Clinical course and outcome of antenatally detected atrioventricular block: experience of a single tertiary centre and review of the literature

OBJECTIVE

The objective is to study the course and outcome of fetuses with congenital atrioventricular block (AVB) in a single centre.

METHODS

Retrospective analysis of cases diagnosed prenatally with second and third degree AVB. The clinical characteristics and outcome of fetal AVB were evaluated including in utero treatment.

RESULTS

Sixty-two cases were studied. AVB was associated with a congenital heart defect (CHD-AVB) in 17 cases (27%), whereas it was isolated (i-AVB) in 45 (73%), 42 of which were associated with maternal antibodies. There were nine (52.9%) live births in the CHD-AVB group, five of which (55%) resulted in infant deaths. In the i-AVB group, there were 40/45 (88.9%) live births and 1/40 (2.5%) infant death; 36 (90%) babies required a permanent pacemaker. The only factor predictive of postnatal death was the presence of CHD (5/9 vs 1/39 or 48.7 [3.6; 1457.7], p < 0.001). Nineteen fetuses (40.5%) with i-AVB received steroids in utero. No difference in outcome was found between the AVB treated in utero versus the no-treatment group in terms of permanent pacemaker placement, postnatal death or development of dilated cardiomyopathy.

CONCLUSION

The most important prognostic factor for congenital AVB is the association with CHD. In utero treatment remains questionable.

Three-dimensional helical computed tomography in prenatal diagnosis of fetal skeletal dysplasia

OBJECTIVES

(1) To study the use and diagnostic value, as a complement to ultrasound, of helical computed tomography (helical CT) to differentiate normal fetuses from cases of skeletal dysplasia; (2) to define the most relevant indications for helical CT; and (3) to evaluate its diagnostic performance with respect to radiological criteria considered discriminatory.

METHODS

This was a retrospective study from 2005 to 2008 in 67 pregnant women who underwent helical CT after 26 weeks of gestation for suspected fetal skeletal dysplasia due to fetal shortened long bones on ultrasound (≤ 10(th) percentile), either alone or associated with other bone abnormalities. The results were compared with pediatric examinations in 41 cases and with fetal autopsy findings after elective termination of pregnancy in the others.

RESULTS

Helical CT had a sensitivity of 82%, specificity of 91% and positive and negative predictive values of 90% and 83%, respectively, for diagnosis of fetal skeletal dysplasia. An etiological diagnosis that had not been suspected at ultrasound was specified in 15% of cases and diagnoses suspected at ultrasound were confirmed in 24% and discounted in 43% of cases. The prevalence of skeletal dysplasia was increased in cases of micromelia < 3(rd) percentile or if there was a combination of bone signs. Helical CT showed 69% sensitivity in identifying individual predefined pathological bone signs which were confirmed on fetal autopsy findings.

CONCLUSION

Helical CT is a key examination, in combination with ultrasound, in the diagnosis of fetal skeletal dysplasia from 26 weeks of gestation. It should be reserved for cases with severe micromelia below the 3(rd) percentile and for those with micromelia ≤ 10(th) percentile associated with another bone sign. A checklist of discriminatory signs is proposed.

Hidden mortality of prenatally diagnosed vein of Galen aneurysmal malformation: retrospective study and review of the literature

OBJECTIVE

To evaluate the prognosis of prenatally diagnosed vein of Galen aneurysmal malformation (VGAM) in a large cohort with this condition and to review the literature on prenatally diagnosed VGAM.

METHODS

This was a retrospective study of all cases of prenatally diagnosed VGAM managed in our referral center during a 12-year period. VGAM was categorized as being either isolated or associated with any other abnormality, based on fetal ultrasound and magnetic resonance imaging findings. Poor outcomes comprised termination of pregnancy with confirmation of antenatal findings, perinatal death and severe cardiac and/or neurological impairment in survivors. The literature was also reviewed for similar cases.

RESULTS

Twenty-one cases of prenatally diagnosed VGAM were managed in our center. Four (19.0%) cases were isolated and 17 (81.0%) were associated with other anomalies. There were nine terminations (42.9%) and six neonatal deaths (28.6%). Six children (28.6%) were still alive at last follow-up, of whom three had abnormal neurological development. VGAM associated with other anomalies was strongly associated with a poor outcome compared with isolated forms (P < 0.0001). One hundred and nine cases from the literature were also reviewed.

CONCLUSION

Fetuses with prenatally diagnosed VGAM have unexpectedly poor outcomes in the presence of cardiac or cerebral anomalies, while those with strictly isolated VGAM tend to have more favorable outcomes. Our literature review corroborates these findings.

Is complex gastroschisis predictable by prenatal ultrasound?

OBJECTIVE

To establish a correlation between prenatal ultrasound findings and postnatal outcome in neonates with gastroschisis (GS).

DESIGN

Retrospective case-control study.

SETTING

Prenatal ultrasound reports, labour and neonatal intensive care unit notes, and paediatric surgical clinic records were reviewed.

POPULATION

Neonates with an antenatal diagnosis of isolated GS.

METHODS

The neonates were divided into two groups: one with associated bowel complications including intestinal atresia, perforation, necrosis or volvulus ('complex' GS), and the second without bowel complication ('simple' GS). Prenatal ultrasound markers: small-for-gestational-age, intra-abdominal and extra-abdominal bowel dilatation (>6 mm), thickened intestinal wall and stomach dilatation were correlated with outcome.

MAIN OUTCOME MEASURES

Fetal or neonatal death in complex versus simple GS. Time on parenteral nutrition and duration of hospital stay were also noted.

RESULTS

In all, 105 cases were eligible for analysis. Survival rate was 101/105 (96.2%). None of the ultrasound markers was predictive of fetal or neonatal death. Fourteen of 103 live-born babies (14.6%) had complex GS, which was associated with longer time on parenteral nutrition [8.0 (51.5-390) versus 33.5 (25.3-53.3) days, P<0.001] and longer duration of hospital stay [85.3 (55.5-210) versus 41.5 (33.0-64.8) days, P<0.001]. Infants with complex GS were more likely to require bowel resection and stoma placement (P<0.05). Intra-abdominal bowel dilatation was the only predictive ultrasound marker of complex GS (odds ratio 4.13, 95% CI 1.32-12.90; P=0.018). Receiver operating characteristic curve for observed/expected bowel diameter yielded 6 as the cutoff value for predicting complex GS (odds ratio 7.9, 95% CI 2.3-27.3; P=0.001) with 54% and 88% for sensibility and specificity, respectively.

CONCLUSIONS

Intra-abdominal bowel dilatation is the only ultrasound marker predictive of complex GS but it is a strong marker.

Factors associated with partial and complete regression of fetal lung lesions

OBJECTIVE

A decrease in the volume of congenital pulmonary malformations (CPM) can be observed on prenatal ultrasonography, but the underlying mechanism for this phenomenon is unknown. Our objective was to identify factors associated with the prenatal reduction in size of cystic and/or hyperechoic lung lesions.

