutrition and medical care). It is also higher than average in cases where the mother has gone through an emotionally stressful pregnancy leading to a difflcult childbirth. See BIRTH TRAUMA.