Edith L. Potter

Bilateral renal agenesis

Summary Twenty instances of complete renal agenesis have been observed during a ten-year period among approximately 5,000 infants who were subjected to postmortem examination following intrauterine death or death in the neonatal period. There was no relation to maternal age or parity, method of delivery, or to complications of pregnancy. The infants were predominately males. The three female infants exhibited a complete absence of uterus and vagina. The lungs of all infants were hypoplastic and the faces of all infants showed a characteristic expression. Prior to post-mortem examination only eight infants were believed to have died because of malformations. The number of infants observed in this group of necropsies indicates that complete renal agenesis is not as rare as the small number of cases previously reported would indicate.

Twin zygosity and placental form in relation to the outcome of pregnancy

Abstract The zygosity of 80 per cent of 293 pairs of twins was established with certainty at birth; a placenta with a single chorion identified 22.8 per cent as monozygotic, differences in sex identified 30.2 per cent as dizygotic, and differences in blood groups of those of the same sex identified an additional 27.0 per cent as dizygotic. The remaining 20 per cent are probably although not positively monozygotic. The data corroborate Weinbergs rule which indicates the total number of dizygotic twins in any population should be twice the number of different sex and that this subtracted from the total should give the number who are monozygotic. Twins have a high mortality which in large measure is due to the high frequency of premature termination of pregnancy. Total neonatal mortality was seven times as great and fetal mortality three times as great for twins as for single infants. Neonatal deaths due primarily to premature delivery accounted for a mortality of 42.5 per 1,000 twin births and only 0.9 per 1,000 total births. However, among infants weighing 1,000 to 2,500 grams the perinatal mortality for twins was 10.5 per cent, for total infants it was 17.5 per cent. Twins known to be monozygous on the basis of monochorionic placentas, identical sex and blood groups had an increased frequency of premature delivery and consequently a greater mortality. Mortality was slightly higher for males (11.7 per cent) than females (9.4 per cent), for twins of like sex (12.2 per cent) than unlike sex (7.3 per cent), for second born (11.8 per cent) than first born (9.3 per cent), and for twins with monochorionic placentas (13.2 per cent) than dichorionic placentas (9.6 per cent). The only conditions that could be considered directly related to the fact of second birth were pneumonia and hyaline membrane disease. These were found in 5 first born and 13 second born. The difference in frequency of these 2 conditions made the only real difference in mortality of first and second twins as delivered at the Chicago Lying-in Hospital.The zygosity of 80 per cent of 293 pairs of twins was established with certainty at birth; a placenta with a single chorion identified 22.8 per cent as monozygotic, differences in sex identified 30.2 per cent as dizygotic, and differences in blood groups of those of the same sex identified an additional 27.0 per cent as dizygotic. The remaining 20 per cent are probably although not positively monozygotic. The data corroborate Weinbergs rule which indicates the total number of dizygotic twins in any population should be twice the number of different sex and that this subtracted from the total should give the number who are monozygotic. Twins have a high mortality which in large measure is due to the high frequency of premature termination of pregnancy. Total neonatal mortality was seven times as great and fetal mortality three times as great for twins as for single infants. Neonatal deaths due primarily to premature delivery accounted for a mortality of 42.5 per 1,000 twin births and only 0.9 per 1,000 total births. However, among infants weighing 1,000 to 2,500 grams the perinatal mortality for twins was 10.5 per cent, for total infants it was 17.5 per cent. Twins known to be monozygous on the basis of monochorionic placentas, identical sex and blood groups had an increased frequency of premature delivery and consequently a greater mortality. Mortality was slightly higher for males (11.7 per cent) than females (9.4 per cent), for twins of like sex (12.2 per cent) than unlike sex (7.3 per cent), for second born (11.8 per cent) than first born (9.3 per cent), and for twins with monochorionic placentas (13.2 per cent) than dichorionic placentas (9.6 per cent). The only conditions that could be considered directly related to the fact of second birth were pneumonia and hyaline membrane disease. These were found in 5 first born and 13 second born. The difference in frequency of these 2 conditions made the only real difference in mortality of first and second twins as delivered at the Chicago Lying-in Hospital.

