II. POINTS TO BE NOTED IN THE SECTION OF THE NEW-BORN.
Aside from establishing the cause of death, the autopsy of the new-born has for its aim the determination of the age of the infant, its viability and whether it was born living or dead. Special attention must therefore be paid to all points that may be of value in settling these questions.
The average length of a full-term new-born child is 50 cm. (42-58 cm.), boys being somewhat longer than girls; 58 cm. may be taken as the maximal length, 48 cm. the minimal. Both length and weight vary within wide limits. The length of the fetus in the first five months of intra-uterine life corresponds approximately to the square of the month. In the last five months the age of the fetus equals approximately the length in centimetres divided by five. Viability is usually regarded as beginning in the eighth month and with a body-length of over 32 cm. The average weight of the full-term new-born is 3,200 grms., for boys 3,310 grms., girls 3,230 grms.; maximum weight 5,500 grms., minimal 2,500. The weights for the different months are: second month, 4 grms., third month 5-20 grms., fourth 120 grms., fifth 284 grms., sixth 434 grms., seventh 1,218 grms., eighth 1,549 grms., ninth 1,971 grms., tenth 2,334 grms.
Look for traces of vernix cascosa. The skin of the well-nourished, full-term, new-born is smooth, not wrinkled, white or grayish-red rather than red in color (a slight icteric tint is so common as to be regarded as normal), and showing the fine lanugo hair only on the shoulders. The hair of the scalp averages 2-3 cm. in length. The finger-nails are firm, horny and extend beyond the finger-tips. The subcutaneous panniculus should be abundant. The average length of the umbilical cord is about 50 cm., and it is inserted about the middle of the body or just below it. As a rule it is thrown off on about the 5-6th day. The cartilages of the nose and ears are firm. In male infants the testicles lie in the firm and wrinkled scrotum (they begin to descend in the seventh month); in the female the outer labia usually meet, but occasionally the inner ones are visible. In the seventh and eighth months the clitoris rises above the greater labia. A small amount of blood-stained discharge is often present in the vagina of the new-born. From the mammæ of both male and female new-born a whitish turbid fluid (“Hexenmilch”) can usually be expressed. The great fontanel is 2-2.5 cm. broad, while the posterior one is nearly closed. The pupillary membrane is absent after the eighth month. The ductus arteriosus remains open 4-5 days after birth; the foramen ovale is not completely closed until the second or third month of extra-uterine life, although by the tenth day the opening is nearly obliterated. The center of ossification in the lower epiphysis of the femur should be present and measure 2-9 mm. It is not present in the eighth month and in a large proportion of cases begins to develop in the ninth month. Only rarely is it absent in normal full-term infants. It appears in the bluish-white cartilage as a lenticular mass of red or reddish-brown color in which the blood-vessels can be easily seen. It may be absent in congenital rachitis or syphilis, or in the latter disease it may show the characteristic appearance of osteochondritis syphilitica.
The head should be examined for the presence of the “head-tumor” or “caput succedaneum,” the œdematous swelling of the scalp over the parietal eminences. Minute hæmorrhages may be present in the tissues. The tumor usually grows smaller or disappears within 12-48 hours. In difficult labors a hœmatoma neonatorum may be produced between the periosteum and bone, usually over the right parietal eminence. It appears as a circumscribed tumor which may increase after birth and persists for a long time. As the result of a periostitis ossificans a wall of bone may be formed about the extravasate, or it may be encapsulated with small bony plates. After the absorption of the extravasate the newly-formed bone may persist throughout life in the form of a “crater-like” or “coral island” elevated circle of bone. Infection of the hæmatoma not infrequently leads to the formation of a subperiosteal abscess, purulent infiltration of the cranial bone and purulent meningitis. The cranium should also be carefully examined for other evidences of conditions due to the mechanism of birth, such as the general shape of the head, condition of sutures, movability of the cranial bones, depressions, over-lapping, etc., of the cranial bones. Wounds of the scalp and face should be carefully noted. The circumference of the cranium is 34.5 cm., sagittal diameter 10-13.5 cm., transverse 8-9.5 cm., diagonal 12-14 cm. The brain of the infant is normally rosy-red in color, rather translucent, soft, almost jelly-like, and moist. Tearing of the pial veins or meningeal arteries during delivery may produce fatal meningeal hæmorrhages.
The weights of the internal organs are: brain 380 grms., thymus 7-10 grms., heart 20.6 grms., lungs 58 grms., spleen 11.1 grms., kidneys together 23.6 grms., testicle 0.8 grm., liver 118 grms. The mature placenta weighs about 500 grms., and measures 15-20 cm. in diameter, 3 cm. thick in the middle and 0.5-1 cm. thick at the edge.
