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.

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.

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.

Analyse génétique du fœtus à partir du sang maternel

Circulating fetal DNA in maternal plasma and serum was first demonstrated by Lo et al. in 1997 and has become a useful tool for prenatal diagnosis less than five years later. There is more and more evidence that the trophoblastic cells act as the major source of this circulating fetal DNA. Contrary to fetal cells analysis in maternal blood which requires isolation and enrichment procedures, fetal DNA analysis is relatively easy to perform with the use of real-time PCR. Non-invasive fetal sex and fetal RHD genotype determination are, to date, the two main clinical indications. Those newly offered possibilities have changed the management of pregnant women who are carriers for X-linked genetic disorders; prenatal diagnosis by choriovillous sampling could only be performed for male fetuses avoiding an unnecessary risk of fetal loss for female fetuses. Moreover, fetal RHD genotyping by maternal blood analysis could be useful in RhD-negative women at risk of immunization in order to adapt prophylactic anti-D injection.

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.

Volume contrast imaging: A new approach to identify fetal thoracic structures

OBJECTIVE

To assess the potential of volume contrast imaging for evaluation of fetal intrathoracic structures.

METHODS

Volume contrast imaging is a new ultrasonographic method that increases the contrast between tissues. It consists of a 5- to 10-mm-thick slice-shaped volume image projected on a 2-dimensional screen. The rendering process applied on the slice smoothens the speckle pattern of the image by filling up the gaps with tissue information from the adjacent layers. To evaluate the potential of volume contrast imaging for enhancing the contrast between fetal lungs and surrounding tissues, we compared the ability of volume contrast imaging and conventional ultrasonography to image the fetal thymus in 50 controls. We also applied volume contrast imaging to prenatal imaging of 6 thoracic abnormalities (2 left congenital diaphragmatic hernias, 1 right diaphragmatic hernia, 2 congenital adenomatoid lung malformations, and 1 lung sequestration).

RESULTS

In controls, the thymus was identified in all cases by volume contrast imaging and in 42 cases (84%) by conventional 2-dimensional ultrasonography. Clear images of macrocystic and microcystic congenital adenomatoid malformations were obtained by volume contrast imaging, which provided precise contouring of the lesions. In cases with congenital diaphragmatic hernias, volume contrast imaging provided clear images of the limits of the lungs ipsilateral to the hernia.

CONCLUSIONS

Volume contrast imaging may enhance the contrast between fetal lungs and surrounding organs and can be applied to prenatal imaging of intrathoracic structures in cases with thoracic fetal abnormalities.

Fetal lung volume estimated by 3-dimensional ultrasonography and magnetic resonance imaging in cases with isolated congenital diaphragmatic hernia

OBJECTIVE

To assess the agreement of 3-dimensional ultrasonography and magnetic resonance imaging in estimating fetal lung volume in cases with isolated congenital diaphragmatic hernia.

METHODS

Fetal lung volume was measured in 11 cases of congenital diaphragmatic hernia (10 left and 1 right) by 3-dimensional ultrasonography and magnetic resonance imaging. These examinations were performed during the same week. The operators were blinded to each other's results. Intraclass correlation was used to evaluate the agreement between 3-dimensional ultrasonography and magnetic resonance imaging estimations of the ipsilateral, contralateral, and total fetal lung volume. A Bland-Altman graph was plotted to detect possible discordant observations.

RESULTS

The global intraclass correlation coefficient between magnetic resonance imaging and 3-dimensional ultrasonographic measurement of fetal lung volume was 0.94 (95% confidence interval, 0.78-0.98) with no outliers observed on the Bland-Altman plot.

CONCLUSIONS

There is a good agreement between 3-dimensional ultrasonography and magnetic resonance imaging for fetal lung volume estimation in cases with congenital diaphragmatic hernia.

Prenatal sonographic diagnosis of congenital hiatal hernia

OBJECTIVES

To report a rare case of congenital hiatal hernia illustrating the importance of its prenatal diagnosis as well as to discuss the prenatal sonographic criteria.

