Birth Defects
Centuries ago in the land of Judea the disciples asked a question, “Who did sin, this [blind] man, or his parents, that he was born blind?” A prevailing idea at that time was that some transgression lay at the foundation of all congenital disease. It is true that conditions classed as birth defects may be related to parental transgression.
Evidence implicating drugs (cocaine, crack, LSD, etc.) as the cause of many chromosome defects and genetically transmitted disease accumulates every year. Some pharmaceutical drugs affect the growing embryo during key developmental phases. They may result in deformities of the cranium, limbs, heart, kidneys, or sense organs.
Infectious diseases, such as syphilis, toxoplasmosis, and the cytomegalovirus can all produce serious damage to the unborn child. In order to understand genetic diseases let us now consider some methods by which information is passed to our offspring. In the nucleus of every cell lie specialized strands of nucleic acids called chromosomes.
In human cells there are twenty-three pairs of these. Men and women differ only in the presence or absence of a Y chromosome (male — XY) or a pair of X chromosomes (female — XX). During the division of nonreproductive cells (mitosis) the chromosomes divide and duplicate themselves, forming identical nuclei in the “daughter” cells.
When a reproductive cell divides, however, its chromosomes split and each resulting spermatozoa or ovum receives only one-half of each of the original twentythree pairs, or half the complement of the fertilized ovum. This process (meiosis), then, results in cell division without duplication of original chromosome pairs and prepares the mature sex cell for fertilization.
In the chromosome lie a vast number of possible combinations (genes), each of which has the capability of governing growth, determining protein structure, and individuality. These genes make up the chromosomes. They are able to start or stop protein synthesis, according to the need of the developing organism.
It is a marvel of genetic engineering to consider the possibilities. To produce a human being, while preserving perfect individuality and the near infinite variety of possibilities for facial appearance, height, bone structure, hair color, eye color, fingerprints is just amazing to our finite mind.
A whole new science of medical investigation has developed studying the influence of drugs and birth trauma on behavior. Many terms have been coined to describe these disorders of childhood, among them minimal brain dysfunction and hyperactivity.
It is known that birth trauma—a difficult delivery, the traumatic use of forceps, or other conditions which result in oxygen deprivation—may produce long-term effects on behavior. Maternal use of drugs such as tranquilizers, cocaine, LSD, marijuana, and particularly alcohol (also numerous other substances) can induce changes that affect a person’s learning ability for his lifetime.
Many children of school age are unable to concentrate, sit still, or adhere to the discipline of a schoolroom. Multitudes develop patterns of truancy, then in adolescence become social problems or delinquents. The habits picked up tend to perpetuate the maladjustments.
If pregnancy ensues, this antisocial pattern of behavior is reproduced. The science dealing with these problems is called behavioral teratology. Research in the field constitutes one of the most fascinating, yet ominous perspectives of medical investigation today.
Many defects in the external physical appearance are related to chromosomal defects. The Down’s syndrome, is one of these in which characteristic facial appearance and retardation are evident. Many years ago a tranquilizer called thalidomide was administered to mothers during pregnancy.
Complete or partial failure of development (phocomelia) of the hands, arms, or lower extremities resulted, creating thousands of permanently deformed babies from the simple taking of a nerve pill. Many drugs today have cautions against their use during pregnancy.
But more drugs than we suspect may actually affect the unborn child. Pregnancy in women who are addicted to narcotics or the heavy use of alcohol runs a very high risk of developmental birth defects. Infections in the early part or pregnancy, particularly the first trimester, may also produce deformities in the offspring.
German measles or rubella may cause a wide range of birth defects, depending on when the infection occurred. Cleft palate, harelip, congenital heart disease, cataracts, and deafness are some of the afflictions that may stem from prenatal viral illnesses.
A pregnant mother harboring syphilis germs may also cause deformities in her offspring with bowing of the legs, saddle nose, or characteristic chisel-like teeth. Nutritional deficiencies during pregnancy may result in congenital problems.
Certain developing nations, because of their cultural taboos, prevent a mother from obtaining adequate sunlight, calcium, or milk. Congenital rickets can then develop, with failure to produce normal bones. Fractures, with life-long changes in the ribs, legs, or other growing bones are common. Conditions such as these are largely preventable.
