Infant with severe penicillamine embryopathy born to a woman with Wilson disease

We report a chromosomally normal infant boy with congenital diffuse cutis laxa, severe micrognathia, contractures of all limbs, and central nervous system abnormalities including agenesis of the corpus callosum, born to a woman taking D-penicillamine (DP) for Wilson disease (WD) throughout her pregnancy. His postnatal course was remarkable for chronic lung disease, profound developmental delays, and probable cortical blindness, as well as resolution of his cutis laxa. Embryopathy is a rare complication in babies born to pregnant women treated with DP, and there have been only seven previous reports of birth defects in exposed infants (three of which had favorable postnatal outcomes). The etiology of the severe outcome in this boy is unclear, but prenatal measurement of maternal copper and zinc levels may be indicated for management.

Three cases of tetrasomy 9p

We report three cases of tetrasomy 9p, two of which were confirmed prenatally. All three had characteristic findings on ultrasound and at birth. We also present a review of the literature, which suggests that a recognizable phenotype for this condition is emerging. Common findings on prenatal ultrasound include intrauterine growth restriction, ventriculomegaly, cleft lip or palate, and renal anomalies. These findings can provide a clue toward the prenatal diagnosis of this condition. There is also a clearly recognizable phenotype at birth. Facial characteristics include hypertelorism, broad nasal bridge/bulbous or beaked nose, cleft lip/palate, ear anomalies, and micrognathia. The exact extent of the isochromosome does not seem to predict severity, but mosaic cases are less severe, or at least have a greater probability of survival.

First-trimester trisomy screening: nuchal translucency measurement training and quality assurance to correct and unify technique

OBJECTIVE

To describe the process of training for measuring nuchal translucency at five clinical centers in North America and to evaluate methods of quality assurance and feedback.

DESIGN

Throughout a period of 18 months, the performance of sonographers in measuring fetal nuchal translucency was monitored using qualitative and quantitative methods of review. After 12 months, different approaches (written and personal feedback) were used to inform sonographers of technical aspects that needed to or could be improved.

RESULTS

On initial qualitative review, discrepancies in judgment from different reviewers coincided with suboptimal magnification, failure to visualize the amniotic membrane and/or use of cross-shaped calipers. At subsequent global review, 13 (29%) images of nuchal translucency measurements were considered unacceptable. Quantitative assessment revealed that, during the first part of the study, the means from four sonographers were significantly smaller and the mean from the fifth sonographer was significantly larger than expected on the basis of findings from The Fetal Medicine Foundation (P < 0.0001). Following feedback, sonographers who underestimated nuchal translucency and who received a written report only did not change measurements overall (P = 0.9759). In contrast, those who received additional intervention showed a marked difference (P < 0.0001).

CONCLUSIONS

Global qualitative review of images from one sonographer may be preferable to assessment of individual aspects of images. Results from global qualitative review correspond well with findings from quantitative analysis, indicating that the latter can be applied for ongoing audit. Observation of divergent results should prompt extensive personal feedback, rather than a written report, to prevent sonographers from settling in their own, inappropriate technique.

A novel X chromosome-linked genetic cause of recurrent spontaneous abortion

OBJECTIVE

Unexplained recurrent spontaneous abortion is a common women's health problem that affects approximately 1 of every 200 women who wish to have children. It has long been assumed that a large proportion of recurrent spontaneous abortion results from genetic problems, but no causative genes have been identified to date. Here, we tested the hypothesis that a subset of women with recurrent spontaneous abortion are carriers of X-linked recessive disorders that result in the loss of male pregnancies.

STUDY DESIGN

X chromosome inactivation patterns, an assay used to detect women who are likely to be carriers of X-linked recessive cell-lethal traits, were compared between 105 female patients with idiopathic recurrent pregnancy loss and 101 women (control subjects) with a single successful pregnancy and no history of pregnancy loss. Inheritance patterns and gender of offspring were studied in relevant subsets of participants.

RESULTS

Female patients showed a highly statistically significant increase in the frequency of skewed X chromosome inactivation (90%; P < .0005). Female patients with highly skewed X chromosome inactivation showed a significant decrease in male children. Four of 6 families that were studied showed maternal inheritance of the skewed inactivation trait.

CONCLUSION

We found the 14% of women with unexplained recurrent pregnancy loss show highly skewed X inactivation, which suggests that they are carriers of X-linked recessive lethal traits. Furthermore, the observed gender bias among women with highly skewed X inactivation suggests selective loss of male conceptions, which is consistent with an X chromosome-linked genetic defect that leads to cell death or growth disadvantage. Identification of such female carriers is important for the reproductive counseling and treatment of these women.

