Prediction of an abnormal karyotype in fetuses with omphalocele

Ultrasonographic characteristics, genetic features, and maternal and fetal outcomes in fetuses with omphalocele in China: a single tertiary center study

BACKGROUND

Patients with omphalocele, a midline abdominal wall defect at the umbilical cord base, have a low survival rate. However, the long-term outcomes of fetuses with prenatally diagnosed omphalocele have scarcely been studied. Therefore, we investigated the ultrasonographic features, genetic characteristics, and maternal and fetal outcomes of fetuses with omphalocele and provided a reference for the perinatal management of such cases.

METHODS

A total of 120 pregnant females with fetal omphalocele were diagnosed using prenatal ultrasonography at the Fujian Provincial Maternity and Child Health Hospital from January 2015 to March 2022. Amniotic fluid or cord blood samples were drawn at different gestational weeks for routine karyotype analysis, chromosomal microarray analysis (CMA) detection, and whole exome sequencing (WES). The maternal and fetal outcomes were followed up.

RESULTS

Among the 120 fetuses, 27 were diagnosed with isolated omphalocele and 93 with nonisolated omphalocele using prenatal ultrasonography. Cardiac anomalies were the most observed cause in 17 fetuses. Routine karyotyping and CMA were performed on 35 patients, and chromosomal abnormalities were observed in five patients, trisomy 18 in three, trisomy 13 in one, and chromosome 8-11 translocation in one patient; all were non-isolated omphalocele cases. Six nonisolated cases had normal CMA results and conventional karyotype tests, and further WES examination revealed one pathogenic variant and two suspected pathogenic variants. Of the 120 fetuses, 112 were successfully followed up. Eighty of the 112 patients requested pregnancy termination. Seven of the cases died in utero. A 72% 1-year survival rate was observed from the successful 25 live births.

CONCLUSION

The prognosis of fetuses with nonisolated omphalocele varies greatly, and individualized analysis should be performed to determine fetal retention carefully. Routine karyotyping with CMA testing should be provided for fetuses with omphalocele. WES is an option if karyotype and CMA tests are normal. If the fetal karyotype is normal and no associated abnormalities are observed, fetuses with omphalocele could have a high survival rate, and most will have a good prognosis.

Prenatally diagnosed omphaloceles: Report of 92 cases and association with Beckwith-Wiedemann syndrome

OBJECTIVE

Describe the prevalence, perinatal and long-term outcomes of Beckwith-Wiedemann syndrome (BWS) among prenatally detected omphaloceles.

METHODS

All prenatally diagnosed omphaloceles from 2010 to 2015 within a single tertiary care centre were identified. An echocardiogram and detailed fetal ultrasound were performed, and amniocentesis was offered with karyotype/microarray analysis and BWS molecular testing. Perinatal, neonatal, and long-term outcomes were retrieved for BWS cases.

RESULTS

Among 92 omphaloceles, 62 had additional anomalies. Abnormal karyotypes were identified in 23/62 (37%) non-isolated and 2/30 (7%) isolated cases. One BWS case (5%) was identified among non-isolated omphaloceles and six BWS cases (37.5%) were identified among isolated omphaloceles after exclusion of aneuploidy. Among 19 BWS cases, 21% were conceived by ART. All omphaloceles underwent primary closure. Prenatally, macrosomia and polyhydramnios were seen in 42%. Macroglossia and nephromegaly were more commonly detected postnatally. Preterm birth occurred in 10/19 (53%) cases and cesarean deliveries were performed in 7/19 (40%) cases. Overall mortality was 20% (4/19). Embryonal tumors were diagnosed in 2/16 (12.5%) children, and neurodevelopmental outcomes were normal in 9/12 (75%) survivors.

CONCLUSIONS

After excluding aneuploidy, BWS was identified in 37.5% and 5% of isolated and non-isolated omphaloceles, respectively. Omphaloceles were small-moderate size with good long-term surgical and neurodevelopmental outcomes when isolated.

