Isolated pericardial effusion: an indication for fetal karyotyping?

The outcome and associations of 35 consecutive cases of isolated pericardial effusion detected in the fetus are presented. In all cases included in the study, there was no evidence of a structural abnormality or a rhythm disturbance detectable antenatally. Karyotyping revealed that 26% of cases had trisomy 21 and 31% of the total had some form of chromosomal anomaly. Our study shows that the outlook for isolated pericardial effusion is good. However, there is a high incidence of associated karyotypic anomalies, in particular trisomy 21. Fetal karyotyping is therefore recommended in these cases.

Fetal lung hyperechogenicity: prenatal ultrasonographic diagnosis, natural history and neonatal outcome

The ultrasonographic appearance of fetal lung hyperechogenicity is most commonly associated with congenital bronchopulmonary abnormalities, such as cystic adenomatoid malformation or pulmonary lobar sequestration. Spontaneous disappearance of echogenic lung lesions has rarely been reported, mainly due to in utero resolution of cystic adenomatoid malformation. We describe four fetuses with echogenic lungs detected prenatally, none of them having been proved to have adenomatoid malformation or pulmonary sequestration of the lungs. Color Doppler sonography was used prenatally in all cases to rule out pulmonary sequestration. Three of the four fetuses showed complete resolution of the lung lesions during gestation, with normal neonatal outcome, but in one where the lesion decreased in size, intrauterine demise occurred at 28 weeks' gestation before complete resolution, and pneumonia was found at autopsy. We suggest that fetal lung hyperechogenicity may result from in utero bronchial tree obstruction with retention of mucoid fluid distal to the obstruction. With advancing gestation, in some cases the relative obstruction may be relieved, and the sonographic appearance of the lungs may return to normal. A retention of mucus in the bronchial tree should be added to the differential diagnosis of hyperechogenic lung lesions detected by antenatal ultrasound examination.

Fetal pelvic kidney: a challenge in prenatal diagnosis?

The objective of this study was to establish ultrasonographic guidelines for the prenatal diagnosis of fetal pelvic kidneys and assess the relationship to clinical outcome. The records of all ultrasonographic diagnoses of a fetal pelvic kidney between 1 January 1991 and 31 December 1993 were reviewed. After review of the sonographic evaluation, the prenatal records were obtained, to assess demographic data as well as the obstetric course and neonatal outcome. If a fetal pelvic kidney was suspected on prenatal ultrasound examination, its precise location and size were recorded and compared with neonatal sonograms. Twenty-six cases of fetal ectopic kidney were diagnosed of which 13 were on the right side and 13 on the left (24/26 cases were diagnosed in the late second trimester). The size of the ectopic kidney did not differ from that of the normal kidney. Except for one case of hydronephrosis, there were no associated structural anomalies. All prenatal diagnoses were confirmed by postnatal sonograms and all neonates had normal renal function. Our conclusions are that prenatal sonographic detection of fetal pelvic kidney is feasible, although in most cases the diagnosis is made beyond 24 weeks' gestation. The importance of prenatal diagnosis is that the parents can be reassured that normal renal function is highly probable and that early neonatal intervention is usually unnecessary.

Natural history of trisomy 21 fetuses with increased nuchal translucency thickness

Increased fetal nuchal translucency thickness at 10-14 weeks of gestation can identify 80% of trisomy 21 pregnancies. However, a potential disadvantage of screening in the first trimester of pregnancy is that earlier screening preferentially identifies those chromosomally abnormal pregnancies that are destined to miscarry. In this study, we report on the outcome of six fetuses with increased nuchal translucency thickness and trisomy 21 whose parents chose to continue with the pregnancy. During the second trimester, the nuchal translucency resolved in five of the cases and in one it evolved into nuchal edema. Therefore, resolution of translucency with advancing gestation is not indicative of a normal karyotype. All pregnancies resulted in live births, suggesting that increased nuchal translucency does not necessarily identify those trisomic fetuses that are destined to die in utero.