Maternal serum screening for fetal trisomy 18: benefits of patient-specific risk protocol

OBJECTIVE

Our goal was to evaluate the effectiveness of two approaches to screen pregnancies for trisomy 18.

STUDY DESIGN

We analyzed the outcome of all pregnancies that were screen positive for trisomy 18 by multiple marker screening (alpha-fetoprotein, unconjugated estriol, and human chorionic gonadotropin) from May 1993 to June 1998. We compared the results of a fixed cutoff protocol to a protocol that incorporates maternal age to generate a patient-specific risk figure.

RESULTS

A total of 45,145 patients were screened. By using the fixed cutoff protocol, 113 patients (0.25%) were screen positive. The risk-based approach was associated with a 0.55% screen-positive rate (250 patients). Eight of 12 cases (67% detection rate) of trisomy 18 were identified by using the risk method, and only 5 cases (42% detection rate) were detected by using the fixed cutoff method. By using the risk-based protocol, 21 pregnancies with chromosomal abnormalities (8, trisomy 18; 7, triploidy; 5, trisomy 21; and 1, mosaic 45X/46XX) were detected. Subsequent fetal death occurred for 42 patients whose fetuses were chromosomally normal and without structural malformations.

CONCLUSION

The patient-specific risk protocol to screen for trisomy 18 is a beneficial adjunct to screening programs already in place for Down syndrome and neural tube defects. Patients found to be screen positive for trisomy 18 are at significant risk for adverse pregnancy outcome.

X chromosome defects as an etiology of recurrent spontaneous abortion

Recurrent spontaneous abortion is a significant problem in women's health, yet it remains a poorly understood phenomenon. Many cases of recurrent spontaneous abortion defy diagnosis, and we predict that a subset of these unexplained cases are caused by previously unknown, recessively inherited genetic causes. Here, we provide background on known genetic factors that contribute to spontaneous abortion and describe a novel X chromosome-based genetic mechanism that may be an important cause of recurrent spontaneous abortion. Recessively inherited defects on the human X chromosome would cause no symptoms in carrier females but would be lethal in utero to male conceptions that receive the defective X. Through investigation of the basic biology of the X chromosome, we propose that the female carriers of such traits can be identified through the molecular finding of skewed X chromosome inactivation. Furthermore, we have observed an association between skewed X chromosome inactivation and recurrent pregnancy loss, supporting the hypothesis that X chromosome defects may be an important, previously unknown cause of recurrent pregnancy loss.

Second-trimester levels of maternal serum human chorionic gonadotropin and inhibin a as predictors of preeclampsia in the third trimester of pregnancy

OBJECTIVE

To determine whether second-trimester maternal serum levels of inhibin A, human chorionic gonadotropin (hCG), unconjugated estriol (uE3), and alpha-fetoprotein (AFP) are predictive of the later onset of preeclampsia in pregnancy.

METHODS

Retrospective evaluation of serum analyte levels in 60 women with preeclampsia compared with 300 controls. Levels of each analyte were compared in women with preeclampsia and controls using matched rank analysis. Analytes that were significantly different between groups were examined with univariate and bivariate Gaussian distribution analysis.

RESULTS

Second-trimester inhibin A (1.36 multiples of the median [MoM]) and hCG (1.40 MoM) levels were significantly but modestly elevated in women who later developed preeclampsia. A combination test of maternal age plus inhibin A and hCG predicted 23% of cases of preeclampsia with 95% specificity. There was a statistically significant trend for inhibin A, but not hCG, levels to be higher when the onset of preeclampsia occurred within a shorter (<17 weeks) interval after collection of the second-trimester screening sample.

CONCLUSIONS

Second-trimester serum levels of inhibin A and hCG are modest predictors of the later onset of preeclampsia. Inhibin A may be a better predictor of early-onset preeclampsia, which is associated with a higher maternal and perinatal morbidity and mortality, than preeclampsia at or near term.