METHODS

This was a retrospective study of cases with a prenatal diagnosis of hyperechoic and/or cystic lung lesion. The extent of reduction in lesion size was calculated from ultrasound measurements. Clinical, ultrasound, radiological and histological data were tested for their relationship with prenatal CPM reduction.

RESULTS

In a 4-year period, 36 patients were referred with a cystic and/or hyperechoic fetal lung lesion diagnosed at a mean gestational age of 23.4 weeks. The lesions were cystic in 16 cases (44%), hyperechoic in 12 (33%) and both in eight (22%). The malformation was no longer visible before birth (apparent disappearance) in nine cases (25%), shrank by 18-90% in 15 (42%) and did not reduce in 12 (33%). Findings on postnatal computed tomography were always abnormal. Isolated hyperechoic lesions were significantly more likely to shrink in utero. The mean reductions were 79%, 35% and 19%, for isolated hyperechoic, cystic and mixed lesions, respectively (P=0.001). Only 8% of hyperechoic lesions demonstrated no volume reduction, as compared to 50% and 42% of cystic and mixed lesions, respectively (P=0.03). Greater gestational age at birth was also associated with a decrease in the incidence of malformations (P=0.02). In cases that underwent surgery, hyperechoic lesions were linked to a variety of pathological diagnoses, whereas cystic lesions were all described histologically as congenital cystic adenomatoid malformations.

CONCLUSIONS

Prenatal size reduction of fetal lung malformations is associated with isolated hyperechogenicity and greater gestational age at birth. This might result from the resumption of normal lung development after local disruption of lung growth.

Keyhole sign: how specific is it for the diagnosis of posterior urethral valves?

OBJECTIVES

Posterior urethral valves (PUV) are the most common cause of renal impairment in boys during early childhood. Although antenatal suspicion of this pathology has become quite common in recent years, prenatal diagnosis remains challenging. The aim of this study was to evaluate the predictive value of different ultrasound criteria currently used to diagnose PUV.

METHODS

We reviewed the antenatal and postnatal files of 54 male patients referred to our center from 2000 to 2006 after detection of fetal bilateral hydronephrosis. The following ultrasound criteria were evaluated in relation to the postnatal diagnosis of PUV: amniotic fluid volume, bladder wall thickness, bladder dilatation and the presence of the 'keyhole sign'.

RESULTS

Forty-two fetuses (77.8%) were suspected to have PUV on prenatal examination. Out of these, 29 (69.0%) had PUV confirmed postnatally. The sensitivity and specificity of the antenatal diagnosis of PUV were 94% and 43%, respectively. Increased bladder wall thickness and bladder dilatation were highly associated with the diagnosis of PUV (P < 0.001). However, a thick-walled bladder was observed in 39.1% and a dilated bladder in 47.8% of the infants with a postnatal diagnosis other than PUV. The presence of the keyhole sign was not found to predict a diagnosis of PUV (P = 0.27).

CONCLUSION

In this series the use of classical prenatal ultrasound signs to diagnose PUV showed high sensitivity but low specificity. The best diagnostic indicators were increased bladder wall thickness and dilatation of the bladder. The keyhole sign was not found to be a reliable predictor of PUV.

Prenatal diagnosis of cardiac rhabdomyomas: incidence of associated cerebral lesions of tuberous sclerosis complex

OBJECTIVES

To determine the prevalence of specific cerebral lesions of tuberous sclerosis complex (TSC) and neurological outcome in cases diagnosed prenatally with cardiac rhabdomyomas.

METHODS

We reviewed all fetuses diagnosed prenatally with cardiac rhabdomyomas which had undergone detailed ultrasound evaluation and cerebral magnetic resonance imaging (MRI) and which were recorded in the database of a single institution covering the period January 1992 to December 2005.

RESULTS

Fifty-one fetuses were included in the study. MRI was performed at a mean +/- SD gestational age of 30 +/- 3 gestational weeks and showed specific lesions of TSC in 49% of cases. Termination of pregnancy was chosen by the parents in 26 cases. Neurological development was studied in 20 cases, follow-up lasting 4.8 +/- 2.9 years. Neurodevelopmental events occurred during the follow-up period in 45% of cases. Neurological complications occurred in 67% of patients who had cerebral lesions at MRI and in 33% of patients with normal MRI results. There was no significant difference between the two groups of patients (P = 0.2).

CONCLUSION

In fetuses with cardiac rhabdomyomas detailed ultrasound examination and third-trimester cerebral MRI are able to diagnose most TSC cerebral lesions, but fail to determine neurological outcome.

[MRI and fetal multidetector CT in the diagnosis of fetal malformations]

Prenatal imaging has benefitted from rapid technological progress in the last ten years. Ultrasound remains the standard screening method for fetal malformations but can be hindered by the bony structure of the skull. In particular, it can be difficult to distinguish between white and grey matter. MRI is a useful complementary method for detecting brain malformations. In particular, MRI is necessary to detect associated malformations and to obtain a precise diagnosis when ultrasound examination shows ventricular dilation. MRI is taking an increasingly important place in the assessment and prognostication of extracranial malformations such as congenital diaphagmatic hernia. We reviewed 2885 fetal MRI examinations. Fetal computed tomography is gradually replacing plain maternal abdominal radiography. We examined 90 CT films for fetal bone malformations.

Three-dimensional sonographic measurement of contralateral lung volume in fetuses with isolated congenital diaphragmatic hernia

PURPOSE

To use 3-dimensional sonography (3DUS) to measure contralateral lung volume and evaluate the potential of this measurement to predict neonatal outcome in isolated congenital diaphragmatic hernia (CDH).

METHODS

Between January 2002 and December 2004, the contralateral lung volumes of 39 fetuses with isolated CDH were measured via 3DUS using rotational multiplanar imaging. The observed/expected contralateral fetal lung volume ratios (o/e-ContFLVR) were compared with the lung/head ratio (LHR), observed/expected total fetal lung volume ratio (o/e-TotFLVR), and postnatal outcome.

RESULTS

Contralateral lung volumes are less reduced than total lung volumes in CDH. The bias and precision of 3DUS in estimating contralateral lung volumes were 0.99 cm(3) and 1.11 cm(3), respectively, with absolute limits of agreement ranging from -1.19 cm(3) to +3.17 cm(3). The o/e-ContFLVR was significantly lower in neonatal death cases (median, 0.49 cm(3); range, 0.22-0.99 cm(3)) than in survival cases (median, 0.58 cm(3); range, 0.42-0.92 cm(3) [p < 0.01]). Overall accuracy of the o/e-ContFLVR, o/e-TotFLVR, and LHR in predicting neonatal death were 67.7% (21/31), 80.7% (25/31), and 77.4% (24/31), respectively.

CONCLUSION

Although o/e-ContFLVR can be precisely measured with 3DUS and can be used to predict neonatal death in CDH, it is less accurate than LHR and o/e-TotFLVR for that purpose.

Predicting perinatal outcome in isolated congenital diaphragmatic hernia using fetal pulmonary artery diameters

OBJECTIVE

The aim of the study was to evaluate the potential of fetal pulmonary artery (PA) diameters to predict perinatal death and pulmonary arterial hypertension (PAH) in congenital diaphragmatic hernia (CDH).