Biometry of the fetal cisterna magna: estimates of the ability to detect trisomy 18

Measurements of the fetal cisterna magna were obtained from a prospective sample of patients undergoing diagnostic obstetric ultrasound examinations. These normal measurements were then compared to a retrospective sample of ultrasound scans from fetuses with the diagnosis of trisomy 18 by amniocentesis. The fetal cisterna magna increases in size throughout pregnancy. The sample from fetuses with trisomy 18 was different and had a higher rate of small and large cisterna magnas. After the two samples were mixed, it was determined that a cut-off of 2.5 standard deviations for the fetal cisterna magna would give a sensitivity of 26.3%, specificity of 99.1%, positive predictive value of 50.0% and negative predictive value of 97.6% for trisomy 18. The probability that a fetal cisterna magna of abnormal size will predict trisomy 18 in an early second-trimester ultrasound examination with the 2.5 standard deviation cut-off was estimated at 0.019. A fetal cisterna magna that is of abnormal size appears to be of diagnostic value in identifying the fetus with trisomy 18, but its sensitivity is low.

Developmental aspects of type II lissencephaly. Comparative study of dysplastic lesions in fetal and post-natal brains

We report neuropathological studies of five cases of type II lissencephaly from three fetuses and two infants. This comparative study allowed us to determine the developmental course of the cerebral lesions. Two distinct developmental events seem to generate this type of brain malformation: firstly, an early disturbance in cortex formation, which results both from a disorder of radial migration and a pial barrier disruption; secondly, a late perturbation of cerebral surface organization, resulting in fusion of the cerebral surface. All these features can be related to a primitive meningeal pathology, and more generally, to a neurocristopathy. Accordingly to our observations, this brain malformation appears during both migrational and post-migrational stages and may be considered more like a polymicrogyria than a lissencephaly.

In utero development of a mediastinal teratoma: a second-trimester event

Mediastinal teratomas have rarely been discovered during the prenatal period. When seen during the neonatal period, these tumours have caused respiratory distress or hydrops fetalis. We present the sonographic and pathological findings of a rapidly developing anterior mediastinal teratoma causing hydrops fetalis and in utero demise at 27 weeks' gestation.

Syndromes identified in fetuses with prenatally diagnosed cephaloceles

An evaluation of all fetuses from our institution with prenatally diagnosed cephaloceles was conducted to determine the frequency and spectrum of genetic syndromes associated with this abnormality. Review of the sonographic images, postnatal autopsy or pathology reports, delivery room records, paediatric neurosurgical findings, radiographs, and cytogenetic data were collected. Fifteen postnatally confirmed cases of prenatally diagnosed cephaloceles and two misdiagnosed cases were identified. Thirteen were midline occipital lesions, one was frontoparietal, and one was frontoethmoidal. Excluding microcephaly, hydrocephaly, and distortion of intracranial anatomy, 9 of 15 (60 per cent) had other associated anomalies, including two fetuses with aneuploidy. The prenatal diagnosis of a cephalocele should initiate a thorough search for other abnormalities. In this series, there were three multifactorial, two chromosomal, two sporadic, and two autosomal recessive syndromes identified. An accurate diagnosis is critical in determining the prognosis and providing appropriate genetic counselling.

Experience with 500 prenatal diagnoses of sickle cell diseases: the effect of gestational age on affected pregnancy outcome

Prenatal diagnosis of sickle cell diseases is obtained rapidly and precisely by polymerase chain reaction (PCR) with Ddel restriction analysis and dot-blotting with allele-specific oligonucleotides (ASO). Prenatal diagnosis of HgbSS and HgbSC was performed in 500 pregnancies, 196 by Southern blot and 304 by PCR. PCR drastically shortened the interval from sampling to reporting, allowing acceptance even of samples with unknown paternal phenotype, and resulted in an overall four-fold increase in diagnoses. In 108 pregnancies, the diagnosis was an affected fetus; 25 were HgbSC: 3 (12 per cent) were terminated; 83 were HgbSS: four ended in miscarriage; 40/79 (51 per cent) were terminated. The gestational age at the time of report to the mother appeared to be a major outcome determinant when the fetal diagnosis was HgbSS. The change-point in the maternal decision was found at 20 weeks of gestation. Before the 20th week, most mothers (64 per cent) chose termination; thereafter, the majority (72 per cent) chose continuation. The odds ratio of termination in earlier relative to later reporting was 4.7. In order to offer a choice to the mothers at risk of delivering a fetus affected by sickle cell disease, the diagnosis should be reported before the 20th week of gestation.

