| During the normal development of the individual | | | | injury to the head. Premature infants are those |
| from conception to maturation, interruptions may | | | | born weighing less than 5 1/2 pounds. Babies |
| occur that result in retardation. These exogenous | | | | weighing about 3 pounds at birth stand a greater |
| causes will be discussed according to when they | | | | chance of developing more slowly and evidencing |
| occur-prenatal, perinatal, or postnatal. | | | | lower intellectual abilities. Anoxemia, or oxygen |
| The primary prenatal physical causes of | | | | deprivation, occurs when the placenta is blocked |
| retardation are infections and trauma. During the | | | | at birth or spontaneous breathing does not occur. |
| nine months of pregnancy the fetus develops | | | | In several studies with rhesus monkeys deprived |
| from one cell to a fully functioning body with a | | | | of oxygen at birth, up to 7 minutes of deprivation |
| brain and all organs in proper order. An interruption | | | | had no noticeable effect on later functioning. The |
| of this normal development affects the part of | | | | breech or transverse birth may increase the |
| the body that is growing at the time. Most | | | | possibility of suffocation, but the physician is |
| infections are prevented from reaching the fetus | | | | usually able to turn the baby properly. Direct |
| by the placenta. Rubella, or German measles, is | | | | trauma to the head may arise from a quick birth |
| the only acute infection commonly acquired during | | | | through a narrow cervical opening. Evidence is |
| pregnancy that is not blocked by the placenta. | | | | scanty for mechanical damage to the head using |
| This acute infection disrupts the normal | | | | forceps. It has been suggested that poorly |
| development and results in severe damage and | | | | adjusted mothers tend to blame the child's |
| deformity. In one study of 153 children whose | | | | problems on the birth process rather than seeing |
| mothers contracted rubella during pregnancy, | | | | them as a response to her or the family's |
| one-half evidenced borderline to severe mental | | | | tensions. |
| retardation. Deafness, blindness, and heart defects | | | | Postnatal hazards include head injury, asphyxiation, |
| are common. | | | | poisons, malnutrition, infections, and brain tumors. |
| Trauma includes drugs; maternal undernutrition; | | | | Automobile accidents and child abuse are the two |
| radiation; Rh blood incompatibility; chronic maternal | | | | most common causes of severe head injury in |
| infections such as certain viruses, bacteria, and | | | | young children. Meningitis, a viral inflammation of |
| protozoa; and various disorders such as maternal | | | | the brain's lining membrane, and high, persistent |
| anemia, high blood pressure, and diabetes. | | | | fever may affect the brain. These are treatable, |
| Treatment during pregnancy and at birth may | | | | and it is usually in severe cases that lingering |
| reduce the severity of effects in many of these | | | | effects will be noted. Asphyxiation may result in |
| cases. | | | | brain damage, depending on the length of time of |
| Perinatal problems, those occurring during the birth | | | | oxygen deprivation. |
| process, include prematurity, anoxemia, and direct | | | | |