Nuclear sex and genital malformation in 48 cases of renal agenesis, with especial reference to nonspecific female pseudohermaphroditism☆

Abstract In view of the frequent association of genital malformations and malformations of certain other organ systems, the discovery of one should invariably lead to an investigation of the possible presence of the other. Because of the close relationship of the urinary and genital systems in embryologic development and the marked preponderance of males among infants with complete bilateral renal agenesis, genital development and nuclear sex were studied in 48 fetuses and infants presenting this abnormality. The nuclear sex type was concordant with the external genital sex recorded at birth except in 4 cases which presented a special type of pseudohermaphroditism and were reported in detail. The final result of this study indicated that 13 infants were female, and 35 were male. The external genitals were often absent, malformed, or, in some females, markedly masculinized. In the female infants the internal genitals were invariably malformed. Twenty infants in the series presented anorectal malformations, 15 of them having an imperforate anus and an absence of the terminal portion of the intestine. The correlation with external genital malformation was striking. Seven of the 20 presented a sirenomelus malformation. A sharp distinction can be drawn between female pseudohermaphroditism with and without associated malformations. For the latter, apparently due to a single hormonal factor, the term “specific” is suggested, and for the former, apparently having a more complex etiology, the term “nonspecific” is proposed. This terminology has the advantage of stressing important clinical and theoretical differences. The cases of nonspecific pseudohermaphroditism found in the literature together with the 4 cases reported here make a total of 23. However, the syndrome is probably much more frequent than this would indicate. To appreciate its real incidence and its clinical variations, further study is needed.

Twin pregnancies in the service of the chicago lying-in hospital

Abstract Three hundred and thirty-four multiple pregnancies occurred in 31,131 total deliveries, an incidence of one in 93.4 for twins, and one in 15,514 for triplets. The average birth weight is 2,391 Gm. for an infant which is one of twins and 3,405 Gm. for other infants born in this hospital. The average length of gestation is 256 days in twin pregnancies, 281 days in all other pregnancies in this hospital. The combined fetal and neonatal death rate for 660 reportable twin infants is 13.3 per cent; for twin infants over 1,000 Gm. it is 8.4 per cent. The total hospital mortality for reportable births is 4.4 per cent. The incidence of hypertensive, pre-eclamptic and eclamptic toxemia among twins is more than three times that found in single pregnancies. Prematurity is the outstanding cause of death in twin infants. Maternal complications are probably not an important factor in producing fetal death. In this series the second born twin does not appear to have an increased birth hazard.

Yesterday and today.

Thirty-six years ago I began assembling material for what was to appear 5 years later as Pathology of the Fetus and Newborn. At that time little material was available relating to disease processes in what subsequently came to be called the perinatal period. What was known was widely scattered in many publications. It seemed, therefore, that it might be of help, not only to pathologists but also to obstetricians and pediatricians, if material pertaining to disease states in this age period could be made available in one place. Since excellent photographic facilities were available, much illustrative material had been accumulated that would provide visual evidence for many of the conditions discussed.

Clinical-pathological study of the infant and fetal mortality for a ten-year period at the chicago lying-in hospital☆

Abstract A summary of the probable causes of all stillbirths and infant deaths at the Chicago Lying-in Hospital for a ten-year period is found in Table III. Interference with the circulation of the fetus while it is still in utero appears to cause more deaths than any other condition. With death occurring before the onset of labor this is most commonly premature placental detachment; with death during labor it is most often cord prolapse or entanglement; and in death after birth it is most often placenta previa. In actual numbers premature placental detachment occurred with one and one-half times the frequency of the other conditions. Second in importance is prematurity, although it is highly probable that this should rank first because the combination of a harmful maternal complication and prematurity is doubtless more likely to result in a fatality after birth than would be the same complication acting on an infant at term. The fetuses who die before the onset of labor and the majority of those dying during labor cannot be considered to have died because of prematurity. The total number of prematures who die without specific lesions and whose deaths are probably due to inadequate development make up 25.6 per cent of deaths after birth, but only about 12 per cent of the total mortality. Birth trauma accounts for 13 per cent of the deaths. Included with the infants showing specific intracranial hemorrhage are 31 infants who either were not subjected to autopsy or who exhibited no gross bleeding, but in whom there was difficulty in effecting delivery or in whom there was clinical evidence of trauma in the infant after birth. Major malformations are almost equal to trauma as a cause of death. In deaths occurring in the neonatal period, malformations are second only to prematurity as a causative factor. Infections are not common during this period, and the few which are found consist almost entirely of pneumonia. Erythroblastosis, syphilis, and a few miscellaneous conditions make up the remainder of the conditions producing death.

