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Biomedical subjects

N C Myrianthopoulos

Publications and source records attributed to N C Myrianthopoulos.

At least 37 records · Page 2Linked to original sources
PubMed1978

The effects of chorion type on variation in IQ in the NCPP twin population.

The 7-year IQ scores (WISC) of 116 white and 143 black nonmalformed twins of known zygosity and placental type were ascertained from the NINCDS Collaborative Perinatal Project (NCPP). The type of chorion and zygosity had no significant effect on the mean IQ or among-pair variation. In white monozygotic twins, however, analysis of variance revealed a significantly greater within-pair mean square for dichorionic twins than monochorionic twins. On the other hand, the white dichorionic monozygotic (MZ) and dizygotic (DZ) within-pair mean squares were quite similar. These findings were not evident in blacks for either of the within-pair comparisons. In addition, estimates of genetic variance were dependent upon MZ chorion type in both races. These data suggest to us that (1) in white twin pairs dichorionic placentas are of greater influence than the similarity or dissimilarity of genomes with regard to intrapair IQ development, and (2) failure to consider chorion type may introduce a serious bias in the interpretation of genetic variance estimates of IQ variability.

Chorion↗
PubMed1976

Risks to the offspring of women treated with hydantoin anticonvulsants, with emphasis on the fetal hydantoin syndrome.

The fetal hydantoin syndrome is a variable pattern of altered growth and performance which includes unusual facies, distal phalangeal hyoplasia, and other defects occurring in some infants exposed in utero to hydantoins. A prospective study of 35 infants exposed prenatally to this class of anticonvulsants showed that 11% had sufficient features to be classified as having the fetal hydantoin syndrome. An additional 31% displayed some features compatible with the prenatal effects of hydantoins. A case-control study of 104 infants whose mothers received hydantoins during pregnancy supports these conclusions. Reduction of intellectual ability in infants with the fetal hydantoin syndrome is the area of greatest concern. Women being treated with hydantoin anticonvulsants should be told of the nature and magnitude of risks to the developing fetus before considering a pregnancy.

Abnormalities, Drug-Induced↗
PubMed1976

A case of conjoined twins.

Among 56,249 maternities in the Collaborative Perinatal Project, 615 were twin maternities. One of these resulted in stillborn thoracoomphalopagus MZ female twins with multiple cardiovascular, alimentary and other malformations. The case is of further interest in that the mother had a surgically removed brain tumor in childhood and exhibited neurological symptoms and bizarre behavior before and during pregnancy. Drugs and treatments which she received during pregnancy are not known to be teratogenic.

Female↗
PubMed1976

Congenital malformations in twins.

Among 1195 twins born in the Collaborative Perinatal Project, for whom information was available, 219 (18.33%) were found to have malformations, 179 (14.98%) single and 40 (3.35%) multiple. The frequency of malformations among twins was significantly higher than that among singletons from the same population, but the difference was entirely contributed by MZ twins. This holds true for both major and minor malformations. The frequency among Negro twins was higher than among white, and among male twins higher than among female. Twins had more malformations of the central nervous, musculoskeletal, ear, respiratory, cardiovascular, and alimentary systems and fewer malformations of the genitourinary and integumentary systems than singletons. In a significant number of cases when one twin of a pair had a malformation, the cotwin also had a malformation though not necessarily the same as that of the first twin.

Abnormalities, Multiple↗
PubMed1976

Intellectual development of twins -- comparison with singletons.

Analysis of mental and motor tests scores and intelligence test performance of twins born in the Collaborative Perinatal Project shows that twins perform more poorly than singletons from the same population and that the differences are greater in Negroes than in whites. The poor performance of twins relative to that of singletons is of complex etiology. It is partly due to poor prenatal environment, for twins brought up as singletons perform at the intelligence level of twins and not of singletons. It may also be partly due to the higher incidence of congenital malformations in twins, especially those of the central nervous system. But the performance of twins, relative to that of singletons, tends to improve as they get older, at least from 4 to 7 years, suggesting that prematurity is also a contributing factor, whose detrimental effects may be reversible.

Black People↗
PubMed1975

Congenital hypothyroidism--signs and symptoms in the newborn period.

Infants with athyrotic hypothyroidism usually manifest signs and symptoms of hypothyroidism prior to or during the period in the newborn nursery. These features are variable and include: prolonged gestation with large size at birth, large posterior fontanel, respiratory distress, hypothermia, peripheral cyanosis, hypoactivity, poor feeding, lag in onset of stooling, abdominal distension with vomiting, protracted icterus, and/or edema. Retrospective assessment of newborn nursery records of three infants from the Collaborative Perinatal Project who were subsequently found to have congenital hypothyroidism disclosed that they had six, eight, and nine, respectively, of these features while in the newborn nursery. Evaluation of newborn records on 12 other infants, often less complete, who were later found to have congenital hypothyroidism disclosed that each infant had from one to seven of these signs and symptoms, with an average of 3.2 per infant. Thus the most important period for clinical consideration of athyrotic hypothyroidism is in the newborn nursery to initiate early thyroid replacement therapy in affected infants.

Birth Weight↗
PubMed1975

Congenital malformations in twins: epidemiologic survey.