Insights into the pathogenesis and natural history of fetuses with multicystic dysplastic kidney disease

To better delineate the natural history of multicystic displastic kidney disease (MCDKD) and provide insights into the pathogenesis of this condition, we report our experience in 102 prenatally detected cases. MCDKD is most commonly an incidental finding on prenatal ultrasound examination. The abnormality may be unilateral (76 per cent) or bilateral (24 per cent). In unilateral cases, abnormality of the contralateral kidney is common (33 per cent). Associated non-renal abnormalities occur frequently with both unilateral (26 per cent) and bilateral (67 per cent) MCDKD, and increase the risk for an abnormal chromosome study. Males are more likely to be affected than females with a ratio of 2.4:1, but females are twice as likely to have bilateral MCDKD and associated non-renal abnormalities, and four times more likely to have an abnormal chromosome study. We suggest that the option of chromosomal analysis should be discussed with all patients diagnosed with MCDKD in their fetus, if there is bilateral renal involvement or if an associated non-renal abnormality is present. Unilateral MCDKD without associated renal or non-renal abnormalities was not associated with an abnormal chromosome study, and resulted in favourable outcomes. While unilateral MCDKD, lack of associated anomalies, normal chromosome study and adequate amniotic fluid are all reassuring findings, a complete neonatal urologic work-up should be performed in all newborns. We believe the evaluation should include voiding cystourethrography to rule out vesicoureteral reflux. Our findings allow more precise counselling of patients regarding prognosis, and subsequent management of the fetus found to have MCDKD.

The use of interphase FISH for prenatal diagnosis of Pallister-Killian syndrome

Pallister-Killian syndrome (tetrasomy 12p) is a relatively rare aneuploidy syndrome characterized by the presence of mosaicism for an isochromosome 12p [i(12p)]. We report two new cases diagnosed following chorionic villus sampling and an abnormal ultrasound, respectively. Fluorescent in situ hybridization (FISH) was used to enumerate the number of interphase cells containing the isochromosome. The results of these studies illustrate the importance of the use of interphase FISH to detect the presence of the i(12p) in uncultured, non-dividing cells. A review of the literature identified 23 additional cases of Pallister-Killian syndrome diagnosed prenatally. Approximately 50 per cent of these cases were associated with the presence of a congenital diaphragmatic hernia. We suggest that a perinatal-lethal form of Pallister-Killian syndrome is underdiagnosed and recommend that all cases of prenatally detected diaphragmatic hernia be tested for Pallister-Killian syndrome using interphase FISH on uncultured amniocytes.

Choroid plexus cysts and trisomy 18: risk modification based on maternal age and multiple-marker screening

Choroid plexus cysts are more common in fetuses with chromosomal aneuploidies, particularly trisomy 18. Although it is accepted that the risk of karyotypic abnormality justifies amniocentesis when associated abnormalities are present, disagreement continues as to the risk of trisomy 18 in a fetus with an isolated choroid plexus cyst. We propose consideration of maternal age and multiple-marker screening for chromosomal aneuploidy in the assessment of risk. Bayesian statistical modeling was used to calculate the risk of trisomy 18 from age-related risk figures for trisomy 18 and the incidence of isolated choroid plexus cysts in fetuses with trisomy 18. The risk was further modified on the basis of the ability of multiple-marker screening to detect fetuses with trisomy 18. From risk estimates calculated across maternal ages 20 to 45 years, the risk of trisomy 18 does not approach that of amniocentesis until a maternal age of > or = 37 years. Therefore in the presence of an isolated choroid plexus cyst and normal multiple-marker screen results amniocentesis is justified only in the patient with advanced maternal age.

Preconception genetic counseling

The purpose of this chapter has not been to be all-inclusive, but to raise awareness of the benefits of preconception consultation in the prevention of birth defects. If there is to be a significant decrease in the incidence of congenital malformations, it will come only by intervention that occurs prior to organogenesis, and that opportunity is lost by the first prenatal visit. For the practitioner interested in a more in-depth analysis of the subject of preconception counseling, the two books listed as supplementary reading provide a wealth of information essential to the care of the patient planning a pregnancy.

45,X/46,XY mosaicism: the role of ultrasound in prenatal diagnosis and counselling

The purpose of this study was to assess the benefit of ultrasound evaluation for fetuses with prenatally diagnosed 45,X/46,XY mosaicism. The charts of all patients who underwent chorionic villus sampling and/or amniocentesis between 1 March 1990 and 31 October 1995 were screened for 45,X/46,XY mosaicism. Cases were divided on the basis of the results of the confirmatory amniocentesis into two groups: (1) confined placental mosaicism (n = 4); and (2) true fetal 45,X/46,XY mosaicism (n = 4). All patients underwent high-resolution detailed ultrasound study between 16 and 22 weeks. If the initial ultrasound study failed to visualize fetal genitalia, scanning was repeated in 2 weeks. Chromosome analysis was carried out on the newborn's skin to confirm the prenatal result. Six cases were found to have 45,X/46,XY mosaicism on chorionic villus sampling. Amniocentesis indicated a normal 46,XY male karyotype for three fetuses and true fetal 45,X/46,XY mosaicism for two cases. One patient declined follow-up amniocentesis. At birth, this newborn was documented to have normal male genitalia and a 46,XY karyotype. An additional two cases underwent amniocentesis only and were documented to have 45,X/46,XY mosaicism. High-resolution detailed ultrasound study between 16 and 22 weeks revealed seven fetuses with normal male genitalia and one fetus with ambiguous genitalia. Of the four neonates with true 45,X/46,XY mosaicism this was the only one found to have ambiguous genitalia. We conclude that the work-up of patients with 45,X/46,XY mosaicism should include ultrasound study to look for ambiguous genitalia. This allows appropriate counselling regarding the natural history of the condition and aids in the planning for management in the postnatal period.