Prenatal sonographic diagnosis of a third ventricle choroid plexus papilloma

We report a case of fetal hydrocephalus secondary to a third ventricle choroid plexus papilloma detected by ultrasound at 33 weeks' gestation. The prenatal sonographic and colour flow Doppler findings of this rare fetal intracranial tumour are discussed.

[Morphological changes in the primordia of the deciduous teeth during an exacerbated course of the antenatal period]

Histologic examination of 380 rudimentary deciduous teeth of 91 stillborn babies or corpses of newborns dead within 16 days after birth and comparison of the results with clinical data brought the authors to a conclusion that the diagnosis of enamel hypoplasia is erroneous because all dental tissues are involved during this condition. Pathohistologic changes in the enamel, dentin, and tissues adjacent to dental rudiment are described in detail, all these tissues developing under unfavorable conditions of antenatal odontogenesis.

Fetus in fetu: molecular analysis of a fetiform mass

Fetus-in-fetu is a rare condition presenting as a calcified intra-abdominal mass in the newborn infant. Over 50 cases of fetus-in-fetu have been reported since 1800. Karyotype analysis in 8 cases and protein polymorphisms in 4 documented identical findings in the host and fetiform mass. We report a case of fetus-in-fetu in a newborn female including cytogenetic and molecular studies of both the host and mass. Genotypic information from 7 polymerase chain reaction (PCR) assays representing 4 chromosomes demonstrates heterozygous and identical alleles in the infant and fetus-in-fetu at all loci studied. A review of the literature is provided including a discussion regarding the impact of molecular data on present hypotheses of fetus-in-fetu pathogenesis.

Prenatal diagnosis of Charcot-Marie-Tooth disease type 1A by multicolor in situ hybridization

Genetic heterogeneity within the most common genetic neuropathy, Charcot-Marie-Tooth disease (CMT) results in about 70% slow nerve conduction CMT1 and 30% normal nerve conduction CMT2. Autosomal dominant CMT1A on chromosome 17p11.2 represents about 70% of CMT1 cases and about 50% of all CMT cases. Three different size CMT1A duplications with variable flanking breakpoints were characterized by multicolor in situ hybridization and confirmed by pulsed field gel electrophoresis and quantitative polymerase chain reaction (PCR) amplification. These different size duplications result in the same CMT1A phenotype confirming that trisomy of a normal gene region results in CMT1A. The smallest duplication does not include the 409 locus used previously to screen for CMT1A duplications. Direct analysis of interphase nuclei from fetuses and at-risk patients by multicolor in situ hybridization to a commonly duplicated CMT1A probe is informative more often than polymorphic PCR analysis, faster than pulsed field gel electrophoresis (PFGE), and faster, more informative, and more reliable than restriction enzyme analysis. CMT1B restriction enzyme analysis of CMT pedigrees without CMT1A is expected to diagnose another 8% of at-risk CMT1 patients (total: 78%).

Preimplantation prenatal diagnosis

Preimplantation prenatal diagnosis refers to the application of molecular genetic techniques to the assessment of gametes before conception or to early embryos before implantation. Such techniques could allow couples at significant risk for a variety of known genetic diseases to use assisted reproductive technology in achieving pregnancies that are free of the genetic disorder in question. The techniques, their risks, benefits, limitations, and potential applications are described, and recent experiences with human pregnancies are reviewed.

Congenital hepatic dysplasia from cytomegalovirus

The Authors report on a case of liver dysplasia in a four-month-old infant affected by prenatal cytomegalovirus infection. Immunologic, histologic and ultrastructural studies suggest an embryopathic origin of the lesions.