Abdominal Wall Defects-Current Treatments

Gastroschisis and omphalocele reflect the two most common abdominal wall defects in newborns. First postnatal care consists of defect coverage, avoidance of fluid and heat loss, fluid administration and gastric decompression. Definitive treatment is achieved by defect reduction and abdominal wall closure. Different techniques and timings are used depending on type and size of defect, the abdominal domain and comorbidities of the child. The present review aims to provide an overview of current treatments.

Can cell-free DNA testing be used in pregnancies with isolated fetal omphalocele? Preliminary evidence from cytogenetic results of prenatal cases

Objective: To evaluate whether cell-free DNA (cfDNA) testing could replace an invasive procedure in pregnancies with isolated fetal omphalocele.Study design: This was a retrospective study of all pregnancies with sonographically detected fetal omphalocele at three tertiary referral centers between 2012 and 2016. Invasive diagnostic testing was performed for genetic investigations using conventional karyotyping or chromosomal microarray. cfDNA testing was assumed to be offered to patients with isolated fetal omphalocele for screening for common aneuploidies.Results: Invasive genetic testing was performed in a total of 107 pregnancies with a fetal omphalocele. Abnormal karyotype was found in 66% (31/47) of nonisolated omphalocele cases and in 1.7% (1/60) of isolated omphalocele cases. No pathogenic copy number variations (CNVs) were detected in 59 cases with isolated omphalocele and normal karyotype. If cfDNA screening was used in cases with isolated omphalocele, the affected fetus with trisomy 18 would be detected, and no rare chromosomal aberrations or submicroscopic pathogenic CNVs would be missed.Conclusions: cfDNA testing could be recommended for prenatal genetic evaluation in pregnancies with isolated fetal omphalocele after thorough pretest counseling.Key Message: A very low percentage of aneuploidies and rare chromosomal/subchromosomal abnormalities are found in prenatal cases of isolated omphalocele. It seems that for pregnancies with isolated omphalocele, cfDNA testing represents an alternative for patients who choose to continue the pregnancies and are reluctant to undertake invasive diagnostic testing.

Insights into embryology and development of omphalocele

Congenital abdominal wall defects are one of the most common human birth defects with an incidence of about 1 in 2000 live births. While often discussed together abdominal wall defects consist mainly of two distinct entities namely gastroschisis and omphalocele. There is no clear consensus explaining the precise embryological mechanisms leading to the development of an omphalocele. Many clinicians and embryologists have attempted to explain congenital malformation as a result of failure of progression of normal embryonic development. This review summarizes the mechanisms involved in normal and abnormal development of the ventral abdominal wall.

Predicting fetal karyotype in fetuses with omphalocele: The current role of ultrasound

OBJECTIVE

To assess the ability of ultrasound in predicting abnormal karyotype in pregnancies with prenatally diagnosed omphaloceles and to compare its test characteristics to previously published studies.

METHODS

A retrospective case-control study of omphaloceles diagnosed at one center was performed from 1995-2007. Cases were those with an abnormal karyotype and controls were those with a normal karyotype. Data collection included demographics, karyotype results, and ultrasound findings. The number and type of associated anomalies were compared between the cases and controls. The sensitivity, specificity, positive predictive value, and negative predictive value for predicting an abnormal karyotype were calculated from previously published studies.

RESULTS

Of the 73 subjects, there were 12 cases and 61 controls. The majority of women were Caucasian and primigravida. The cases were less likely to have an isolated omphalocele [1 (8.3%) vs. 27 (42.6%), OR = 0.122; 95% CI: 0.02-0.08] but were more likely to have two or more major anomalies [8 (66.7%) vs. 17 (27.9%), OR = 5.18; 95% CI: 1.19-24.04)] compared to the controls. Cardiac anomalies and only one additional major anomaly were not different between the two groups, P > 0.05. The test characteristics for this study were similar to previously published studies.

CONCLUSIONS

Isolated omphaloceles were more likely to have a normal karyotype; however fetuses with multiple anomalies were more likely to have an abnormal karyotype. Despite advances in ultrasound technology, its ability for predicting an abnormal karyotype in these fetuses has not improved.