Molecular cytogenetics: an essential component of modern prenatal diagnosis

Traditional cytogenetic studies with high-resolution banding techniques have been the mainstay of prenatal diagnosis for > 20 years. However, this approach is limited by the resolution of light microscopy, and it requires cultured cells, necessitating a significant delay in obtaining chromosome studies. The advent of molecular cytogenetics, or fluorescence in situ hybridization, has added an adjunctive tool to overcome both these limitations. During a 16-month period 35 prenatal diagnosis cases had molecular cytogenetic studies performed; 71% of the evaluations were informative. We present five of these cases to illustrate the benefits of this technique for clinical prenatal diagnosis.

Early prenatal diagnosis of an infratentorial arachnoid cyst: association with an unbalanced translocation

Arachnoid cysts are an uncommon central nervous system malformation, representing only 1 per cent of all intracranial masses. We report the second-trimester prenatal diagnosis of a posterior fossa arachnoid cyst, associated with an unbalanced X;9 translocation.

Determination of normal human fetal immunoglobulin M levels

Immunoglobulin M (IgM) levels were measured in 198 cord blood samples from 192 apparently normal pregnancies from 24 weeks of gestation to term. Simple linear regression analysis yielded a standard curve for IgM development during pregnancy showing a 0.5 mg/dl increase in IgM per week of gestation. This curve allows the comparison of fetal IgM levels from pregnancies considered to be at risk for intrauterine infection.

Osteogenesis imperfecta and campomelic dysplasia: difficulties in prenatal diagnosis

The classic features of osteogenesis imperfecta and campomelic dysplasia typically are so specific that these two forms of skeletal dysplasia are among the few that can be diagnosed in the second trimester of pregnancy. We report a series of seven examples of osteogenesis imperfecta and one example of campomelic dwarfism to illustrate the difficulty of differentiating these two disorders in utero. The prenatal sonographic findings in three of the osteogenesis imperfecta cases mimicked campomelic dwarfism, whereas the case of campomelic dwarfism was antenatally diagnosed as osteogenesis imperfecta.

Gorlin syndrome (naevoid basal cell carcinoma syndrome): prenatal detection in a fetus with macrocephaly and ventriculomegaly

The Gorlin (naevoid basal cell carcinoma) syndrome is an autosomal dominant disorder consisting principally of naevoid basal cell carcinomas, odontogenic keratocysts, skeletal abnormalities, and intracranial calcification. We report the prenatal detection of the Gorlin syndrome by ultrasonography in a fetus with macrocephaly and mild ventriculomegaly.

Desbuquois syndrome: clinical, radiographic, and morphologic characterization

To further characterize the clinical, radiographic and chondro-osseous morphologic changes in the Desbuquois syndrome, 7 patients from three sibships are described. They all had prenatal onset severe rhizomelic and mesomelic shortness with marked joint laxity and marked micrognathia. Radiographic changes were distinct, consisting of a supernumerary ossification center between the proximal phalanx of the index finger and the second metacarpal, and variable thumb changes. The femoral necks showed enlargement of the lesser trochanter with metaphyseal breaking, producing a characteristic "monkey wrench" (Swedish key) appearance. Growth plate cartilage showed dilated cisterns of rough endoplasmic reticulum in reserve zone chondrocytes. Three of the 7 cases were diagnosed prenatally by second trimester ultrasound and one case by fetoscopy. This syndrome exhibits significant phenotypic variability and must be differentiated from the Catel-Manzke syndrome which exhibits similar radiographic changes in the hands.

Antenatal diagnosis of fetal pelvic kidneys

OBJECTIVE

To review our experience with the antenatal detection and subsequent neonatal outcome of fetuses with a pelvic kidney.

METHODS

A retrospective review of 25,551 obstetric ultrasound examinations performed after 16 weeks' gestation identified 13 cases of fetal pelvic kidneys (one per 1965 examinations).

