This is a difficult subject to discuss with lay readers, for each prospective parent has a secret dread that his or her child may not be normal. Such fears cannot be helped; they distinguish the rational human from the irrational animal— it is unlikely that the pregnant bitch worries over the possibility that the pup she will whelp may be imperfect. Yet the worrying human prospective parent can gain assurance from the fact that 97 per cent of human progeny are perfect at birth. Of the 3 per cent which are imperfect, many have only such minor defects as hammer toe, extra digits, small appendages to the ear, birthmark, pilonidal sinus at the base of the spine, etc., so that they really need not be included in the category. A second source of solace is that many abnormalities which were very serious a few decades ago can be wholly eradicated by the miracles of modern medicine. A plaster cast applied within the first few days of life will straighten the club foot; the skillful use of the surgeon’s scalpel will eliminate even so grave a lesion as an abnormal opening between trachea and esophagus, to say nothing of all the fantastic procedures being successfully done to correct congenital abnormalities of the heart. A third source of comfort must be the realization that in this enlightened era few obstetricians are cruel enough to fan the spark of life in a hapless monster unless sincere religious conviction dictates such a conservative policy.
Occasionally the diagnosis of a fetal abnormality can be made prenatally. Hydrocephalus, ‘water on the brain,’ demonstrates itself by excessive size of the fetal head. This is suspected by the doctor on palpation. Anencephaly, the absence of much of the skull and brain, is suggested to the doctor by his failure to feel the firm, rounded head at either fetal pole. Both suspicions can be confirmed or refuted by X-ray. When a fetal defect is diagnosed that is incompatible with life, labor is induced as soon as is technically possible, to spare the weeks or months of unrewarding pregnancy which remain.
In truth little is known about the causes of congenital abnormalities. Some are unquestionably due to heredity, to genetic influences, such as hemophilia, the condition in which half the males bleed extravagantly from minor injuries and the females of the family transmit the defect. Others are due to environmental factors—such factors as German measles at an early stage of pregnancy or the application of ionizing radiation at critical periods of pregnancy by the use of therapeutic X-ray directly to the uterus, or a fallout from an atomic bomb when the pregnant woman is within three-quarters of a mile from the hypocenter. There is probably an intermediate group among whom the application of genetic influences is aided and abetted by environmental factors such as maternal age, which would explain why the fetal abnormality rate rises with maternal age.
A most interesting development has recently occurred in the field of congenital abnormalities. Through new laboratory techniques the chromosomes of each of us can be accurately counted and studied by processing a sample of blood or bone marrow. These studies include a pictograph, a graphic representation showing the form and structure of individual chromosomes. Normally, we possess twenty-two pairs of body chromosomes (autosomes) plus two paired sex chromosomes. In females, the two members of the sex pair look precisely alike, the XX combination. In males, the two members of the pair are unalike; one is large, an ‘X’ chromosome, the other small, a ‘Y’ chromosome.
About one newborn baby in every 600 has an abnormal chromosome pictograph, in most instances associated with a serious congenital abnormality. The type of abnormality is related to the particular chromosome pair involved and whether or not there are three chromosomes or one at the locus where normally there should be two. For example, trisomy (three chromosomes) at locus twenty-one is almost always associated with Mongolism. On the other hand, monosomy in the X chromosome pair, one X instead of two, is associated with Turner’s syndrome, a condition in which the woman has an absence of certain reproductive organs, rendering her sterile as well as giving her other physical stigmata, such as an extra skin fold in the neck and a strange carriage of the arms. Chromosome study is in its infancy, and its further development is certain to add much knowledge in the future. Perhaps some day the causes of trisomy and monosomy will be discovered, and, more important, their prevention.
The lay press has been flooded with a lot of sensational scare literature about the topic of congenital abnormalities. Much is largely conjecture and lacks proof. I have seen no proof that the minor amount of radiation to which ais exposed while the mother undergoes diagnostic (not therapeutic) X-ray has ever done harm. Despite the fact that abnormal mice can be created by exposing the pregnant mother to an atmosphere as rarefied as Mt. Everest for five hours, there is no proof that an airplane trip in a pressurized cabin during early pregnancy has ever damaged a human fetus.
If a doctor desired to be ultra-radical and employ every conceivable precaution to reduce the incidence of malformations, he would issue the following suggestions. First I mustthat today the wisdom of some remains uncertain. 1. Encourage small children to get German measles and probably mumps and chicken pox while in nursery or grammar school (to develop natural immunity). 2. Never give Rh-negative girls or women Rh-positive blood by either transfusion or injection. 3. Control diabetes carefully during pregnancy and avoid excessive quantities of insulin. 4. Be sure you and your husband are in your physical, nutritional, and reproductive prime before initiating a conception. 5. Avoid unnecessary diagnostic X-ray during pregnancy, especially to the pelvic region. Do not avoid essential X-ray. 6. When possible, substitute local anesthesia for general anesthesia in dental and surgical procedures during early pregnancy. Do not take gas alone as the general anesthetic. 7. If possible, avoid airplane travel until after the twelfth week, unless the plane is pressurized. 8. Whenever possible, have children while you and your husband are still young. 9. Do not take drugs unless prescribed by your doctor, and don’t ask for them unnecessarily.
The Likelihood of Repetition of a Congenital Defect
If the defect is not due to an environmental influence such as German measles or ionizing radiation, parents with one malformed offspring have a 5-per-cent average risk of a second malformed child. In half the cases such malformations duplicate the original one. With two malformed children, the risk of a third is increased to 15 to 25 per cent. However, since certain inherited defects have a particular pattern of repetition, it is wise to consult an expert in human genetics in the individual case. You may write to the Dight Institute, University of Minnesota, Minneapolis, Minnesota, a pre-eminent center.
At this point it is wise to introduce the pediatrician, a physician whose services are fully as essential to you as the obstetrician’s. In large maternities such as that at the Mount Sinai Hospital in New York, the newborn is the responsibility of the obstetrical staff until it leaves the delivery room, and from then on its medical needs and problems are taken over completely by pediatric colleagues. In private practice the patient’s family or her obstetrician notifies a pediatrician within the first twenty-four hours and invites him to come to the hospital and examine the baby, to meet and advise the new mother about nursing, the layette, and similar problems. When possible, choose a pediatric specialist if a competent one is available. Obviously he knows more about babies and children than most men in general practice, since he was specifically trained in this area. In case he does not arrive on time, I here give my views about the hospital care of the newborn, but if his views or advice differ from mine, by all means follow the guidance of the doctor who is going to take care of your baby at home.