Structural and numerical changes of chromosome X in patients with esophageal atresia

Esophageal atresia with or without tracheoesophageal fistula (EA/TEF) is a relatively common birth defect often associated with additional congenital anomalies such as vertebral, anal, cardiovascular, renal and limb defects, the so-called VACTERL association. Yet, little is known about the causal genetic factors. Rare case reports of gastrointestinal anomalies in children with triple X syndrome prompted us to survey the incidence of structural and numerical changes of chromosome X in patients with EA/TEF. All available (n=269) karyotypes of our large (321) EA/TEF patient cohort were evaluated for X-chromosome anomalies. If sufficient DNA material was available, we determined genome-wide copy number profiles with SNP array and identified subtelomeric aberrations on the difficult to profile PAR1 region using telomere-multiplex ligation-dependent probe amplification. In addition, we investigated X-chromosome inactivation (XCI) patterns and mode of inheritance of detected aberrations in selected patients. Three EA/TEF patients had an additional maternally inherited X chromosome. These three female patients had normal random XCI patterns. Two male EA/TEF patients had small inherited duplications of the XY-linked SHOX (Short stature HOmeoboX-containing) locus. Patients were small for gestational age at birth (<P5) and had additional, mostly VACTERL associated, anomalies. Triple X syndrome is rarely described in patients with EA/TEF and no duplications of the SHOX gene were reported so far in these patients. As normal patterns of XCI were seen, overexpression of X-linked genes that escape XCI, such as the SHOX gene, could be pathogenic by disturbing developmental pathways.

Outcome of fetal exomphalos diagnosed at 11-14 weeks of gestation

OBJECTIVE

To determine whether sonographic findings in cases of exomphalos detected at the 11-14-week scan can be used to guide pregnancy management.

METHODS

Retrospective study of cases of exomphalos identified from the Fetal Medicine Unit database, University College London Hospitals between January 1998 and January 2010. Pregnancy and neonatal data were ascertained from maternal and neonatal records. Fetal exomphalos was categorized into three groups: exomphalos associated with other major structural malformation(s), isolated exomphalos with increased nuchal translucency (NT) and isolated exomphalos with normal NT.

RESULTS

A total of 98 cases of exomphalos were identified, of which 45 (45.9%) were associated with other major structural malformation(s), identified antenatally. Isolated exomphalos was found with increased NT in 22 cases (22.4%) and with normal NT in 31 cases (31.6%). Of 80 (81.6%) fetuses that were karyotyped, 43 (53.8%) had a chromosomal abnormality; the most common aneuploidy was trisomy 18 (n = 31; 72.1%). Where exomphalos was associated with other major structural abnormalities, or was isolated with increased NT, the incidence of aneuploidy was high, at 78.9% and 72.2%, respectively. Cases of isolated exomphalos with normal NT were all euploid. In 21 cases (21.4%), exomphalos resolved later in pregnancy and none had apparent abnormalities at birth; isolated exomphalos persisted in only three neonates (3.1%).

CONCLUSIONS

The finding of a major structural abnormality or of increased NT in association with exomphalos in the first trimester implies a high risk of aneuploidy. Parents can be reassured that fetuses with isolated exomphalos and normal NT are likely to be euploid.

Clinical risk factors for gastroschisis and omphalocele in humans: a review of the literature

Gastroschisis and omphalocele are usually considered together since they are both congenital abdominal wall defects, and yet their anatomy, embryogenesis, and clinical presentation and problems are quite different. In addition, it appears that the risk factors for their occurrence differ. Etiologic factors contributing to the development of these defects are unknown. To investigate this we have reviewed reports of risk factors for each anomaly and report them here. We conducted a literature search using PubMed (http://www.ncbi.nlm.nih.gov/pubmed/) for risk factors implicated in the development of gastroschisis and omphalocele. The data reviewed here from clinical studies in the literature, closely parallels the data in animal studies which we reported earlier. There is little evidence for a genetic cause in the development of gastroschisis and much evidence supporting the possibility that environmental teratogens are important contributors to the development of this defect. On the other hand, in the case of omphalocele, there was little evidence for environmental factors and substantial data indicating that genetic or familial factors may play an important role.