RESULTS

Three pelvic kidneys were dysplastic; the remainder appeared sonographically normal. Seven pelvic kidneys were measured; five were smaller than expected for gestational age. Associated anomalies were detected in three cases.

CONCLUSIONS

Careful second- and third-trimester ultrasound examinations can detect an absence of the kidney in the renal fossa. Evaluating the migratory path of the kidney from the pelvis to the renal fossa will frequently result in detection of an ectopic kidney.

Increased echogenicity in the fetal abdomen: use of DNA analysis to establish a diagnosis of cystic fibrosis

The sonographic finding of increased echogenicity within the fetal abdomen presents a diagnostic dilemma, with a differential diagnosis ranging from normal variation to CF. We report the diagnostic evaluation of four cases, two of which were found to be the result of CF. On the basis of this experience, we believe that persistence of an echogenic bowel pattern, especially with bowel dilation, after 20 weeks' gestation should prompt an evaluation for CF. Using DNA analysis, approximately 75% of the cases involving CF can be detected with noninvasive studies of the parents, and confirmation by amniocentesis is performed only in those cases in which both parents are carriers of known mutations.

Intraamniotic 15(s)-15-methyl prostaglandin F2 alpha and termination of middle and late second-trimester pregnancy for genetic indications: a contemporary approach

OBJECTIVE

Our purpose was to determine whether intraamniotic 15(s)-15-methyl prostaglandin F2 alpha could serve effectively and safely as a surrogate for natural prostaglandin F2 alpha when used to effect middle and late second-trimester pregnancy termination for genetic indications. Further, we sought to compare efficacy and side effects with those found when intravaginal prostaglandin E2 is used.

STUDY DESIGN

A total of 62 patients received intraamniotic 15(s)-15-methyl prostaglandin F2 alpha and urea, and intracervical laminaria. Case patients at < or = 20 weeks' gestation (n = 32) were compared with case patients at > 20 weeks (n = 30) and with a matched group (n = 64; 1:2 ratio) of control patients in whom cervical laminaria and intraamniotic urea were used with prostaglandin E2 vaginal suppositories.

RESULTS

The mean induction-to-abortion interval among the case patients (gestational age 16 to 27 weeks) was 13 hours 11 minutes; 60 of 62 (97%) were delivered within 24 hours. There was a statistically significant negative correlation between the induction-to-abortion interval and gestational age (p = 0.04). When patients at < or = 20 weeks and those at > 20 weeks were compared, few differences were noted. The mean induction-to-abortion interval for case patients at < or = 20 weeks was 13 hours 54 minutes versus 19 hours 34 minutes for control patients (p = 0.001). One of 32 (3%) case patients remained undelivered beyond 24 hours compared with 17 of 64 (27%) control patients (p < 0.01). Immediate and delayed complications were uncommon in either group.

CONCLUSION

Our study demonstrates that 15(s)-15-methyl prostaglandin F2 alpha can serve safely as a surrogate for prostaglandin F2 alpha when used in combination with urea and laminaria for termination of pregnancy. This technique appears safe for use through 27 weeks' gestation; further investigation is encouraged.

Prenatal diagnosis of cytomegalovirus (CMV) infection: a preliminary report

Eight patients were referred for prenatal diagnosis for suspected fetal cytomegalovirus infection (CMV): six for documented first-trimester infection and two for abnormal ultrasound evaluation suggestive of fetal infection. Three methods of diagnosis were employed: (1) amniotic fluid viral cultures and CMV-specific IgM in fetal serum; (2) amniotic fluid cultures and detection by polymerase chain reaction amplification of CMV-specific DNA in chorionic villi; and (3) detection of CMV-specific DNA in villus samples only. Amniotic fluid cultures detected all cases of infection, but CMV-specific IgM was not a reliable indicator of infection in any case. DNA analysis correlated well with both culture results and clinical outcome.

Congenital nephrosis: detection of index cases through maternal serum alpha-fetoprotein screening

Congenital nephrosis is an autosomal recessive disorder with an incidence of 1 in 8000 in Finland, but it is quite rare in non-Finnish populations. In families known to be at risk, prenatal detection is possible by means of maternal serum and/or amniotic fluid alpha-fetoprotein levels. We report the antenatal diagnosis of four cases of congenital nephrosis, three of which were index cases, through maternal serum alpha-fetoprotein screening. The diagnosis was confirmed at birth in two infants. Two patients elected to terminate their pregnancies, and the diagnoses were confirmed pathologically (obliteration of foot processes on electron microscopy of fetal glomeruli) in both. In cases of elevated maternal serum alpha-fetoprotein, with unexplained and marked elevations of amniotic fluid alpha-fetoprotein and normal acetylcholinesterase levels, the diagnosis of congenital nephrosis must be considered regardless of ethnic origin.