STUDY DESIGN

In this prospective observational study, observed PA (main, right, and left) diameters were measured at the level of the 3 vessels in 21 fetuses with isolated CDH and in 85 controls at 22 to 36 weeks. The observed/expected (o/e) diameters of the main, contralateral, and ipsilateral PAs were calculated by comparing these measurements with reference values obtained in our previous study and correlated with perinatal death and postnatal PAH.

RESULTS

The o/e PA diameters were significantly reduced in fetuses with CDH compared to controls (P < .001) and in fetuses with CDH who died (P < .050). However, there was no significant association between PA diameters and PAH (P >or= .050).

CONCLUSIONS

The PA diameters might be useful to predict perinatal death in isolated CDH but not postnatal PAH, suggesting that PA diameters are probably related to the severity of pulmonary hypoplasia.

Pleiotropic effects of CEP290 (NPHP6) mutations extend to Meckel syndrome

Meckel syndrome (MKS) is a rare autosomal recessive lethal condition characterized by central nervous system malformations, polydactyly, multicystic kidney dysplasia, and ductal changes of the liver. Three loci have been mapped (MKS1-MKS3), and two genes have been identified (MKS1/FLJ20345 and MKS3/TMEM67), whereas the gene at the MKS2 locus remains unknown. To identify new MKS loci, a genomewide linkage scan was performed using 10-cM-resolution microsatellite markers in eight families. The highest heterogeneity LOD score was obtained for chromosome 12, in an interval containing CEP290, a gene recently identified as causative of Joubert syndrome (JS) and isolated Leber congenital amaurosis. In view of our recent findings of allelism, at the MKS3 locus, between these two disorders, CEP290 was considered a candidate, and homozygous or compound heterozygous truncating mutations were identified in four families. Sequencing of additional cases identified CEP290 mutations in two fetuses with MKS and in four families presenting a cerebro-reno-digital syndrome, with a phenotype overlapping MKS and JS, further demonstrating that MKS and JS can be variable expressions of the same ciliopathy. These data identify a fourth locus for MKS (MKS4) and the CEP290 gene as responsible for MKS.

Stability of the m.8993T->G mtDNA mutation load during human embryofetal development has implications for the feasibility of prenatal diagnosis in NARP syndrome

BACKGROUND

Mitochondrial DNA (mtDNA) mutations cause a wide range of serious genetic diseases with maternal inheritance. Because of the high transmission risk and the absence of therapy in these disorders, at-risk couples often ask for prenatal diagnosis (PND). However, because heteroplasmy load (coexistence of mutant and wild-type mtDNA) may vary among tissues and with time, the possibility that a single fetal sample may not reflect the whole neonate impedes prenatal diagnosis of mtDNA diseases.

METHODS

We performed 13 prenatal diagnoses for the NARP (neurogenic weakness, ataxia, retinitis pigmentosa) m.8993T-->G mtDNA mutation (p.Leu156Arg) in the ATP synthase subunit 6 gene. Analyses were performed on chorionic villous (CVS) and/or amniocyte samples carried out at various stages of pregnancy, using a method enabling quantification of low DNA amounts.

RESULTS

Maternal mutant loads ranged from 0 to 75% in blood and had no predictive value for the fetus status, except for women with no detectable mutant DNA, whose fetuses were consistently mutation-free. In 8/13 PND, mutant load was <30%. These children are healthy at 2-7 years of age. In 5/13 PND, mutant load ranged from 65 to 100%, and parents preferred to terminate the pregnancies (15-22 weeks of gestation). Single-cell analysis of 20 trophoblastic cells and 21 amniocytes isolated from two affected fetuses found an average mutant load close to the overall CVS and amniocyte mutant load, despite striking intercellular variation. The m.8993T-->G mutant loads, assessed in 7, 17, 11, and 5 different tissues from 4 terminations, respectively, were identical in all tissues from a given individual (mean (SD) 78 (1.2)%, 91 (0.7)%, 74 (2)%, and 63 (1.6)% for the 4 fetuses, respectively).

CONCLUSIONS

Our results indicate that the placental/amniotic mutant loads do reflect the NARP mutant mtDNA load in the whole fetus, even when the sample amount is small, and suggest that heteroplasmy level remains stable during pregnancy, at least after 10 weeks of gestation. Although these data establish the feasibility of PND for this mutation, assessing more precisely the correlation between mutant load and disease severity should further help in interpreting PND results.

Quantitative analysis of fetal pulmonary vasculature by 3-dimensional power Doppler ultrasonography in isolated congenital diaphragmatic hernia

OBJECTIVE

The purpose of this study was to evaluate the potential of 3-dimensional (3D) power Doppler imaging to predict neonatal outcome and pulmonary arterial hypertension (PAH) in congenital diaphragmatic hernia (CDH).

STUDY DESIGN

In this prospective observational study, 3D-power Doppler ultrasonography was performed in 21 cases with isolated CDH between 23 and 33 weeks of gestation and in 58 controls between 20 and 40 weeks. Using the same preestablished settings for all cases, power Doppler was applied to each lung, and fetal lung volumes (FLV) were estimated using the rotational technique. The 3D power Doppler histogram was used to determine the vascular indices, which were plotted against gestational age and compared with neonatal outcome, PAH, gestational age, and FLV.

RESULTS

Fetal pulmonary vascular indices showed a constant distribution throughout gestation, being significantly lower in cases with CDH than in controls (P < .001). Among CDH cases, the vascular indices were significantly lower in fetuses who died (P < .05), and in fetuses with neonatal PAH (P < .05). The severity of neonatal PAH was also associated with a progressive reduction in prenatal vascular indices (P < .05). All vascular indices correlated with o/e-FLV, but not with gestational age.

CONCLUSION

All vascular indices seem to be constant throughout gestation. In isolated CDH, perinatal outcome and postnatal PAH can be predicted using the vascular indices assessed by 3D power Doppler histogram.

Syndrome d’Ehlers-Danlos vasculaire

The vascular type of Ehlers-Danlos syndrome (EDS) is a rare genetic disease transmitted as an autosomal dominant trait. It is distinguished from other forms of EDS by its unstable acrogeric morphotype and by vascular, gastrointestinal, and obstetrical complications. Diagnosis is based on various clinical signs, noninvasive imaging, and on the identification of a mutation of the COL3A1 gene, which provides diagnostic certainty but has a sensitivity of only 61%. When two major diagnostic criteria are present, a genetic test should be proposed, performed and its result presented in a multidisciplinary group. The precautionary principle requires that preventive measures be implemented when the diagnosis is suspected. All artery puncture, surgery, and gastrointestinal and uterine endoscopy are contraindicated, permissible only in life-threatening emergencies. Straining against a closed glottis and all other situations or drugs likely to raise blood pressure must be avoided. Contraception must be discussed to avoid pregnancy during the diagnostic period. Arterial lesions suggestive of the disease include dissecting aneurysms of the internal carotid and iliac arteries and of the anterior visceral branches of the abdominal aorta, fusiform aneurysms of the splenic artery, and early onset nontraumatic direct carotid-cavernous fistulae. Early-onset varicose veins, spontaneous peritonitis or unusually important perineal lesions after giving birth should also attract the physician's attention. Psychological treatment and support of patients and their families is essential, to help them both to live with their disease and to deal with the information and screening issues. The prognosis of Ehlers-Danlos syndrome, vascular type, is grim but there is wide interindividual variability and life expectancy is best among patients receiving regular follow-up. Management by an experienced multidisciplinary team, implementation of drastic prevention measures and, depending on the results of the BBEST study, the possible prescription of beta-blockers should help to reduce the risk of complications and justify hope for a real improvement in prognosis in the near future.