Correlation between the presence of liver herniation and perinatal outcome in prenatally diagnosed fetal omphalocele

AIMS

To investigate the association between the presence of liver herniation and perinatal course and outcome of fetal omphalocele.

METHODS

Cases of fetal omphalocele managed at our hospital between 1990 and 2006 were retrospectively reviewed and grouped according to the location of the liver.

RESULTS

Thirty-three fetal omphalocele cases were diagnosed. The chromosomal status of 29 of 33 fetuses was determined. The rate of chromosomal abnormalities in cases with an extracorporeal liver was significantly lower (2/18) than in the intracorporeal group (6/11) (P=0.028). In chromosomally normal cases, four with extracorporeal liver resulted in early neonatal death compared to none with intracorporeal liver. Five of the 21 chromosomally normal fetuses showed an abnormal volume of amniotic fluid. All five cases had extracorporeal liver and two of them resulted in neonatal death.

CONCLUSIONS

Fetuses with an extracorporeal liver had a lower rate of chromosomal abnormalities than those in the intracorporeal liver group. However, in chromosomally normal cases, it appeared that extracorporeal livers might be associated with more life-threatening anomalies, amniotic fluid volume abnormalities, and a higher rate of mortality than in the group with an intracorporeal liver. Upon diagnosis of fetal omphalocele, a careful search for liver location should be conducted before counseling.

[Liver hernia. Prognosis and report of 11 cases]

OBJECTIVES

Exclusive hepatocele is defined as a hernia containing in majority the liver with possibly some intestinal loops. This study was undertaken to evaluate neonatal morbidity and mortality in this series of exclusive hepatoceles.

MATERIALS AND METHODS

We reviewed 11 cases of exclusive hepatoceles with delivery at the hospital Jeanne-de-Flandre in the CHRU of Lille, in France.

RESULTS

The mean gestational age of diagnosis was 14.5+/-3.4 weeks of gestation. Karyotype determination was performed in 100% of cases: it was abnormal in one case of 11. One termination of pregnancy was performed because of trisomy 13. The mean gestational age at delivery was 38+/-1.8 weeks of gestation. Cesarean deliveries were performed in nine cases. Morbidity was important with: one case of fetal growth retardation on total hepatocele, three cases of severe respiratory distress, two cases of severe digestive complications. The mean length of stay was 42.8 days. The mean length of parenteral feeding was 14.4 days. Postnatal mortality concerned one child, which died because of a severe respiratory distress due to pulmonary hypoplasia.

CONCLUSION

In this series, morbidity is thus important, making of exclusive hepatoceles a full entity among the omphaloceles. The multidisciplinary take care is more complex but conceivable.

Chromosomal Abnormalities Associated With Omphalocele

Fetuses with omphalocele have an increased risk for chromosomal abnormalities. The risk varies with maternal age, gestational age at diagnosis, association with umbilical cord cysts, complexity of associated anomalies, and the contents of omphalocele. There is considerable evidence that genetics contributes to the etiology of omphalocele. This article provides an overview of chromosomal abnormalities associated with omphalocele and a comprehensive review of associated full aneuploidy such as trisomy 18, trisomy 13, triploidy, trisomy 21, 45,X, 47,XXY, and 47,XXX, partial aneuploidy such as dup (3q), dup (11p), inv (11), dup (1q), del (1q), dup (4q), dup (5p), dup (6q), del (9p), dup (15q), dup(17q), Pallister-Killian syndrome with mosaic tetrasomy 12p and Miller-Dieker lissencephaly syndrome with deletion of 17p13.3, and uniparental disomy (UPD) such as UPD 11 and UPD 14. Omphalocele is a prominent marker for chromosomal abnormalities. Perinatal identification of omphalocele should alert chromosomal abnormalities and familial unbalanced translocations, and prompt thorough cytogenetic investigations and genetic counseling.

Characteristics and outcome of 90 cases of fetal omphalocele

OBJECTIVE

The aim of this study was to describe the outcome of a case series of fetuses with omphalocele.