Chorionic villus sampling: the University of Maryland experience

The University of Maryland was the first program in the state to offer chorionic villus sampling (CVS). Since the program's beginning in 1984, 998 patients have been seen with successful sampling in 99.1 percent, using both transcervical and transabdominal approaches. The overall loss rate was quite low (2.3 percent), and no increased risk of birth defects was seen. These observations demonstrate that CVS provides a safe and accurate alternative to amniocentesis.

Transcervical chorionic villus sampling and amniocentesis: a comparison of reliability, culture findings, and fetal outcome

We evaluated the reliability, culture findings, and fetal outcome after transcervical chorionic villus sampling or amniocentesis in a group of 860 patients. All procedures were performed for the indication of advanced maternal age with consistent procedure and laboratory techniques. Successful procedures were completed in 97.7% (420/430) of patients in the chorionic villus sampling group, compared with 99.5% (428/430) in the amniocentesis group (p less than 0.01). Success was more frequent with only one attempt in the amniocentesis group (427/428) versus 354 of 420 in the chorionic villus sampling group (p less than 0.001). Culture failure was more common after chorionic villus sampling (p less than 0.001). Pregnancy loss rates through 28 weeks' gestation and the entire gestation were not significantly different. The prevalence of preterm delivery did not vary between groups, but birth weights of infants in the chorionic villus sampling group were significantly greater. In summary, the present investigation supports previous findings that chorionic villus sampling is a safe alternative to amniocentesis and is not associated with long-term pregnancy complications.

Diagnosis and management of prenatally detected myelomeningocele: a preliminary report

Our experience with 23 cases of fetal myelomeningocele provides preliminary information on the outcome of these infants diagnosed in utero and managed by a multidisciplinary team. The mean age of diagnosis was 23.7 weeks (range, 16 to 34 weeks). Mean gestational age at delivery was 36.9 weeks in the 14 patients who elected to continue their pregnancies. None of the 11 infants with lumbosacral or sacral lesions developed significant ventriculomegaly before term. Of the three patients diagnosed with thoracolumbar lesions, two had progression of ventriculomegaly necessitating early delivery at 32 to 34 weeks of gestation. These preliminary findings suggest that a coordinated prenatal and neonatal approach appears to result in a favorable prognosis for infants with myelomeningocele, but that neonatal complications are common, requiring careful monitoring and aggressive management.

Early diagnosis of spina bifida: the value of cranial ultrasound markers

Ultrasonography plays an integral part in the prenatal diagnosis of neural tube defects. However, experienced sonographers with careful evaluation are successful in accurately diagnosing spina bifida only 80-90% of the time. This study was conducted to evaluate the accuracy and reliability of certain cranial ultrasound markers--the "lemon sign," cerebellar abnormalities, microcephaly, and ventriculomegaly--in facilitating the diagnosis of spina bifida in patients referred for prenatal diagnosis. Open spina bifida was diagnosed in 24 of 44 fetuses found to have neural tube defects. The lemon sign and cerebellar abnormalities were identified in all 16 fetuses in whom the diagnosis of spina bifida was made between 16-24 weeks' gestation. In four of these fetuses, the lemon sign and cerebellar abnormalities were noted 1-2 weeks before the spinal defect was identified. Microcephaly was present in 69% and ventriculomegaly in 63% of the cases. In the eight cases diagnosed after 24 weeks' gestation, the lemon sign was less reliable, being noted in only 25% of the fetuses. Ventriculomegaly increased in frequency to 75% and cerebellar abnormalities and microcephaly were present in all. Our findings indicate that these cranial ultrasound markers are extremely reliable for the early diagnosis of spina bifida; their identification should alert ultrasonographers at all skill levels to the possibility of open spina bifida.