CASE REPORT

A case of congenital hiatal hernia was diagnosed by ultrasound at 33 weeks of gestation. After a normal second-trimester morphologic ultrasound examination, a hypoechogenic mass was detected in the posterior mediastinum juxtaposed to the vertebral body and seemed to be in continuity with the intra-abdominal stomach bubble. Congenital hiatal hernia was suspected mainly because of the dynamic position of the stomach during the examination, without mediastinal shift, and normal appearance of the diaphragm on parasagittal sections of the thorax. Postnatal management was planned with no urgency and surgery was successfully performed, confirming the diagnosis.

CONCLUSION

This rare case illustrates the importance of prenatal diagnosis of congenital hiatal hernia for prenatal counseling and postnatal management. The ultrasound criterion for prenatal diagnosis is the presence of a herniated stomach in the posterior mediastinum, sometimes having a dynamic position during examination, with no mediastinal shift associated with normal diaphragm appearance on parasagittal sections of the thorax.

Antenatal manifestations of Smith-Lemli-Opitz (RSH) syndrome: A retrospective survey of 30 cases

Smith-Lemli-Opitz (SLO) syndrome or RSH syndrome is an autosomal recessive multiple malformation, and mental retardation syndrome ascribed to 7-dehydrocholesterol reductase deficiency, and usually diagnosed in the early postnatal period. Reviewing a series of 30 cases of SLO, we have investigated the variable antenatal expression of the disorder. Intrauterine growth retardation (IUGR) was the most frequent detectable trait (20/30). IUGR was either isolated (9/20) or associated with at least one other anomaly (11/20), including nuchal edema, renal, cardiac, cerebral malformations, genital anomalies, or polydactyly. In this last group, 3/11 presented with multiple malformations (> or =3 anomalies). In 5/30 cases, isolated nuchal edema (3/30), and isolated cardiac (1/30) or renal malformations (1/30) were the only detectable anomalies. Ultrasound findings were considered normal in 5/30 cases and were abnormal in 25/30 cases (83%), but early detection of multiple malformations was rare (3/30, 10%). We suggest giving consideration to a more systematic sterol analysis when dealing with IUGR, especially when associated anomalies are detected.

Can Three-Dimensional Ultrasound Be Used for the Assessment of the Fetal Lung Volume in Cases of Congenital Diaphragmatic Hernia?

We report on 2 fetuses with congenital diaphragmatic hernia (CDH) in whom the fetal lung volumes were estimated by three-dimensional ultrasound and the results compared with the postmortem lung volume measurements. Both examiners (sonographer and pathologist) were blinded to each other's results. The 1st case was a right CDH diagnosed at 20 weeks of gestation. The 2nd case was a left CDH diagnosed at 22 weeks of gestation. Both pregnancies were terminated upon request of the parents. Three-dimensional ultrasound estimation of the fetal lung volume was performed 1 day before termination of pregnancy using the technique of rotation of the three perpendicular planes. The left and right lung volumes estimated by three-dimensional ultrasound were 3.88 and 1.87 cm(3), respectively, in the 1st case and 0 and 5.52 cm(3), respectively, in the 2nd case. On postmortem examination, the left and right lung volumes were 3.0 and 2.2 cm(3), respectively, in case 1 and 1.1 and 5.6 cm(3), respectively, in case 2. This suggests that a three-dimensional estimation of pulmonary volumes may be correlated with postmortem findings in cases with CDH.

Perinatal three-dimensional color power Doppler ultrasonography of vein of Galen aneurysms

OBJECTIVE

To present the prenatal and postnatal three-dimensional color power Doppler ultrasonographic features in cases of vein of Galen aneurysmal malformation.

METHODS

Prenatal three-dimensional color power Doppler ultrasonography was used to image the neurovascular malformations in 3 fetuses with vein of Galen aneurysms and in unaffected control fetuses at the same gestational age. Postnatal transfontanel three-dimensional power Doppler ultrasonography was also performed in the third affected case and in an unaffected control neonate. The feeding and drainage vessels were analyzed in the three-dimensional rendering mode.