METHODS

Ninety fetuses with omphalocele at the National Center for Fetal Medicine (NCFM) between January 1985 and January 2004 were followed from the time of prenatal diagnosis. Follow-up times ranged from 6 months to 17 years. Omphaloceles were subdivided into epigastric, central and hypogastric types based on their location on the abdominal wall.

RESULTS

There were 58 central and 32 epigastric omphaloceles. Abnormal karyotype was found in 40/58 (69%) of the central and in 4/32 (12.5%) of the epigastric omphaloceles. Trisomy 18 was the most frequent abnormality associated with omphalocele. Among the fetuses with normal karyotype, 89% of the central and 71% of the epigastric cases had other anomalies. 38 (66%) of the fetuses with central omphalocele were terminated and 12 (21%) died during pregnancy or after delivery. 11 (34%) of the fetuses with epigastric omphalocele were terminated and eight (25%) died during pregnancy or after delivery. Of the 90 cases followed from the time of diagnosis there were 21 (23%) survivals. Of eight survivals with central omphalocele, only two were considered healthy while six had other anomalies and/or substantially impaired development. Of 13 survivals with epigastric omphalocele, six were considered healthy and seven had other anomalies and/or substantial impairment.

CONCLUSIONS

Fetal central and epigastric omphaloceles may be different entities: central omphaloceles are more strongly associated with abnormal karyotype (69%) than are epigastric omphaloceles (12.5%). The outcome of fetuses with omphalocele is poor irrespective of the type of omphalocele, with only eight of the 90 (9%) being alive and healthy at present. The results emphasize the importance of identifying both those fetuses with a potentially good prognosis and favorable outcome and those which are likely to have a fatal outcome.

Omphalocele: clinical outcomes in cases with normal karyotypes

OBJECTIVE

This study was undertaken to examine neonatal outcomes in karyotypically normal cases of omphalocele with respect to mode of delivery, presence of associated anomalies, presence of extracorporeal liver, and method of abdominal wall closure.

STUDY DESIGN

We reviewed 36 cases of omphalocele with delivery at University of North Carolina Hospitals between 1988 and 2001. Elective terminations and pregnancies resulting in miscarriage before 20 weeks' gestation were excluded.

RESULTS

Perinatal mortality rate was 19%. Rate of composite neonatal morbidity was 25%. Associated major anomalies were present in 11 (31%) cases and were associated with increased neonatal mortality. Cesarean deliveries were performed in 21 (58%) cases and were not associated with increased primary closure rates or decreased neonatal morbidity and mortality. Extracorporeal liver was present in 27 (75%) cases and was associated with decreased rates of primary closure but did not affect neonatal outcome.

CONCLUSION

In cases of ongoing omphalocele, perinatal mortality rates are low in the absence of associated anomalies or genetic defects. Intracorporeal liver was not associated with increased rates of associated anomalies or was it associated with increased neonatal morbidity or mortality.

Evaluation of prenatal ultrasound diagnosis of fetal abdominal wall defects by 19 European registries

OBJECTIVES

To evaluate the current effectiveness of routine prenatal ultrasound screening in detecting gastroschisis and omphalocele in Europe.

DESIGN

Data were collected by 19 congenital malformation registries from 11 European countries. The registries used the same epidemiological methodology and registration system. The study period was 30 months (July 1st 1996-December 31st 1998) and the total number of monitored pregnancies was 690,123.

RESULTS

The sensitivity of antenatal ultrasound examination in detecting omphalocele was 75% (103/137). The mean gestational age at the first detection of an anomaly was 18 +/- 6.0 gestational weeks. The overall prenatal detection rate for gastroschisis was 83% (88/106) and the mean gestational age at diagnosis was 20 +/- 7.0 gestational weeks. Detection rates varied between registries from 25 to 100% for omphalocele and from 18 to 100% for gastroschisis. Of the 137 cases of omphalocele less than half of the cases were live births (n = 56; 41%). A high number of cases resulted in fetal deaths (n = 30; 22%) and termination of pregnancy (n = 51; 37%). Of the 106 cases of gastroschisis there were 62 (59%) live births, 13 (12%) ended with intrauterine fetal death and 31 (29%) had the pregnancies terminated.