Predicting pulmonary hypoplasia using the sonographic fetal lung volume to body weight ratio--how precise and accurate is it?

OBJECTIVES

To determine the precision and accuracy of ultrasound in estimating the fetal lung to body weight ratio (FLB ratio) using two-dimensional (2D) and three-dimensional (3D) ultrasound by comparison with postmortem measurements, and to evaluate its potential to diagnose pulmonary hypoplasia.

METHODS

Lung volumes were estimated by 3D ultrasound (rotational technique) and fetal weights were measured by 2D ultrasound (Hadlock equation) in 35 fetuses immediately before termination of pregnancy at 15-38 weeks. Sonographic estimates of FLB ratio were compared with postmortem values. Based on the pathological definition of pulmonary hypoplasia, the accuracy of sonographic estimation of the FLB ratio was analyzed.

RESULTS

The mean gestational age at termination of pregnancy was 26.7 (range, 15-38) weeks. The mean FLB ratios were 0.018 (SD, 0.006) on ultrasound and 0.019 (SD, 0.007) at autopsy (P = 0.730). Bias and precision of sonographic FLB ratio were - 0.001 and 0.003 (absolute limits, - 0.007 to + 0.006), respectively. Pulmonary hypoplasia was diagnosed in 12 (34.3%) cases at autopsy. The sonographic FLB ratio was significantly lower in fetuses with pulmonary hypoplasia at autopsy (median, 0.011; range, 0.004-0.014) than it was in those without pulmonary hypoplasia (median, 0.022; range, 0.013-0.045, P < 0.001). The sensitivity and specificity of the sonographic FLB ratio for diagnosing pulmonary hypoplasia were 91.7% (11/12) and 91.3% (21/23), respectively, the positive and negative predictive values were 84.6% (11/13) and 95.5% (21/22), and the accuracy was 91.4% (32/35).

CONCLUSION

FLB ratio can be estimated precisely on ultrasound examination, albeit with wide limits of agreement. The sonographically estimated FLB ratio may be useful in the prediction and diagnosis of pulmonary hypoplasia.

Drainage thoraco-amniotique en urgence en cas d’épanchement pleural compressif responsable d’anasarque fœtale

OBJECTIVES

To study perinatal outcome following thoraco-amniotic shunting for fetal pleural effusions with hydrops.

MATERIALS AND METHODS

Retrospective study (1984-2004) to evaluate a policy of emergency thracoamniotic shunting in hydropic fetuses with suspected chylothorax, on the basis of the rationale that mediastinal compression could lead to acute fetal distress.

RESULTS

Shunting was performed immediately following diagnosis, and was successful in all 60 cases attempted. There were 7 pregnancy terminations, 10 in utero deaths, and 43 live births, of which 7 children died in the neonatal period and 36 survived (33 without sequels). Among the liveborn, 26 were delivered preterm (72%), of which 7 (19%) had preterm premature rupture of membranes and 4 (11%) had chorioamnionitis. Perinatal death (24/60, 40%) was related to underlying anomalies (7 cases), pulmonary hypoplasia (5 cases), chorioamnionitis (2 cases), or treatment failure for unknown reasons (10 cases). All 36 survivors had chylothorax, 33 of which were primary, and 3 were secondary to right congenital diaphragmatic hernia, pulmonary sequestration, or Noonan syndrome.

CONCLUSION

Following shunting, pleural effusion with hydrops has survival rate >50%, but still have a high rate of morbidity and mortality.

Prenatally diagnosed sacrococcygeal teratoma: a prognostic classification

PURPOSE

The objective of this study is to describe a prognostic classification for prenatally diagnosed sacrococcygeal teratoma (SCT).

METHODS

Charts from 44 fetuses were reviewed. Three groups were defined as follows: group A--tumor diameter less than 10 cm, absent or mild vascularity and slow growth; group B--diameter 10 cm or greater, pronounced vascularity or high-output cardiac failure and fast growth; group C--diameter 10 cm or greater, predominantly cystic lesion with absent or mild vascularity and slow growth.

RESULTS

Size at diagnosis, growth rate, and vascularity were higher in group B. Gestational age at delivery was lower in group B. Eleven of 21 died in the perinatal period in group B and none in groups A and C. In group C, drainage or shunting of the SCT has been performed in 6 of 10 cases.

CONCLUSIONS

Group A is associated to good maternal and perinatal outcome, as well as group C, although shunting or drainage of the SCT could be necessary. Large fast-growing SCT with rich vascularity is associated with a higher perinatal mortality and morbidity than smaller lesions with mild vascularity.

Rendering in fetal cardiac scanning: the intracardiac septa and the coronal atrioventricular valve planes

OBJECTIVE

In this study we aimed to apply spatio-temporal image correlation (STIC) rendering to visualize the virtual planes of the interventricular and interatrial septa (IVS, IAS) as well as the atrioventricular (AV) annuli plane just distal to the semilunar valves (coronal atrioventricular (CAV) plane) in normal and pathological fetal hearts, to ascertain whether these planes add to fetal cardiac examination.

METHODS

Unselected gravidae presenting for anatomy scan or patients referred for fetal echocardiography in the second and third trimesters of pregnancy with suspected or diagnosed cardiac malformation were scanned using the five planes technique with the STIC modality to obtain cardiac volume sets for each patient. Rendering capabilities were employed to obtain the 'virtual planes' to evaluate the IVS, IAS, AV annuli, and size and alignment of the great vessels.

RESULTS

A total of 136 normal scans were performed to establish a learning curve for STIC acquisition and post-processing rendering and analysis. An additional 35 cases with cardiac anomalies were accrued. In 131/136 (96.3%) normal scans the IAS and IVS were visualized successfully, while in 127/136 (93.4%) normal fetuses the CAV plane was successfully visualized. In 13 anomalous cases the IVS plane improved ventricular septal defect (VSD) evaluation, and in four the IAS plane contributed to foramen ovale evaluation. The modality improved visualization of the septa and the assessment of the defects, as well as the foramen ovale flap and pattern of movement of the foramen ovale. In five cases the CAV plane improved evaluation of the alignment of the major vessels in relation to the AV annuli, and in three the evaluation of the semilunar valves, with or without malalignment of the great vessels.

CONCLUSIONS

Rendering STIC technology allows the visualization of virtual planes (IAS, IVS, AV annuli-CAV plane), which can clarify our understanding of anatomical defects and may improve communication with the management team and family.