Multicystic dysplastic kidney: natural history of prenatally detected cases

To delineate the natural history of fetal multicystic dysplastic kidneys (MDKs), all cases that were prenatally detected in the Prenatal Diagnosis Center of the University of Virginia from September 1985 to 31 August 1988 were reviewed. All patients were followed through the Center with serial ultrasound evaluations at approximately 4-week intervals, and each liveborn infant was evaluated and followed by one of the authors (S.S.H.). Of the 14 cases detected, ten were detected in the second trimester, the earliest at 16.5 weeks' gestation. Of the nine fetuses with non-lethal disease, there were two cases in which the lesion remained unchanged during observation. Both had an initial diagnosis in the third trimester. In those cases diagnosed in the second trimester (7), all showed an initial increase in the size and number of cysts, followed by involutional changes either in utero (2) or in the neonatal period (3). Two infants had immediate surgical removal of the MDK, one because of respiratory compromise, and the other because of an uncertain diagnosis on renal scan. Abnormalities of the contralateral kidney were found in 7 of 14 fetuses. Five were lethal conditions. Associated non-renal abnormalities were common in bilateral MDK (80 per cent), but rare in unilateral MDK (11 per cent).

Neonatal progeroid syndrome: more than one disease?

We report on an infant with the neonatal progeroid syndrome whose clinical course and autopsy findings indicate that this may be a heterogeneous phenotype. The infant had intrauterine growth retardation, absence of subcutaneous fat, and a wizened, aged face, all apparently characteristic of the condition, but also had congenital heart defects and urinary reflux not reported in previous cases. An elevated maternal serum alpha fetoprotein was noted at 16 weeks of gestation and late-onset growth retardation appeared after 31 weeks. Autopsy findings showed normal cerebral myelination, in contrast to findings of sudanophilic leukodystrophy in the one patient with the syndrome previously examined at autopsy. These findings suggest that the neonatal progeroid syndrome may be a phenotype and have more than one cause.

The role of ultrasonography and amniocentesis in the evaluation of pregnancies at risk for neural tube defects

To assess the relative efficacy of amniocentesis versus targeted (detailed) ultrasonography, 225 patients referred because of an elevated maternal serum alpha-fetoprotein level (79.6%) or a family history of neural tube defect (20.4%) were evaluated. Ultrasonographic examination alone detected all 26 fetal abnormalities (11 cases of anencephaly, 10 cases of open spina bifida, and five other anomalies). Twenty-eight patients declined amniocentesis; all had normal pregnancy outcomes. Of the 167 patients with apparently normal fetal anatomy by sonography, seven had elevated alpha-fetoprotein levels but no acetylcholinesterase in the amniotic fluid. Six of these pregnancies resulted in normal infants; one infant had congenital nephrosis. The remaining 160 patients had normal sonograms with normal amniotic fluid alpha-fetoprotein levels and no fetal malformations at delivery. Although these results suggest that targeted ultrasonography by experienced personnel is a reasonable alternative to amniocentesis in evaluations for neural tube defects, the availability, cost-effectiveness, and diagnostic accuracy of this approach must be well documented in large prospective studies.

Bilateral renal agenesis and Mullerian anomalies in a 47,XXX fetus

Congenital absence of the kidneys (bilateral renal agenesis, BRA) is a genetically heterogeneous condition, and all modes of inheritance have been suggested as causes. The finding of a 47,XXX chromosome constitution in a fetus with BRA and developmental arrest of the mesonephric and paramesonephric systems raises the possibility that X chromosome trisomy also may cause the urogenital adysplasia sequence.

OEIS complex (cloacal exstrophy): prenatal diagnosis in the second trimester

OEIS complex (exstrophy of the cloaca) is an association of fetal malformations that includes omphalocele, exstrophy of the bladder, imperforate anus, and spinal defects. Most cases should be prenatally detectable by maternal serum alpha-fetoprotein screening, but an accurate diagnosis is essential for appropriate counselling of the family.

Fetal evaluation by percutaneous blood sampling

Percutaneous umbilical blood sampling (cordocentesis) provides direct access to the fetal circulation in the second and third trimesters of pregnancy. Seventeen patients underwent this procedure between December 1985 and December 1986 for evaluation of a variety of clinical situations, including nonlethal fetal abnormalities detected by ultrasound, equivocal results of amniocentesis, nonimmune fetal hydrops, and isoimmune disorders. Our experience confirms the efficacy of the procedure and suggests that it may become an important tool for fetal assessment and therapy.

Ontogeny of fetal liver glucose-6-phosphatase activity

A reliable and sensitive microassay for the measurement of liver glucose-6-phosphatase is described. Human fetal liver was assayed for glucose-6-phosphatase activity from 7.5 to 24 weeks of gestation and was found to have a mean activity of 2.11 nmol per min per mg of protein. This was approximately 30 per cent of the postnatal controls assayed by the same method, but there was no evidence of a change in activity during the gestational period examined. If fetal liver tissue can be reliably obtained, it may be possible to determine a deficiency of glucose-6-phosphatase in fetuses who are at risk.