In the examination of the abdomen the color and appearance of the peritoneum, position of abdominal organs and height of diaphragm should be noted. Before respiration is established the diaphragm is at the fourth rib; after respiration is begun it is about one rib lower on both sides, usually a little lower on the left side than on the right. The condition of the umbilicus and umbilical vessels is of great importance (umbilical hæmorrhage, infection, insertion of cord, line of demarcation, etc.). Note contents, size of lumen, thickness and character of walls, appearance and moistness of intima. In umbilical infection the process spreads through the sheaths of the umbilical arteries rather than of the vein. The infected arteries contain yellowish-brown purulent thrombi; and the tissues about them show œdema, hæmorrhages, purulent infiltration or small abscesses. The perpendicular position of the stomach, the relatively large size of appendix to that of kidney and spleen, the lobulation of the kidneys, and the relatively large size of liver and adrenals must be borne in mind and not be regarded as pathologic. Examine adrenals especially for occurrence of hæemorrhage, infarction and thrombosis. Look for accessory adrenals (“adrenals of Marchand”) in broad ligament and along the spermatic cords. Thrombi in the renal and spermatic vessels are not rare in the new-born. Note occurrence and degree of uric-acid infarction of the kidneys (formerly supposed to indicate that child was born alive). Meconium is present in the large intestine of the child born at term; when prematurely born it is found only in the small intestine. It is greenish in color and contains cholesterin, crystals of calcium sulphate, bile-pigment, desquamated epithelium and granular detritus.
In the examination of the thorax especial attention should be paid to the thymus, noting its size, color, consistence and evidences of pressure upon underlying structures, particularly upon the trachea. In death from suffocation small petechiæ are often found in the thymus and in the serous membranes. The lungs rise up over the edges of the pericardium and thymus when respiration has occurred, and their color is a light rose. Areas of atelectasis are bluish. The unexpanded lungs are brownish-red, firm in consistence and distinctly lobulated. Air-containing lung floats in water and crepitates, and gives off bubbles when cut beneath the water. Attempts at artificial respiration may draw some air into the lungs. Gas-bubbles may be produced by decomposition. In white pneumonia the lung is pale, grayish-white and airless. The larynx, trachea and bronchi are to be examined for presence of mucus, amniotic fluid, meconium, foreign substances, etc. The ligated stomach should also be tested as to its floating power, and should be opened under water to determine the presence of air or gas.
The determination of the exact cause of death in the new-born is often very difficult or impossible. In many cases no adequate lesions can be found to explain the occurrence of sudden death in the first days or weeks after birth. Among the more frequent causes of such deaths are congenital syphilis, asphyxia neonatorum (cardiac syphilis, presence of amniotic fluid, etc., in respiratory passages, congenital cardiac lesions, injury to brain, meningeal or cerebral hæmorrhage, congenital marasmus, intra-uterine infections, umbilical infections, enlarged thymus, “overlying,” poisoning, congenital hæmophilia, melaena neonatorum, etc.), adrenal hæmorrhage, malformations of gastro-intestinal tract, absence of common duct, nephritis, pneumonia, etc. The most important congenital infections are syphilis, gonorrhœa, tuberculosis, variola, typhoid, pyogenic infection, tetanus, measles, scarlatina, influenza, meningitis, malaria, recurrent fever, pneumococcus, colon bacillus and others, mostly very rare. Congenital leukæmia has been observed. Numerous cases of congenital neoplasm have been reported (hæmangioma, lymphangioma, fibroma, lipoma, neurofibroma, papilloma of the larynx, adenoma, carcinoma [liver, kidneys, stomach, intestine], cystic tumors of liver, pancreas, kidneys and ovary, rhabdomyoma or rhabdomyosarcoma of kidney, heart, etc., adenosarcoma of kidney, dermoid cysts and various forms of teratomata).
Congenital syphilis is so common and such an important condition in the new-born that especial search should always be made for evidence of its presence. Smears of all the organs should be made in the cases examined soon after death, and either stained or examined at once by the dark-field method for the presence of the spirochæte. The most common anatomic manifestations of congenital syphilis are pemphigus, macules, papules, or maceration of the skin, white pneumonia, cardiac dilatation due to interstitial myocarditis, interstitial hepatitis, splenic enlargement and osteochondritis syphilitica. The long bones should always be examined for the last-named condition; they should be removed and cut longitudinally. In the boundary between epiphysis and diaphysis the presence of a yellow, hard zone points to this condition. The area of ossification is increased, irregular, and is separated from the bone by the yellowish zone, which in its earliest stages is soft and cellular, later sclerotic. The area of proliferating cartilage is also increased and may contain medullary spaces, showing as red lines. In rachitis the ossification-zone is wholly or partly wanting, while the zone of proliferating cartilage is broader and rich in red medullary spaces. In place of the ossification-zone there may be present a layer of soft, grayish-white osteoid tissue containing medullary spaces. No sharp line exists between the different zones.