RESULTS

The first case was complicated by porencephaly and fetal heart failure, and the pregnancy was terminated. The other 2 cases were uncomplicated prenatally, but 1 of the infants died after aneurysmal embolization due to acute cerebral ischemia. The angioarchitecture of the arteriovenous fistula was characterized in greater detail by three-dimensional color power Doppler ultrasonography than by two-dimensional ultrasonography, especially regarding the anatomic features of the feeding and drainage vessels and their connections with the dilated vein of Galen.

CONCLUSIONS

Three-dimensional color power Doppler ultrasonography provided detailed images of the aneurysmal malformation and its vascular connections. Further studies are needed to correlate three-dimensional vascular imaging patterns with outcome.

Pericardial teratoma complicated by hydrops: successful fetal therapy by thoracoamniotic shunting

Pericardial teratoma is a potentially curable lesion that may become life threatening when it induces mediastinal compression and fetal hydrops. So far, cases with fetal hydrops have been managed by elective delivery or pericardial needle decompression. We report a case in which pericardial teratoma resulted in fetal hydrops. Following transpleural needling of the fetal pericardium at 29 weeks and 6 days, pericardial effusion decreased but hydrops persisted, while major unilateral pleural effusion appeared. A thoracoamniotic shunt was placed at 30 weeks and 5 days. Hydrops resolved, although incompletely. The baby was delivered at 32 weeks and was operated upon on day 3. This observation suggests that fetal hydrops associated with pericardial teratoma may improve following thoracoamniotic shunting. Fetal therapy may limit the risks of respiratory distress arising from the combined effect of airways compression and lung immaturity.

Kinetics of SRY gene appearance in maternal serum: detection by real time PCR in early pregnancy after assisted reproductive technique

BACKGROUND

Fetal DNA circulating in maternal serum offers a possibility for non-invasive prenatal diagnosis but its kinetics during very early pregnancy is still unclear. In order to clarify this point, the studies on the kinetics of fetal DNA appearance in maternal serum were conducted on patients undergoing assisted reproduction.

METHODS

Using a quantitative real time PCR assay, the presence of SRY gene sequences was evaluated in the serum of patients at the onset of pregnancy.

RESULTS

Twenty-seven patients were originally studied but first trimester abortion occurred in five cases. Among the 22 ongoing pregnancies, ten were found to bear at least one male fetus and all sera from these women gave positive results for SRY gene detection. The SRY gene was found to be detectable as soon as day 18 after embryo transfer in one case and it had been found in the other nine patients by day 37.

CONCLUSIONS

Fetal DNA is found in maternal serum even before the fetal circulation is established, which is highly suggestive that it is released, at least in part, from the trophoblast. Detection of fetal DNA in maternal serum very early in pregnancy may have clinical implications such as with the management of pregnant women carrying a fetus at risk for congenital adrenal hyperplasia.

Fetal DNA in maternal serum: does it persist after pregnancy?

Fetal DNA and cells present in maternal blood have previously been used for non-invasive prenatal diagnosis. However, some fetal cells can persist in maternal blood after a previous pregnancy. Fetal rhesus status and sex determination have been performed by using amplification by real-time polymerase chain reaction (PCR) of fetal DNA sequences present in maternal circulation; no false-positive results related to persistent fetal DNA from a previous pregnancy have been reported. This idea has recently been challenged. An SRY real-time PCR assay was performed on the serum of 67 pregnant women carrying a female fetus but having previously given birth to at least one boy and on the serum of 30 healthy non-pregnant women with a past male pregnancy. In all cases, serum was negative for the SRY gene. These data suggest that fetal DNA from a previous pregnancy cannot be detected in maternal serum, even by using a highly sensitive technique. Therefore, non-invasive prenatal diagnosis by fetal sex determination for women at risk of producing children with X-linked disorders, and fetal RHD genotyping is reliable and secure as previously demonstrated.