Analysis of chromosomally normal spontaneous abortions after chorionic villus sampling

Analysis of patients who spontaneously aborted chromosomally normal pregnancies following chorionic villus sampling (CVS) revealed an overall loss rate of 5.4% but a rate of only 3.2% if the procedure was performed between 9 and 12 menstrual weeks. There is preliminary evidence to suggest that a small but significant risk of infection is related to CVS.

Chorionic villus sampling: experience of the first 1000 cases

Chorionic villus sampling has become widely accepted as a first-trimester alternative to amniocentesis for the prenatal detection of genetic disorders. Our experience with 1000 consecutive cases suggests that spontaneous abortion following the procedure is related to the gestational age at which it is performed, and the rate is acceptably low (3.8%) when the procedure is performed from the ninth through the eleventh menstrual week. Later complications include chorioamnionitis (0.6%) and delayed rupture of membranes and/or oligohydramnios (0.8%). A discrepancy between the villus karyotype and that of the fetus was found in 1.7% of cases and most commonly consisted of mosaicism in the villus sample for a chromosomal abnormality that was not found in fetal samples. We conclude that although chorionic villus sampling appears to be an acceptably safe and reliable procedure, further investigation is needed before this first-trimester technique is widely utilized as an alternative to amniocentesis.

Septic shock with renal failure after chorionic villus sampling

A report of septic shock and renal failure after a chorionic villus sampling is presented. Uterine evacuation, antibiotics, and vasopressor therapy were unsuccessful in reversing hypotension, coagulopathy, and anuria. The patient's condition improved only after exploratory laparotomy and removal of the uterus, ovaries, and fallopian tubes. The incidence of such serious complications must be determined.

Chorionic villus sampling

Chorionic villus sampling in the first trimester of pregnancy has the potential to become a major tool in the prenatal diagnosis and therapy of genetic disorders. Villus samples can be used for cytogenetic and biochemical studies as well as DNA analysis. However, little is known about the effects of chorionic villus sampling on a continuing pregnancy, or the long-term effects on the subsequently delivered infants. Despite these limitations, chorionic villus sampling appears to be a major breakthrough in prenatal diagnosis.

Prenatal diagnosis by chorionic villus sampling: lessons of the first 600 cases

Chorionic villus sampling (CVS) has emerged as a first trimester alternative to amniocentesis for the prenatal detection of genetic disorders. We report our experience in 600 consecutive CVS procedures to better delineate the safety, efficacy and reliability of this new method of prenatal diagnosis. Adequate samples were obtained at the initial visit in 97 per cent of the cases, and successful cultures were established in 98.7 per cent of these patients. Chromosome abnormalities were detected in 5.9 percent of those pregnancies tested because of advanced maternal age (greater than or equal to 35 years). A discrepancy between the villus karyotype and that of the fetus was found in 2.0 per cent of cases, and most commonly consisted of mosaicism in the villus sample for a chromosomal abnormality that was not found in fetal samples. The risk of spontaneous abortion following the procedure was 6.3 per cent. We conclude that chorionic villus sampling is an acceptably safe and reliable procedure, but further investigation is needed before it can become an established technique in prenatal diagnosis.

Chorion villi sampling (CVS) for prenatal diagnosis of genetic disorders: first results and future research

Chorion villi sampling (CVS) in the first trimester of pregnancy has become available recently as an alternative method to second trimester amniocentesis for prenatal diagnosis of genetic defects. Currently there are six different tissue sampling techniques being investigated in different centers around the world, but there are very few trials in ongoing pregnancies. From chorionic villi material cytogenetic and biochemical studies as well as DNA analyses can be performed. Different methods of chromosome analysis are being investigated at the University of California San Francisco and elsewhere to determine the most efficient and reliable techniques. Larger studies will be needed to establish the efficacy and the safety of the chorionic villi sampling procedure for the mother and the developing fetus. Although CVS is preferable to amniocentesis for psychological and medical reasons (earlier elective termination of a fetus with a genetic disorder), many questions remain to be answered in carefully controlled studies.

Prenatal diagnosis of fragile (X) syndrome

A fragile site (q27) of the X chromosome has been associated with X-linked mental retardation, and the prenatal diagnosis of the fragile (X) syndrome has been shown to be possible. It is suggested that both fluorodeoxyuridine and methotrexate in thymidine-deficient media be used to demonstrate the fragile (X) in cultured amniotic fluid cells. The fetus diagnosed in utero demonstrated the dolichocephaly, large ears, flattened malar area, and large testes characteristic of the fragile (X) syndrome in the newborn period.