Collagen and elastin in the obstructed fetal bladder

Histological findings of muscle, collagen and elastin in obstructed fetal bladders were compared with those of age-matched controls. Muscle thickness was markedly increased, however, the relative collagen content in the muscle was decreased. The ratio of thick-to-thin collagen fibers was markedly increased as was the amount of elastin. These findings suggest that the ratio of thick collagen to elastin has an important role in determining the compliance of the obstructed fetal bladder.

Immunohistochemical studies show truncated dystrophins in the myotubes of three fetuses at risk for Duchenne muscular dystrophy

We have performed immunohistochemical studies on muscle tissue of three 12 week old fetuses at risk for DMD, using antisera directed against regions located NH2-proximally and centrally in the rod shaped spectrin-like domain and against the COOH-terminus of dystrophin. All three fetuses had a family history of DMD. Truncated dystrophins were identified in all three cases by a positive reaction with the NH2-proximal antibody, different reactions with the central antibody, and a negative reaction with the COOH-terminal antibody. These data indicate that a panel of antibodies would, in principle, permit 'immunological' mapping of dystrophin mutations. This is diagnostically important in the 35% of families where no mutation is detectable at the DNA level. Secondly, by using this mapping technique it may also become possible to identify the at risk haplotype when DNA analysis is not informative. This may be of great value in DMD carrier detection.

Experimental pestivirus infections in pregnant goats

Fifty pregnant goats, inoculated intramuscularly at different gestational stages with a non-cytopathic ovine pestivirus or a cytopathic bovine pestivirus, all developed pestivirus-neutralizing antibodies within 5 weeks of inoculation. The incidence of reproductive failure was similar for the two agents. Parturition at term with only healthy kids occurred in 13 (26 per cent) of the goats. Viable kids were not born to any of the 17 goats inoculated at about day 40 of gestation. Three of the 17 delivered dead or weak kids, seven aborted and three of seven which were necropsied during pregnancy had markedly underdeveloped and autolysed or mummified fetuses in utero, while four were barren. When inoculated at around the 60th day of gestation, two of 18 animals gave birth to only healthy kids, 12 to dead and/or weak kids, two aborted and, at necropsy, a small, decomposed fetus was found in one goat while one other was barren. In this group, one kid was ataxic and seven others had body tremors characteristic of border disease. One of the latter kids was viable. Of 15 goats inoculated at around day 100 of gestation, 11 gave birth to healthy kids only, three to dead and/or weak kids and one aborted. In 23 progeny, histological changes in the central nervous system (CNS) consisted mainly of cerebral white matter necrosis, cerebellar dysplasia, hypercellular areas in white matter and lymphocytic perivascular cuffings. All seven weak-born kids with signs of border disease had CNS lesions, particularly cerebellar dysplasia and/or hypercellular areas. Non-cytopathic pestivirus was isolated from tissues from all eight progeny examined in the 40-day inoculation group, from tissues and/or serum from 10 of 23 progeny in the 60-day group, and from four of 24 in the 100-day group. Persistent infection was demonstrated in a healthy kid, in a viable shaker and in two other kids which appeared normal at birth. Examination of offspring before ingestion of colostrum revealed pestivirus antibodies in one kid in each of the 40- and 60-day inoculation groups and in five kids in the 100-day group.

Effects of ethanol exposure on myelination and axon numbers in the L2 dorsal root of the neonatal rat