Multiple pregnancies at the Chicago Lying-in Hospital, 1941 to 1947

Abstract In the six and one-half year period prior to July 1, 1947, there were 22,943 deliveries at the Chicago Lying-in Hospital. Among these there were 257 multiple pregnancies, an incidence of 1:91 for twins and 1:4,580 for triplets. The mean birth weight in this series was 2,354 Gm. The mean length of gestation for twin pregnancies was 256.7 days and for multiple pregnancies (including triplets) in which the combined weight of the babies was over 5,000 Gm. is 271.2 days. The mortality for all infants and fetuses weighing more than 1,000 Gm. was 8.2 per cent and for those over 2,500 Gm. was 1.6 per cent. The mortality for single infants born in this hospital during the same period was 2.5 per cent over 1,000 Gm. and 1.6 per cent over 2,500 Gm. The mean ratio between the weight of the placenta and the combined birth weight of the twins was 1:6.7, a ratio only slightly different from that of 1:7 found for single infants. The twins associated with 48 monochorionic placentas were of the same sex in 46; of different sexes in 2. Those associated with dichorionic placentas were of the same sex in 92, of different sexes in 70. The incidence of pre-eclamptic and hypertensive toxemia in this series was 21 per cent, in comparison to approximately 8 per cent for all deliveries. Postpartum hemorrhage and polyhydramnios also occurred more frequently than in single pregnancies. Prematurity was the most important cause of death in this series of twin infants. Polyhydramnios, placenta previa, and abruptio placentae were the maternal complications most commonly associated with fetal mortality.

The complications associated with excessive development of the human fetus

Abstract Among 20,219 births at the Chicago Lying-in Hospital 0.94 per cent of the infants weighed more than 4,500 gm. The average length of gesttion calculated fromthe first day of the last menstrual period ws 288 dys for these infants. The size of the fetus is lrgely dependent onthe length of gesttion, but size of the parents, multiparity, advancing age, or diabetes in the mother may be contributing factors in producing excessive development. Labor presents greater hazard for both mother and offspring when overdevelopment of the fetus has occurred. The necessity for operative interference is increased and the incidence of toxemia, of post-partum hemorrhage, of maternal morbidity, and of fetal mortality is definitely higher than when fetus is of smaller size. Accurate estimation of fetal size prior to deliver with consequent modification of the technique employed with decrease maternal complications and fetal mortality.