Renal tubular dysgenesis, a not uncommon autosomal recessive disorder leading to oligohydramnios: Role of the Renin-Angiotensin system

Renal tubular dysgenesis is a clinical disorder that is observed in fetuses and characterized by the absence or poor development of proximal tubules, early onset and persistent oligohydramnios that leads to the Potter sequence, and skull ossification defects. It may be acquired during fetal development or inherited as an autosomal recessive disease. It was shown recently that autosomal recessive renal tubular dysgenesis is genetically heterogeneous and linked to mutations in the genes that encode components of the renin-angiotensin system. This study analyzed the clinical expression of the disease in 29 fetus/neonates from 18 unrelated families and evaluated changes in renal morphology and expression of the renin-angiotensin system. The disease was uniformly severe, with perinatal death in all cases as a result of persistent anuria and hypoxia related to pulmonary hypoplasia. Severe defects in proximal tubules were observed in all fetuses from 18 gestational weeks onward, and lesions also involved other tubular segments. They were associated with thickening of the renal arterial vasculature, from the arcuate to the afferent arteries. Renal renin expression was strikingly increased in 19 of 24 patients studied, from 13 families, whereas no renal renin was detected in four patients from three families. Angiotensinogen and angiotensin-converting enzyme were absent or present in only small amounts in the proximal tubule, in correlation with the severity of tubular abnormalities. No specific changes were detected in angiotensin II receptor expression. The severity and the early onset of the clinical and pathologic expression of the disease underline the major importance of this system in fetal kidney function and development in humans. The identification of the disease on the basis of precise histologic analysis and the research of the genetic defect now allow genetic counseling and early prenatal diagnosis.

A nomogram of fetal lung volumes estimated by 3-dimensional ultrasonography using the rotational technique (virtual organ computer-aided analysis)

OBJECTIVE

The purpose of this study was to build a nomogram of normal fetal lung volumes throughout gestational age estimated by 3-dimensional ultrasonography using the rotational technique (Virtual Organ Computer-Aided Analysis [VOCAL]; GE Healthcare, Kretztechnik, Zipf, Austria).

METHODS

Fetal lung volume was assessed in 146 healthy fetuses by 3-dimensional ultrasonography using the technique of rotation of the multiplanar imaging (VOCAL). Inclusion criteria were healthy women with singleton normal pregnancies, normal fetal morphologic ultrasonographic findings, reliable dating established by dates and by ultrasonographic measurement of the crown-lump length in the first trimester, and gestational age from 20 to 37 weeks. Exclusion criteria were discordance between clinical and ultrasonographic dating, patients lost to follow-up, and birth weight disorders. Each patient was scanned once during pregnancy.

RESULTS

The right, left, and total mean pulmonary volumes ranged, respectively, from 5.37, 4.66, and 9.95 cm3 at 20 weeks to 46.06, 37.34, and 84.35 cm3 at 37 weeks. The logistic transformation analysis yielded the following formulas: right lung volume = exp(4.07/[1 + exp(21.90 - gestational age/5.44)]); left lung volume = exp(3.82/(1 + exp[22.03 - gestational age/5.17)]); and, total lung volume = exp(4.72/[1 + exp(20.30 - gestational age/6.05)]).

CONCLUSIONS

A new nomogram of fetal lung (right, left, and total) volumes throughout gestational age using the rotational technique (VOCAL) is described, and reference values have been generated.

Prenatal diagnosis of myopathy, encephalopathy, lactic acidosis, and stroke-like syndrome: contribution to understanding mitochondrial DNA segregation during human embryofetal development

INTRODUCTION

Myopathy, encephalopathy, lactic acidosis, and stroke-like (MELAS) syndrome, a maternally inherited disorder that is among the most common mitochondrial DNA (mtDNA) diseases, is usually associated with the m.3242A>G mutation of the mitochondrial tRNA(leu) gene. Very few data are available with respect to prenatal diagnosis of this serious disease. The rate of mutant versus wild-type mtDNA (heteroplasmy) in fetal DNA is indeed considered to be a poor indicator of postnatal outcome.

MATERIALS AND METHODS

Taking advantage of a novel semi-quantitative polymerase chain reaction test for m.3243A>G mutant load assessment, we carried out nine prenatal diagnoses in five unrelated women, using two different fetal tissues (chorionic villi v amniocytes) sampled at two or three different stages of pregnancy.

RESULTS

Two of the five women, although not carrying m.3243A>G in blood or extra-blood tissues, were, however, considered at risk for transmission of the mutation, as they were closely related to MELAS-affected individuals. The absence of 3243A>G in the blood of first degree relatives was associated with no mutated mtDNA in the cardiovascular system (CVS) or amniocytes, and their three children are healthy, with a follow-up of 3 months-3 years. Among the six fetuses from the three carrier women, three were shown to be homoplasmic (0% mutant load), the remaining three being heteroplasmic, with a mutant load ranging from 23% to 63%. The fetal mutant load was fairly stable at two or three different stages of pregnancy in CVS and amniocytes. Although pregnancy was terminated in the case of the fetus with a 63% mutant load, all other children are healthy with a follow-up of 3 months-6 years.

CONCLUSION

These data suggest that a prenatal diagnosis for MELAS syndrome might be helpful for at-risk families.

Genetic characterisation of circulating fetal cells allows non-invasive prenatal diagnosis of cystic fibrosis

OBJECTIVES

Cystic fibrosis (CF) is an autosomal recessive disease due to mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The purpose of this study was to develop a molecular method to characterise both paternal and maternal CFTR alleles in DNA from circulating fetal cells (CFCs) isolated by ISET (isolation by size of epithelial tumour/trophoblastic cells).

METHODS

The molecular protocol was defined by developing the F508del mutation analysis and addressing it both to single trophoblastic cells, isolated by ISET and identified by short tandem repeats (STR) genotyping, and to pooled trophoblastic genomes, thus avoiding the risk of allele drop out (ADO). This protocol was validated in 100 leucocytes from F508del carriers and subsequently blindly applied to the blood (5 mL) of 12 pregnant women, at 11 to 13 weeks of gestation, whose offspring had a 1/4 risk of CF. Ten couples were carriers of F508del mutation, while two were carriers of unknown CFTR mutations.

RESULTS

Results showed that one fetus was affected, seven were heterozygous carriers of a CFTR mutation, and four were healthy homozygotes. These findings were consistent with those obtained by chorionic villus sampling (CVS).

CONCLUSION

Our data show that the ISET-CF approach affords reliable prenatal diagnosis (PND) of cystic fibrosis and is potentially applicable to pregnant women at risk of having an affected child, thus avoiding the risk of iatrogenic miscarriage.

Prenatal diagnosis of some metabolic diseases using early amniotic fluid samples: report of a 15 years, experience

BACKGROUND

In the present study, we report the results of 132 prenatal diagnoses performed on chorionic villi and cell-free amniotic fluid obtained simultaneously at 12-13 weeks of gestation. In addition, we report the result of 59 prenatal diagnoses performed at 12-13th week using amniotic fluid only.