Previous studies have demonstrated that exposure to ethanol during development delays the rate at which axons in certain central nervous system tracts acquire myelin. This delay appears to be related to an alteration in oligodendrocyte function and not to an aberrancy in axon size or number. The present study was designed to determine if alterations similar to those observed in the central nervous system also occur in peripheral nerves, specifically the L2 dorsal root. Dams were fed either an ethanol-containing or control liquid diet 2 weeks prior to pregnancy and throughout gestation. The pups born to the pregnant dams were artificially reared from postnatal day (PD) 4 to PD 10 on a similar ethanol-containing or control diet. The pups were sacrificed on PD 10, L2 dorsal roots removed and processed for electron microscopy. The numbers of axons in various states of myelination were quantified. No difference was observed in the number of unmyelinated axons in the L2 dorsal roots from ethanol-exposed and control pups. In roots from ethanol-exposed pups, there was a significant decrease in the number of axons possessing myelin arranged in compact lamellae, but a significant increase in the number of axons surrounded by myelin lamellae in which the Schwann cell cytoplasm had not yet been extruded (noncompact). However, when the number of axons possessing noncompact myelin and a compact myelin sheath were summed, no significant difference was observed. These data suggest that the delay in myelination following ethanol exposure may be a ubiquitous phenomenon throughout the nervous system.

Chromosome analysis of postimplantation stage embryos for studying possible causes of developmental abnormalities in nonobese diabetic mice

The chromosomes of postimplantation stage embryos of nonobese diabetic (NOD) mice were analyzed to investigate the causal mechanism of congenital anomalies in diabetic pregnancies. Postimplantation stage embryos (day 12 of gestation) in diabetic (NOD-DM) and nondiabetic (NOD-N) NOD mice had either a high or low incidence of chromosomal abnormalities. A large majority of externally normal embryos from NOD-DM and NOD-N mice had low incidences. A high incidence of chromosomal abnormalities was found in externally abnormal embryos of NOD-DM and NOD-N mice, and in a smaller number of externally normal NOD-N and NOD-DM embryos. No control ICR embryo manifested a high incidence of chromosomal abnormalities. In the NOD-DM embryos, the chromosomes appeared to be influenced by long-term maternal diabetic conditions, while high incidences of chromosomal abnormalities in the NOD-N embryos suggested a probable cause by other factor(s) (e.g. a genetic predisposition) or by a very mild diabetic condition because the NOD-N mice were prediabetic.

Maternal hyperthermia as a cause of "idiopathic" mental retardation

Maternal hyperthermia of even short duration induces dramatic teratogenic (monster producing) effects in all experimental animals studied. In humans, several studies have reported cases analogous to some laboratory results in animal experiments, e.g., mental retardation, brain and nerve abnormalities and facial deformity. Recent computer-aided 3D reconstructions of pyramidal cells from guinea-pig brains subjected embryonically to a 1 hr stress at 44 degrees C environmental temperature, show that structural changes are induced in dendritic arbors. The alterations are greatest for dendritic segments closest to the cell body and are consistent with several reports linking topological and metrical anomalies with disturbances of brain function. We suggest that many cases of "idiopathic" subnormality are due to maternal hyperthermia during early pregnancy.

Binding of Ricinus communis I lectin to developing dystrophic muscle in human fetus

In previous studies it was shown that a D-galactose-specific lectin, Ricinus communis I (RCA I), does not bind to the plasma membrane of muscle fibres from patients with Duchenne muscular dystrophy (DMD) in contrast to normal muscle. We have now studied RCA I binding to the membranes of developing human fetal muscle in fetuses at 95% risk of DMD (n = 6) and normal controls (n = 5) with a developmental range of 12-20 weeks of gestation. The results were compared to the membrane appearance with conventional ultrastructure. Binding of RCA I to the muscle basement membrane was consistently strong from the early stages of myogenesis, such as in fusing myoblasts/myocytes. RCA I binding to the plasma membrane was weak but detectable in both DMD and normal fetuses at 12-14 weeks of gestation. Both the normal and diseased condition showed an increase of RCA I labelling of the muscle plasma membrane at 15-17 weeks and strong labelling at 18-20 weeks of gestation. No difference was observed in the RCA I localization of normal and diseased human fetal muscle plasma membrane. It is concluded that (a) the plasma membrane in developing fetal muscle undergoes a maturation process between 12 and 20 weeks gestational age leading to an increase in expression of RCA I binding carbohydrate moieties; and (b) that the absence of RCA I binding glycoprotein in mature DMD muscle plasma membrane reflects a change acquired during the course of disease.