CONCLUSIONS

There is significant regional variation in detection rates in Europe reflecting different policies, equipment and the operators' experience. A high proportion of abdominal wall defects is associated with concurrent malformations, syndromes or chromosomal abnormalities, stressing the need for the introduction of repeated detailed ultrasound examination as a standard procedure. There is still a relatively high rate of elective termination of pregnancies for both defects, even in isolated cases which generally have a good prognosis after surgical repair.

Risk factors in congenital abdominal wall defects (omphalocele and gastroschisi): a study in a series of 265,858 consecutive births

The aim of this study was to describe the prevalence at birth of two abdominal wall defects (AWD), omphalocela and gastroschisis and to identify possible etiologic factors. The AWD came from 265,858 consecutive births of known ouome registered in the registry of congenital malformations of Strasbourg for the period 1979 to 1998. Request information on the child, the pregnancy, the parents and the family was obtained for cases and for controls. Hundred five cases with AWD were analysed, 55.2 % were omphalocele and 44.8 % were gastroschisis. The mean prevalence rate for omphalocele was 2.18 per 10,000 and for gastroschisis 1.76 per 10,000. Associated malformations were found in 74.1 % of omphalocele compared with 53.2 % of gastroschisis; 29.3 % of fetuses with omphalocele had an abnormal karyotype, 44,8 % had a recognizable syndrome, association or an unspecified malformation pattern; 51.0 % of fetuses with gastroschisis had additional malformations that were not of chromosomal origin, but 1 case. Antenatal ultrasound examination was able to detect 39 (67.2 %) cases of omphaloceles and 27 (57.4 %) cases of gastroschisis. In 30 (51.7 %) cases of omphalocele and in 7 (14.9 %) cases of gastroschisis parents opted for termination of pregnancy. The overall survival rate was 14 (24.1 %) for omphalocele and 30 (63.8 %) for gastroschisis. Weight, length and head circumference at birth of infants with AWD were less than those of controls. The weight of placenta of infants with AWD was not different from the weight of placenta of controls. Gastroschisis was associated with significantly younger maternal age than omphalocele. Pregnancies with AWD were more often complicated by threatened abortion, oligohydramnios and polyhydramnios. Mothers of children with AWD took more often medication during pregnancy than mothers of controls.

Screening for fetal abdominal wall defects

Failure of the lateral ventral folds to close by the third month of embryonic life results in an omphalocele. Although the abdominal wall defect is easily closed, the survival rate for infants with an omphalocele remains only 79%, largely the result of coexistent anomalies and chromosomal abnormalities. Gastroschisis is a deformation caused by disruption of the right omphalomesenteric artery and a resultant full-thickness defect in the abdominal wall. As a result, small bowel and, on occasion, even large bowel herniate into the amniotic space. Despite evidence of increased bowel irritability manifested by echogenic bowel wall thickening in fetuses with gastroschisis, the survival rate of more than 95% is largely the result of the lack of other severe anomalies associated with this defect. In addition, recent evidence suggests that the improvement in survival rate is also the result of improved perinatal care. The ability of perinatal specialists to categorize the defect along with associated anomalies and improved counseling regarding neonatal outcome have measurably increased the ability of families to assess the reproductive consequences and make informed decisions. This article outlines methods to identify patients at risk for having a fetus with an abdominal wall defect along with sonographic techniques to diagnose the majority of cases. Prompt consultation with individuals skilled in evaluating such defects ensures that appropriate perinatal care is provided.

Partial duplication of 3q and distal deletion of 11q in a stillbirth with an omphalocele containing the liver, short limbs, and intrauterine growth retardation

We describe a female stillbirth with duplication of 3q21-->qter and deletion of 11q23-->qter resulting from an unbalanced segregation of a maternal t(3;11) reciprocal translocation. The proband had some of the clinical features consistent with those seen in patients with dup(3q) syndrome or distal del(11q) syndrome. Prenatal sonographic examination showed short limbs, intrauterine growth retardation, and an omphalocele containing the liver.