METHODS AND RESULTS

A total of one fetal loss (1/191) was observed when a sample of amniotic fluid was obtained at around 12-13 weeks, whereas three losses (3/82) were observed after midtrimester amniocentesis. We attribute this finding to the fact that only a very small volume of amniotic fluid was sampled using a very small needle.

CONCLUSION

From these data it appears that when a couple is facing a high risk of recurrence of some metabolic diseases, the study of chorionic villus and amniotic fluid sampled simultaneously offers a safe and reliable method of early prenatal diagnosis.

Accuracy of fetal lung volume assessed by three-dimensional sonography

OBJECTIVE

To determine the accuracy and precision of prenatal three-dimensional (3D) ultrasound in estimating fetal lung volume using the rotational multiplanar technique (VOCAL) by comparing it to postmortem volume measurements.

METHODS

Fetal lung volume was measured during 3D ultrasound examination using a rotational multiplanar technique in eight cases of congenital diaphragmatic hernia (CDH) (six left and two right-sided) and in 25 controls without pulmonary malformation, immediately before termination. Prenatal 3D sonographic estimates of fetal lung volume were compared with postmortem measurement of fetal lung volume achieved by water displacement.

RESULTS

The intraclass correlation coefficient of fetal lung volume estimated by 3D ultrasound and measured at postmortem examination was 0.95 in CDH cases and 0.99 in controls. Based on Bland-Altman analysis, the bias, precision and limits of agreement were, respectively, 0.35 cm(3), 1.46 cm(3) and between -2.51 and + 3.21 cm(3) in cases with CDH and 0.08 cm(3), 2.80 cm(3) and between -5.41 and + 5.57 cm(3) in controls. The mean relative error of 3D ultrasound fetal lung volume measurement was -7.19% (from -42.70% to + 18.11%) in CDH cases and -0.72% (from -30.25% to + 19.22%) in controls, while the mean absolute error of 3D ultrasound fetal lung volume measurement was 1.40 (range, 0.71-2.52) cm(3) and 2.12 (range, 0.05-4.98) cm(3), respectively. Accuracy of 3D ultrasound for measuring fetal lung volumes was 84.86 (range, 57.30-99.48)% in cases with CDH and 91.38 (range, 69.75-99.45)% in controls. The mean intraobserver variability for lung volume estimated by 3D ultrasound was 0.28 cm(3) in controls and 0.17 cm(3) in CDH cases.

CONCLUSION

Prenatal 3D ultrasound can estimate accurately fetal lung volume using the rotational multiplanar technique for volume measurements (VOCAL), even in fetuses with very small lungs, such as cases with isolated CDH.

Phenotypic spectrum of CHARGE syndrome in fetuses with CHD7 truncating mutations correlates with expression during human development

BACKGROUND

The acronym CHARGE refers to a non-random cluster of malformations including coloboma, heart malformation, choanal atresia, retardation of growth and/or development, genital anomalies, and ear anomalies. This set of multiple congenital anomalies is frequent, despite rare patients with normal intelligence, and prognosis remains poor. Recently, CHD7 gene mutations have been identified in CHARGE patients; however, the function of CHD7 during development remains unknown.

METHODS

We studied a series of 10 antenatal cases in whom the diagnosis of CHARGE syndrome was suspected, considering that a careful pathological description would shed light on the CHD7 function during development. CHD7 sequence analysis and in situ hybridisation were employed.

RESULTS

The diagnosis of CHARGE syndrome was confirmed in all 10 fetuses by the identification of a CHD7 heterozygous truncating mutation. Interestingly, arhinencephaly and semi-circular canal agenesis were two constant features which are not included in formal diagnostic criteria so far. In situ hybridisation analysis of the CHD7 gene during early human development emphasised the role of CHD7 in the development of the central nervous system, internal ear, and neural crest of pharyngeal arches, and more generally showed a good correlation between specific CHD7 expression pattern and the developmental anomalies observed in CHARGE syndrome.

CONCLUSIONS

These results allowed us to further refine the phenotypic spectrum of developmental anomalies resulting from CHD7 dysfunction.

Correlation between ultrasound and anatomical findings in fetuses with lower urinary tract obstruction in the first half of pregnancy

OBJECTIVE

The prognosis of fetal lower urinary tract obstruction (LUTO) depends upon renal function and also upon the underlying etiology. Precise identification of the latter remains a challenge antenatally. Our objective was to examine the underlying pathology in male fetuses with sonographic evidence of severe and isolated LUTO.

METHODS

Detailed postmortem examination was carried out after termination of pregnancy in 24 male fetuses presenting before 25 weeks of gestation with ultrasound evidence of isolated severe LUTO.

RESULTS

All fetuses had megacystis and hyperechogenic kidneys. There was anhydramnios/oligohydramnios and pelvicalyceal dilatation in 20 and 15 cases, respectively. Posterior urethral valves (PUV) were suspected antenatally in 20 cases and urethral atresia was not suspected antenatally. However, postmortem examination of the urethra demonstrated atresia in six cases, severe stenosis in eight cases, PUV in nine cases and an apparently normal urethra in one case. Renal dysplasia was found in all cases but one. Urethral atresia was the most common urethral anomaly at 12-17 weeks. Hydronephrosis was more frequent in cases with PUV (8/9) and urethral stenosis (6/8) than with urethral atresia (0/6). In LUTO presenting in the first and second trimester, hyperechogenic kidneys were predictive of renal dysplasia in 95% of cases. The association of a sagittal diameter of the bladder of at least 40 mm with hydronephrosis before 28 weeks was predictive of PUV with a positive (PPV) and negative (NPV) predictive value of 44.4% and 66.6%, respectively. Absence of hydronephrosis and a sagittal diameter of the bladder of less than 40 mm were predictive of urethral atresia or stenosis with a PPV and NPV of 100% and 47.6%, respectively. The absence of hydronephrosis was predictive of urethral atresia with a PPV and NPV of 66.6% and 100%, respectively.

CONCLUSION

LUTO in a male fetus presenting with megacystis in the first or second trimester of pregnancy is as likely to reflect urethral atresia or stenosis as it is PUV. The size of the bladder and the presence of hydronephrosis should be considered in order to improve prenatal diagnosis and counseling.

Prenatal diagnosis of pulmonary sequestration using three-dimensional power Doppler ultrasound

OBJECTIVE

To investigate the contribution of three-dimensional power Doppler ultrasound to the prenatal diagnosis of pulmonary sequestration.

METHODS

Prenatal three-dimensional power Doppler ultrasound was used to screen for an abnormal pulmonary blood supply in eight fetuses with hyperechogenic lung lesions and to image the pulmonary blood supply in 50 normal controls. A comparison was made with postnatal findings.