Congenital Heart Disease
Many babies are born with defects of the heart, traced to chromosome defects, maternal infections, or the use of toxic agents. Two types of heart disease are seen.
One is called cyanotic, because of the characteristic “blue baby” who has a dusky color to the lips, hands, or a general cyanosis. The most common of these is called the Tetralogy of Fallot, and includes four basic cardiac defects requiring specialized study for diagnosis.
A number of surgical procedures have been devised to correct the congenital defects of the heart, reducing the mortality and extending the life of otherwise doomed children, Noncyanotic heart disease such as ventricular or atrial septal defects and stenosis of the pulmonary valves describe defects in other parts of the heart.
These conditions create an extra burden for the heart and if severe, may result in heart failure. Patent ductus arteriosis is another condition in which a normal shunting mechanism present in fetal life fails to close after birth. Surgical operations are being refined to deal with these problems and correct them early, to permit normal growth and activity in the young child.
Visual Defects
A number of eye problems are seen in the newborn. The most serious is congenital blindness, usually caused by cataracts. This is most frequently an aftermath of German measles in early (the first trimester) pregnancy. Avoiding exposure to this condition during the first three months of pregnancy or the inoculation of women who have not had Rubella prior to the childbearing years is preventive.
Less common today is blindness stemming from the use of high doses of oxygen for the newborn. Retrolental fibroplasia is a problem that was associated with the high concentration of oxygen used in treating an infant suffering from hyaline membrane disease.
Modern pediatric care in a neonatal intensive care unit has greatly reduced the incidence of this serious, but usually preventable condition. More commonly seen are a number of eye muscle imbalances present from birth. Some of the eye muscle shortening, called strabismus or “squint” may correct itself during the childhood years, as the eyes are alternately patched or treated with special glasses.
The imbalance, which results in double vision, would eventually destroy the sight in one eye. It should be treated as early as possible with corrective surgery. This can be done successfully by most ophthalmologists and will preserve good binocular vision.
Hearing Impairment
Congenital deafness is very difficult to recognize in the newborn. A variety of causes are known, including heredity, drugs, and maternal infections. Deafness is a serious handicap that requires early recognition. Usually a mother notices that her child does not startle with the loud noises that arouse others.
Vocal sounds fail to elicit appropriate smiles, and the child does not turn to face the sound of singing or other normal stimuli. Special hearing tests must be given to determine the type of deafness. Treatment may require hearing aids and special education. Early instruction in sign language, lip reading, and enrollment in special schools for the handicapped enable these children to compensate well for their lack of the marvelous gift of hearing.
Cerebral Palsy
Also called spastic diplegia, cerebral palsy is a condition that usually results from oxygen deficiency during birth. The affected individual often has associated seizures and moderate to mild retardation. There may be a profound impairment in coordination, with inability to walk without “scissoring” in the lower extremities. Lack of hand coordination also may be evident,
In the most severe cases normal development is completely impossible. “Patterning,” the alternate repetitive movement of extremities in “crossed extensor” pattern (straightening out of one arm and the opposite leg) has been tried by devoted friends and family members to enable an affected individual to learn what otherwise would have come naturally.
Some cases of cardiac arrest during childhood have resulted in cerebral palsy. With adjustment for the milder handicaps, many children can be educated to enjoy life with some useful skill.
Convulsive Disorders
Seizures can likewise stem from the lack of oxygen during birth. Infections in the newborn period or congenital toxoplasmosis can also produce convulsions. Usually in the newborn period, the seizures are of the grand mal type.
The epileptic attack consists of characteristic violent jerking (tonic and clonic) convulsions, loss of sphincter control, and an aftermath of somnolence. During the seizure there is a tendency to bite the tongue or quit breathing for a brief period Fever may aggravate the tendency toward seizures.
These should be distinguished from a true convulsive disorder. The electroencephalogram (EEG) can be very helpful in diagnosing the type of seizure and instituting a proper treatment. The next chapter will describe some of these problems, with a few suggestions for home management.