Chromosomal anomalies in newborns with omphalocele

Omphalocele is the most common congenital abdominal wall defect; its reported incidence is 1 in 4,000 to 5,000 live births. With large defects, the liver is a median organ and lies within the sac (extracorporeal liver [ECL]). With small defects, only bowel or stomach is found outside the abdominal cavity (intracorporeal liver [ICL]). The goal of this study was to determine whether a relationship exists between the sac contents or the timing of diagnosis and the incidence of chromosomal abnormalities or survival among fetuses and newborns with omphalocele. From 1985 to 1995, 83 cases of omphalocele were managed at the authors' institution. In 50 cases the diagnosis was made using prenatal ultrasonography. All patients underwent fetal cardiac echography and amniocentesis. Twenty-four pregnancies were terminated electively because of severe associated anomalies. Of the 59 live births, 41 patients (69%) survived. The incidences of cardiac, chromosomal, and other anomalies were 24% (14), 10% (6), and 21% (16), respectively. Omphalocele with ICL is associated with a better survival rate than omphalocele with ECL (82% v 48%; P < .01) despite the significantly higher rate of karyotype abnormalities (16% v 0%; P < .05). The prognosis was poorer for patients with prenatally diagnosed omphalocele than for those with a postnatal diagnosis (mortality rate, 42% v 21%) because the former group had a higher percentage (70% v 9%) of ECL. Although the incidence of cardiac anomalies was similar for the ECL and ICL groups (33% v 18%), the former had more complex malformations. Death usually occurred in newborns who had neonatal respiratory distress owing to prematurity, or in those with chromosomal or cardiac anomalies. Chromosomal anomalies occurred mainly in cases of small omphaloceles that contained gut only, and it was the major cause of death among this group. In ECL cases, survival was primarily affected by the associated complex cardiac anomalies.

Prenatal diagnosis of fetal abdominal wall defects: a retrospective analysis of 44 cases

Forty-four fetal abdominal wall defects, consisting of 31 omphalocoeles, 11 cases of gastroschisis, and two body stalk anomalies (which are excluded from further analysis), were diagnosed at 12-39 weeks (median 26 weeks) of gestation. In 10/31 (32 per cent) cases of omphalocoele and in 4/11 (36 per cent) cases of gastroschisis, multiple congenital anomalies were diagnosed. A normal amount of amniotic fluid was present in 39 cases; in three cases of omphalocoele an abnormal amount of amniotic fluid (polyhydramnios, n = 2; oligohydramnios, n = 1) was seen. Prenatally, intrauterine growth retardation (IUGR) was diagnosed in each type of anomaly only once, although the birth weight was below the tenth centile in 23 per cent of omphalocoeles and in 36 per cent of cases of gastroschisis. An abnormal prenatal karyotpye was established in 5/25 (20 per cent) cases of omphalocoele versus none in the gastroschisis group. In 36 cases an expectant obstetric management was followed, and in six cases of omphalocoele the pregnancies were terminated because of severe multiple anomalies (n = 3) or an abnormal prenatal karyotype (n = 3). The preterm delivery rate (excluding terminations) was 12/25 (48 per cent) in the omphalocoele subgroup versus 8/11 (73 per cent) in the gastroschisis subgroup. The Caesarean section rate was almost identical (19 versus 18 per cent) in both subgroups; the majority (n = 5) were performed to protect the abdominal wall defect. The overall survival rate was 39 per cent in the omphalocoele group; in all surviving infants this was the sole congenital anomaly and in each instance there was a normal karyotype. In the gastroschisis group, 8/11 (72 per cent) infants survived, of which two children also displayed unilateral hydronephrosis.

Genetic diagnosis from formalin-fixed fetal tissue using FISH: a new tool for genetic counseling in subsequent pregnancies

We evaluated the feasibility of retrospective genetic testing for numerical chromosomal aberrations by applying the FISH technique to formalin-fixed fetal tissue. Fetal tissue from 10 old cases with known aneuploidy and from 13 cases with known fetal malformations, were tested with specific DNA probes for pericentromeric repeat regions of chromosomes 13/21, 18, X and Y. FISH diagnosis concurred with karyotype in all nine cases with sufficient cells. Numerical aberration was diagnosed in six out of 13 cases with fetal malformations.