The importance of the Rh blood factor in erythroblastosis

Abstract Although 86 per cent of the population is Rh positive, isoagglutinins are not ordinarily present in the 14 per cent who are Rh negative (in contrast to the A and B antigens on which the main blood groups are based); in an individual who is Rh- (who does not naturally have the Rh antigen), agglutinins can be produced by the introduction of the Rh antigen into the blood stream. This introduction can be accomplished either by transfusion or by transfer, during pregnancy, of the Rh antigen from the fetal to the maternal circulation. When the mother is Rh- and the father is Rh+, either 50 or 100 per cent of the offspring will be Rh positive, the difference in percentage being dependent on whether the Rh factor in father is homo- or heterozygous. If fetal blood containing the Rh factor crosses the placental barrier and gains access to the maternal circulation, agglutinins may be produced in her blood. If agglutinins are produced either as a result of direct intentional transfusion or by occult transfusion from the fetus, the subsequent introduction of large amounts of blood containing the Rh antigen will result in the agglutination of this newly introduced blood and a fatal transfusion reaction may occur. When it becomes necessary to transfuse an infant suffering from erythroblastosis, the mothers blood should never be used. If, as we believe, the disease is due to the effect on the fetus of agglutinins transmitted to it from the maternal circulation, further introduction of maternal blood would result in the introduction of more agglutinins which would aggravate the disease. It has been contended that Rh negative blood should always be used to transfuse these infants because, in spite of the fact that they are practically always Rh positive, there is a possibility of free anti Rh agglutinins being present in their blood stream. We have not observed such agglutinins and have been unable to find a record of their demonstration. It may be questioned, therefore, whether it is necessary to transfuse with Rh negative blood on this basis. If cells and serum of patient and potential donor show no agglutination after incubation at 37°C. for one hour followed by centrifugation at 600 revolutions for one minute, the blood of this donor can be used with safety, regardless of whether it is Rh positive or Rh negative. Since the majority of women who give birth to babies with erythroblastosis are known to be Rh negative and may show anti-Rh agglutinins, it is essential to use blood from a known Rh negative donor if it becomes necessary to transfuse one of these women. Since the Rh factor is present in approximately 86 per cent of the general population, about 12 per cent of all marriages will be between couples where the wife is Rh negative, and the husband Rh positive. It is in this group that the wife is capable of becoming sensitized to the Rh factor and of subsequently reacting on the fetus to produce erythroblastosis. Erythroblastosis, however, occurs in only a small percentage of these women and in our experience has been found in only about 0.1 per cent of all pregnancies (The Chicago Lying-in Hospital). To account for the difference between potential and actual incidence, there are several conditions which may contribute: (1) in childless or one-child marriages the limitation in the number of offspring makes the production of erythroblastosis impossible, (2) the Rh antigen in the infant may vary in its ability to stimulate the production of agglutinins in the maternal blood, (3) the ability of the placenta to prevent the passage of the Rh antigen may vary, (4) the maternal response to the introduction of the Rh antigen into the blood stream may vary, (5) the ability of the placenta to permit passage of agglutinins may vary. It becomes apparent that although a fundamental incompatibility between the genetic constitution of the male and female germ cells may create a situation in which the occurrence of erythroblastosis becomes a possibility, there must be other superimposed factors which determine whether or not the possibility will be realized. A few women giving birth to babies who appear to suffer from erythroblastosis are Rh positive and a few infants suffering from the disease are Rh negative. It may be possible that these infants are actually suffering from a different disease entity. It is certain that severe jaundice or generalized edema can occur independently of erythroblastosis, and it is possible that in a small proportion of those infants who have the fundamental disturbance in the formation and destruction of erythrocytes which is usually characteristic of erythroblastosis, the condition may be a response to an ontirely different etiologic agent. Only further investigations can settle this point. It seems justifiable, however, to conclude that in any case where the diagnosis of erythroblastosis is doubtful, support for the diagnosis is obtained by finding the maternal blood Rh negative and the paternal and infant blood Rh positive. If the mother is Rh positive, the diagnosis of erythroblastosis is less probable.

Perinatal mortality: The Chicago Lying-in Hospital, 1931–1966

Abstract Perinatal mortality for 110,316 fetuses and infants weighing over 400 grams born at the Chicago Lying-in Hospital between May 31, 1931, and July 1, 1966, fell from 42 per 1,000 births in 1931–1941 to 29 per 1,000 births in 1961–1966. Mortality for live-born infants weighing over 1,000 grams decreased from 17.2 per 1,000 births to 8.6 per 1,000 births at the same time. The greatest reduction took place in the first half of this period with little change occurring since then. The decrease was due especially to a reduction in intracranial hemorrhage and intrauterine anoxia and its sequelae. In 1961–1966 the most common cause of perinatal mortality for fetuses and infants over 400 grams was intrauterine anoxia (6.1 per 1,000 births); for live-born infants over 2,500 grams the most common cause of death was malformations (1.0 per 1,000 births).