RESULTS

Postnatally the eight pulmonary lesions were found to be an isolated pulmonary sequestration (n = 3), a microcystic congenital adenomatoid malformation (n = 4), and a mixed (macrocystic and microcystic) congenital adenomatoid malformation (n = 1). Prenatal three-dimensional power Doppler ultrasound demonstrated an abnormal blood supply in all cases of pulmonary sequestration and in none of the other cases. Among the three cases that turned out to be pulmonary sequestrations, conventional two-dimensional ultrasound failed to identify the feeding vessel in one case and identified it at a later stage of gestation than did three-dimensional power Doppler in the other two.

CONCLUSION

Prenatal three-dimensional power Doppler ultrasound may be useful in identifying the feeding vessel and thus establishing the diagnosis of pulmonary sequestration in the presence of a hyperechogenic pulmonary lesion, allowing its differentiation from congenital cystic adenomatoid malformation.

Prenatal diagnosis of megacystis-microcolon-intestinal hypoperistalsis syndrome: contribution of amniotic fluid digestive enzyme assay and fetal urinalysis

OBJECTIVES

Megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS) is a usually lethal disease during the first year of life. There is no specific ultrasound prenatal diagnosis and no identified genetic locus. The value of amniotic fluid digestive enzyme assay and fetal urine biochemistry in the prediction of MMIHS was analysed.

METHODS

Retrospective study of 14 MMIHS cases. Amniotic fluid digestive enzymes and fetal urine biochemistry were compared in MMIHS and megabladder (63 and 264 cases respectively).

RESULTS

Abnormal amniotic fluid digestive enzyme profile (vomiting of bile or digestive secretion leakage) was observed in 8/10 MMIHS cases. These profiles were observed in 7/63 controls; 80% sensitivity (95%CI = 55%-100%); 89% specificity (95%CI = 81%-96%). Fetal urinalysis was normal in 12/12 MMIHS cases except high calcium (>0.6 mmol/l). This profile was observed in 33/264 megabladder control cases; 100% sensitivity; 98.7% specificity (95%CI = 83.5%-91.5%).

CONCLUSION

For the first time, we propose a prenatal diagnosis of MMIHS based on amniotic fluid digestive enzyme assay and on fetal urinalysis.

Thoracoamniotic shunting for fetal pleural effusions with hydrops

OBJECTIVE

The purpose of this study was to evaluate perinatal outcome after thoracoamniotic shunting for fetal pleural effusions with hydrops.

STUDY DESIGN

This was a retrospective study.

RESULTS

Shunting was performed immediately after diagnosis and was successful in all 54 of the cases that were attempted. There were 7 pregnancy terminations, 9 in utero deaths, and 38 live births, of which 7 children died in the neonatal period and 31 children survived. Among the liveborn infants, 27 infants were delivered preterm (71%), of whom 7 infants (15%) had preterm premature rupture of membranes and 4 infants (8.5%) had chorioamnionitis. Perinatal death (23/54 infants; 43%) was related to underlying anomalies (7 cases), pulmonary hypoplasia (5 cases), chorioamnionitis (2 cases), or treatment failure for unknown reasons (9 cases). All 31 survivors had chylothorax; for 28 of the survivors, the chylothorax was primary, and for 3 survivors, the chylothorax was the result of right congenital diaphragmatic hernia, pulmonary sequestration, or Noonan syndrome.

CONCLUSION

After the shunting, pleural effusion with hydrops has a 57% survival rate; premature delivery is the leading source of morbidity.

Sonography in prenatal diagnosis of congenital adrenal hyperplasia

Congenital adrenal hyperplasia (CAH) is an autosomal recessive disorder with an incidence of 1/15 000. More than 90% of CAH cases result from mutations of CYP21, leading to 21-hydroxylase deficiency. In its classical form, CAH is severe and consists of the virilizing (increase of androgens) and salt-wasting (lack of aldosterone) phenotype. When a proband exists, early prenatal diagnosis for CAH can be performed by direct molecular analysis in the first trimester. We describe herein two cases suggesting that the prenatal diagnosis of CAH can be initiated by the sonographic appearance of the adrenal gland at the second-trimester scan in the absence of a family history.

Second- and Third-Trimester Therapeutic Terminations of Pregnancy in Cases with Complete Placenta previa – Does Feticide Decrease Postdelivery Maternal Hemorrhage?

OBJECTIVE

To study the feasibility of second- and third-trimester termination of pregnancy (TOP) with complete placenta previa, and the impact of performing feticide before labor induction on maternal hemorrhagic morbidity.

PATIENTS AND METHODS

From 1987 to 2002, the databases of two referral hospitals were reviewed. We identified 15 cases of second- or third-trimester TOP in women with complete placenta previa. Feticide was performed 2-14 days before induction in 6/15 cases. Cervical ripening was achieved in 8 cases by mifepristone alone (n = 2) or by mifepristone and dilapan (n = 6). Labor was induced by vaginal gemeprost (n = 2), intramuscular (n = 5) or intravenous (n = 4) sulprostone, vaginal misoprostol (n = 1) or a combination of misoprostol and sulprostone (n = 3). Hemorrhage was defined by the need for transfusion. The difference between the preoperative and the lowest per- or postoperative maternal hemoglobin level was also analyzed.

RESULTS

Of the 9 women who underwent labor induction without previous feticide, 4 required blood transfusions, 1 of whom had a hemostat hysterectomy. The mean hemoglobin difference was 2.5 g/dl (range: 0.5-5.3). None of the 6 patients with preinduction feticide required transfusion. The hemoglobin difference was significantly smaller in this group than in terminations without previous feticide (mean: 1.0 g/dl ; range: 0.1-2.2; p = 0.03).

CONCLUSION

In cases with complete placenta previa, second- or third-trimester TOP is feasible. It carries a substantial risk of hemorrhage that might be decreased by preinduction feticide.

Fetal home monitoring for the prenatal management of gastroschisis

BACKGROUND

Fetal distress is a frequent complication of gastroschisis, and could be screened for by home monitoring, as many pregnant women expecting an affected child live far away from a specialized perinatal center. This study was undertaken to audit a policy of fetal home monitoring (FHM) to achieve early detection of fetal heart rate (FHR) abnormalities in gastroschisis.

METHODS

Daily FHM was started at a median age of 30 weeks in 31 pregnant women referred following prenatal diagnosis of isolated gastroschisis. Monitoring was considered abnormal in cases with decelerations, tachycardia, bradycardia, decreased baseline variability or absence of accelerations. When an ominous FHR was detected and confirmed by in-hospital monitoring, an emergency cesarean section (C-section) was indicated. Otherwise, an elective C-section was planned.

RESULTS

In 20 cases FHM remained normal. There were 16 elective C-sections, two emergency C-sections for FHR abnormalities detected by in-hospital monitoring, and two spontaneous premature vaginal deliveries. In 11 cases, an abnormal FHM was detected. There was one intrauterine death with acute ischemic necrosis of the large bowel. The other abnormalities consisted of decreased baseline variability with tachycardia (n = 7) or without tachycardia (n = 3) and were confirmed by in-hospital follow-up in nine cases, leading to emergency C-section.

CONCLUSION

The high rate of abnormal FHR patterns picked up by FHM in gastroschisis led to a rate of emergency C-sections of 9/31. However, this strategy failed to prevent one intrauterine death due to acute bowel necrosis.