Among 1195 twins born in the Collaborative Perinatal Project, for whom information was available, 219 (18.33%) were found to have malformations, 179 (14.98%) single and 40 (3.35%) multiple. The frequency of malformations and malformed individuals was significantly higher in twins than in singletons from the same population but the difference was entirely contributed by MZ twins. This held true for both major and minor malformations. There was no significant difference in the frequency of multiple malformations. Negro twins were more frequently malformed than white, and male twins were more frequently malformed than female. Twins had a significant, more than two-fold, increase of cardiovascular and alimentary tract malformations, and smaller increases of central nervous system, musculoskeletal, ear, and respiratory malformations over singletons. Significantly increased among specific malformations were macrocephaly, encephalocele, cleft lip and palate, anomalies of the diaphragm, cardiac septal defects, tracheoesophageal fistula, malformations of the alimentary tract, inguinal and umbilical hernias, and cystic kidney. A significant increase of malformations in twins over singletons occurred only in live births who survived to one year. There was a small but not significant increase of malformations in twin fetal deaths and deaths beyond the neonatal period; but among neonatal deaths, twins were less frequently malformed than singletons. Monoamniotic twins had higher mortality, more complications of delivery, and significantly more congenital malformations than diamniotic twins. One of the 9 pairs of MA twins in the study was a conjoined thoracopagus twin pair with multiple cardiovascular, alimentary, and other malformations. The case is interesting because of the medical history of the mother before and during pregnancy, and its possible bearing on the cause of MZ twinning and of congenital malformations. There was no difference in the frequency of malformations among first- and second-born twins. Concordance rates were significantly higher among MZ than among DZ twins for any malformation as well as for the categories of major, minor, single and multiple malformations. In the majority of cases, the twins were concordant for the same malformation. Concordance rates of MZ twins were consistently higher than those of DZ for all systems, but the difference was significant only for the musculoskeletal system, comprising mostly clubfoot. Because of the small numbers involved, the results of the concordance analysis should be interpreted with caution.

Amnion↗
PubMed1975

Factors affecting risks of congenital malformations. I. Analysis of epidemiologic factors in congenital malformations. Report from the Collaborative Perinatal Project.

An analysis was made of over 30 demographic, biologic and medical variables in relation to risks of congenital malformations which occurred in the Collaborative Perinatal Project. The study population consisted of 46,689 single and multiple live births and fetal deaths about whom complete information was available on all study variables. Included in the analysis were 5 general malformation categories, 27 specific major, and 7 specific minor malformations. Several new associations were detected between epidemiologic factors and risks of specific malformations while other previously reported associations were confirmed by the present investigation. The analysis of general categories of malformations showed that multiple births had a higher frequency of major malformations than single births; whenever sex differences in incidence were noted, males, with few exceptions, had an excess of malformations over females; and maternal diabetes during pregnancy was associated with increased risk of major malformations in the fetus. Among specific findings of possible etiologic significance were that the risk for microcephaly was associated with infrequent prenatal visits and the presence of maternal hyperthyroidism; and unusually low weight gain and infrequent prenatal visits were associated with increased risk for lung hypoplasia. There was no significant effect of inbreeding of the fetus or mother on the risks of general or specific types of malformations. Anencephaly was more frequent among white than among Negro infants, whereas no difference in incidence was noted in spina bifida between the two racial groups. This finding points to an inconsistency in the hypothesis of common etiology for these malformations. Whites were also found to have significantly higher incidences over Negroes of pyloric stenosis, congenital dislocation of the hip, micrognathia, and pectus excavatum, while Negroes have higher incidences of metatarsus varus and inguinal hernia.

Cataract↗
PubMed1975

Factors affecting risks of congenital malformations. II. Effect of maternal diabetes on congenital malformations.

The effect of maternal diabetes on the risk of congenital malformations was investigated in 23,695 pregnancies of white mothers, inclucing 339 patients of the Joslin Clinic, and in 24,742 pregnancies of Negro mothers, drawn from the prospective Collaborative Perinatal Project. Of these, 372 mothers had gestational diabetes and 567 had overt diabetes (before and during pregnancy). Pregnancy outcomes studied included stillbirths and live births. Among core women (excluding the Joslin Clinic cases), the frequencies of diabetic pregnancies were 1.31% and 1.18% for white and Negro mothers, respectively; in both groups, approximately two thirds of these pregnancies had gestational diabetes. There was no increase in malformation risk in the pregnancies of mothers with gestational diabetes over that of nondiabetic mothers in either racial group. However, the risk of malformation for white mothers with overt diabetes was double that of nondiabetic mothers for both major and minor categories of malformations. The incidences of major and minor types of malformations in the pregnancies of white mothers with overt diabetes were 17.94% and 10.94%, respectively, compared to the corresponding incidences of 8.34% and 6.25% for the white nondiabetic group. In Negro mothers with overt diabetes, a smaller increase of risk was seen only in major malformations; the incidences were 13.64% and 8.45% for the diabetic and nondiabetic groups, respectively. The increased risks for malformations were distributed generally throughout the organ systems. Multiple malformations occurred more frequently in the overt diabetic than in the nondiabetic group, suggesting that maternal diabetes must act adversely an an early stage of fetal development. Two cases with the caudal regression syndrome were observed in children of diabetic mothers, whereas none was found among births from nondiabetic mothers. Insulin (or analog) therapy of diabetes neither decreased nor increased the risk of malformation in the fetus. However, duration of diabetes had a significant effect on the malformation risk: the longer the mother had the disease, the higher was the incidence of malformations in the fetus. Paternal diabetes did not contribute to increase in risk. These observations suggest that maternal diabetes per se, through its adverse effects on maternal metabolism, is the responsible factor for the increase of malformations in the offspring.

Central Nervous System↗
PubMed1970

Intellectual development of children from interracial matings.

Interracial offspring of white mothers obtained significantly higher IQ scores at 4 years of age than interracial offspring of Negro mothers, suggesting that environmental factors play an important role in the lower intellectual performance of Negro children.

Black or African American↗