Genetic prenatal aqueductal stenosis with hydrocephalus in rat

A recessive mutation which arose in Wistar albino rats was variably expressed in the homozygous state as prenatal stenosis of the aqueduct with resultant hydrocephalus. The condition was often compatible with survival to adulthood and with successful reproduction. Mildly sparse hair was the constant gene marker. Eye defects and sometimes foot deformities occurred. The first observable ultrastructural alteration was a disruption of the integrity of the neuroepithelial basal lamina in the cephalic neural tube of affected embryos as early as the 11th fetal day (16-24 somite pairs). The hydrocephalic syndrome closely resembled that produced by giving folic acid analogs to, or producing vitamin B12 deficiency in, pregnant rats in the period including the 11th day. Neither vitamin B12 nor folate, nor certain metabolites closely related to their metabolism, prevented the gene's expression. Homozygote mutants mated with homozygote mutants produced 70% hydrocephalic (dome-shaped heads) offspring, but if the mother was heterozygote, there was a "protective" effect and the number of hydrocephalic young was disproportionately smaller.

[Pathological and embryological studies on abortion cases related to the Seveso accident]

After the explosion accident on July 10, 1976 in Seveso (Italy), material from 30 interrupted pregnancies and from 4 spontaneous abortions was investigated by embryological and histomorphological studies. No indications of mutagenic, teratogenic or fetotoxic effects of TCDD could be found. The cases of spontaneous abortion, albeit more suspect for dioxin damage, showed different morphological alterations obviously due to a variety of causative factors independent of TCDD. On the other hand it is not possible to exclude entirely an embryotoxic effect of TCDD because in the majority of cases the fetal tissues were incomplete.

Developmental aspects of the pituitary-adrenal axis response to hemorrhagic stress in lamb fetuses in utero

Plasma ACTH and corticosteroid concentrations were measured by radioimmunoassay in chronically catheterized fetuses of 32 pregnant sheep. Fetal plasma ACTH levels 38+/-5 pg/ml (means+/-SEM) were slightly (P < 0.05) lower than maternal 54+/-4 pg/ml levels. No general rise in fetal plasma ACTH concentration was noted before 140 days gestation; however, fetal plasma corticoid levels began to increase after about 125 days. This suggested that an increase in fetal adrenal responsiveness to endogenous ACTH occurred during gestation. Hemorrhage of 15% of estimated blood volume decreased mean arterial pressure from 54+/-3 to 36+/-3 torr and increased plasma ACTH from 30+/-5 to 130+/-30 pg/ml in fetuses older than 0.80 gestation. In fetuses younger than 0.67 gestation, 15% hemorrhage caused no change in plasma ACTH levels despite a significant fall in mean arterial pressure. This suggests that system(s) subserving the ACTH response to mild hemorrhage are either absent or nonfunctional in the younger fetuses. The hemorrhage-induced increase in plasma ACTH levels was associated with a small rise in plasma corticoids in fetuses younger than 0.94 gestation. In older fetuses, a similar increase in plasma ACTH was associated with a pronounced increase in plasma corticoid levels. This also suggests that an increase in adrenal responsiveness to endogenous ACTH occurs during gestation. No detectable changes in maternal plasma ACTH or corticoids were found in response to fetal hemorrhage, thus the fetal pituitary-adrenal axis can autonomously respond to stress.

Genetical and embryological comparison of two mutations which cause foetal blebs in mice

Mutants with abnormalities which were the consequence of the formation of haematomas during gestation were designated as ‘foetal haematomata’ (fh). Thefhhomozygotes were found to be morphologically and embryologically very similar to myelencephalic bleb (my) mice. It was also found, however, that thefhandmymutants were separate genetic entities due to two independently segregating recessive genes.

Congenital anomalies of the umbilicus

Knowledge of the embryonic developments of the umbilicus and its contents assists the physician in correctly assessing the various anomalies found in this area. Although some will require specialized facilities and care, the majority of these anomalies can be corrected by simple operative means.