Sensitivity and Specificity of Prenatal Features of Physiological Shunts to Predict Neonatal Clinical Status in Transposition of the Great Arteries

BACKGROUND

Although prenatal diagnosis of transposition of the great arteries (TGA) reduces neonatal mortality, the preoperative course can be complicated in infants with a restrictive foramen ovale (FO) or a ductus arteriosus (DA) constriction. We sought to determine the specificity and sensitivity of prenatal features of physiological shunts in predicting postnatal clinical status in prenatally diagnosed TGA in babies delivered in a tertiary care center providing all facilities for neonatal urgent care.

METHODS AND RESULTS

The outcomes of 130 fetuses with TGA were reviewed over a period of 5.5 years. Restriction of the FO and/or constriction of the DA could be analyzed in 119/130 fetuses at 36+/-2.7 weeks of gestation. Twenty-four out of 119 had at least 1 abnormal shunt (23 FO, 5 DA, and 4 both). Thirteen of 130 neonates had profound hypoxemia (PaO2<25 mm Hg) and metabolic acidosis (pH <7.15) in the first 30 minutes and required immediate balloon atrioseptostomy. Two who had abnormal FO and DA died despite aggressive resuscitation. The specificity and sensitivity of the fetal echo in predicting neonatal emergency were 84% and 54%, respectively. The specificity and sensitivity of a combination of restrictive FO and DA constriction were 100% and 31%, respectively.

CONCLUSIONS

Restriction of the FO and/or of the DA has a high specificity to predict the need for emergency neonatal care in fetuses with TGA, but the sensitivity is too low to detect all high-risk fetuses. Exceptional procedures should be considered for fetuses that have a combination of restrictive FO and DA constriction.

A novel PCR approach for prenatal detection of the common NEMO rearrangement in incontinentia pigmenti

OBJECTIVES

Incontinentia pigmenti (IP) is a rare X-linked dominant genodermatosis that is usually lethal in males in the prenatal period. Largely 80% of cases are accounted for by a large-scale deletion encompassing exons 4 to 10 of the NEMO gene. The aim of this work was to facilitate prenatal diagnosis of IP by devising a novel test for detection of the prevalent NEMO deletion.

METHODS

We devised a sensitive and reproducible multiplex PCR test enabling simultaneous amplification of the deleted and wild-type NEMO genes in IP female individuals.

RESULTS

Combination of this DNA test, with Xq28 linkage analysis and X-inactivation pattern study enabled us to offer an IP prenatal diagnosis in 15 of the 16 couples at a 50% risk to have an affected offspring.

CONCLUSION

A current approach to IP prenatal diagnosis is proposed on the basis of the previously mentioned molecular tools.

Syndrome d’insuffisance rénale fœtale

Some anomalies of the kidney and urinary tract evolving in utero may compromise the renal function in the newborn. Early therapeutic options do exist, especially in obstructive nephropathies. The decision depends on a correct evaluation of the foetal enal function and prognosis, which is based on a range of methods: ultrasound echography, biochemical analysis of foetal urine, and, more recently, foetal serum markers such a beta-2 micro globulin. These methods are reviewed.

Fetal serumß2-microglobulin and cystatin C in the prediction of post-natal renal function in bilateral hypoplasia and hyperechogenic enlarged kidneys

OBJECTIVES

To evaluate fetal serum ss2-microglobulin and cystatin C in the prediction of post-natal renal function in bilateral hypoplasia and hyperechogenic enlarged kidneys. Predicting post-natal renal function is crucial to the prenatal evaluation of fetal nephropathies. Prenatal ultrasound can identify terminal renal failure, but is not sensitive enough to identify infants whose post-natal renal function will be impaired. Fetal serum ss2-microglobulin and cystatin C are potential predictors of post-natal renal function.

METHODS

Fifty-four prenatally diagnosed cases of bilateral nephropathy were retrospectively reviewed. Final diagnosis was established using histological or post-natal findings: renal hypoplasia (n = 7), cystic dysplasia (n = 9), autosomal dominant polycystic kidney disease (ADPKD; n = 8) or autosomal recessive polycystic kidney disease (ARPKD; n = 22) and transient sonographic abnormalities (n = 8). Fetal serum ss2-microglobulin and cystatin C were assayed respectively in 54 and 38 cases. The prognostic value of these markers was assessed in terms of the post-natal outcome.

RESULTS

In bilateral kidney hypoplasia and cystic dysplasia, ss2-microglobulin and cystatin C were significantly (p < 0.0001 and p < 0.02 respectively) higher than in the normal control group. In hyperechogenic fetal kidneys (ARPKD, ADPKD and transient sonographic abnormalities), these markers were not different from controls. However, whereas normal values cannot exclude renal failure, abnormal values predict post-natal renal failure.

CONCLUSIONS

In bilateral renal hypoplasia and dysplasia, fetal serum ss2-microglobulin and cystatin C are good markers for post-natal renal function. However, in bilateral renal hyperechogenic enlargement, abnormal values are associated with poor post-natal renal function, but normal values cannot preclude renal failure.

Three-dimensional ultrasonographic assessment of fetal lung volume as prognostic factor in isolated congenital diaphragmatic hernia

OBJECTIVE

To evaluate the potential of three-dimensional ultrasound to predict outcome in congenital diaphragmatic hernia.

DESIGN

Prospective observational study.

SETTING

Tertiary care centre.

POPULATION

Twelve cases of isolated congenital diaphragmatic hernia (11 left-sided, 1 right-sided) and 109 controls.

METHODS

Fetal lung volume was assessed by three-dimensional ultrasound using the technique of rotation of the multiplanar imaging. In the control fetuses, a logistic transformation was performed to correlate fetal lung volume with gestational age, and the confidence interval was obtained with a bootstrap resampling. A mathematical equation was then obtained allowing calculation of the expected fetal lung volume as a function of gestational age. In fetuses with congenital diaphragmatic hernia, the observed/expected lung volume ratio was compared with postnatal outcome.

MAIN OUTCOME MEASURES

Neonatal mortality and pulmonary hypoplasia, which was defined as lung/body weight ratios less than 0.012.

RESULTS

The expected fetal lung volume was derived from the mathematical equation: Fetal lung volume (mL) = exp (4.72/(1 + exp ((20.32 - gestational age in weeks)/6.05))). The observed/expected fetal lung volume ratio was significantly lower in the congenital diaphragmatic hernia group (median: 0.34, range: 0.16-0.66), than in the control group (median: 1.02, range: 0.62-1.97, P < 0.0001). The distribution of this ratio was significantly downshifted in the infants with congenital diaphragmatic hernia who died (median: 0.19, range: 0.18-0.66) compared with survivors (median: 0.44, range: 0.36-0.66, P= 0.04). The observed/expected fetal lung volume ratio was also correlated with the postmortem lung/body weight ratio.

CONCLUSION

In isolated congenital diaphragmatic hernia, fetal lung volume measurement by three-dimensional ultrasound is a potential predictor for pulmonary hypoplasia and postnatal outcome.