First-trimester diagnosis of osteogenesis imperfecta associated with encephalocele by conventional and three-dimensional ultrasound

To illustrate the three-dimensional sonographic features of a rare genetic disorder, we report on prenatal diagnosis of osteogenesis imperfecta congenita associated with encephalocele at 13 weeks of gestation, using conventional and three-dimensional ultrasound. Because the parents were first-degree cousins and on the basis of the family history, a recessive autosomal inheritance was suspected. Of seven previous pregnancies, five were unaffected and two had been terminated in the second trimester owing to a similar abnormality (one affected boy and one affected girl). In the case we present, the diagnosis was made on the basis of two-dimensional ultrasound performed by physicians aware of the history; the quality of three-dimensional ultrasound imaging suggests that this technique might have contributed toward establishing a precise diagnosis in the absence of a positive family history. Besides, the global view provided by three-dimensional surface-rendering images made the parents more confident of the accuracy of the diagnosis. Although osteogenesis imperfecta congenita is generally considered as autosomal dominant, the case we report suggests that it may be inherited in a recessive autosomal fashion at least when associated with encephalocele. Three-dimensional ultrasound confirmed the conventional two-dimensional examination and was helpful in convincing the parents of the accuracy of the diagnosis.

[CMV infection: when should medical termination of pregnancy be discussed?]

OBJECTIVES

To determine in which circumstances termination of pregnancy (TOP) could be proposed in case of CMV infection.

PATIENTS AND METHODS

An inquiry was conducted concerning the practice of doctors working in French foetal medicine units in case of CMV infection. The question asked was: "What is your attitude if confronted to a CMV seroconversion at 23 weeks of amenorrhoea with positive PCR at 28 WA, and normal MRI and ultrasound scan at third trimester?"

RESULTS

Thirty-five obstetricians answered. Forty-nine percent do not perform foetal blood sampling (FBS). Among them 1/17 would accept TOP. Fifty-one percent do perform FBS. In this group, 33% would accept TOP in case of negative FBS and 83% if FBS shows foetal infection.

DISCUSSION AND CONCLUSION

Techniques available for diagnosis and prognosis of foetal infections are based on PCR on amniotic fluid, ultrasound, MRI and FBS. To date correlation of those tests with foetal outcome has not been fully validated. TOP could therefore be an option in 2 circumstances: when signs of certain severe foetal disease with positive PCR and ultrasound abnormalities; on statistical arguments: if positive PCR, and normal ultrasound, the risk of handicap is approximately 10%, the severity of the handicap being impossible to predict. In this last hypothesis, it is tempting to use additional arguments such as FBS even if the interpretation of the results of this test has not been scientifically validated. Such cases with positive PCR and normal ultrasound in which inconsistent decisions are made are likely to be more frequent because of routine serologic screening policy.

[CT pelvimetry: a new approach using multi detector CT and volume rendering]

The authors describe a new technique of CT pelvimetry, using multi detector CT. This protocol is able to provide an anatomic view of the bony pelvis as well as classical measurements for pelvimetry. The acquisition is made using low technical parameters allowing the radiation dose to remain similar to that of conventional CT. Helical acquisition with thin slices and interleaved reconstruction provides adequate material for Volume Rendering reconstruction. Presets of the software may give readily available images within seconds, saving time for the radiologist. Although this technique might be performed using single slice helical CT, multi detector CT makes it faster and more accurate as the acquisition time is shorter. Final images are more easily understood by obstetricians and midwives, leading to a better understanding of dystocias. This anatomical information is obviously superior to that of conventional CT. Because it is simple to perform, has no medical time cost for the radiologist if a Volume Rendering software is available, and does not require additional radiation, we believe that this technique should replace conventional CT or conventional pelvimetry.

Management of asymptomatic neonatal cystic adenomatoid malformations

BACKGROUND/PURPOSE

Although much is known about the prenatal course of cystic adenomatoid malformations (CCAM), the postnatal course of asymptomatic lesion is less well documented. The authors studied the pre- and postnatal course and treatment of asymptomatic CCAM.

METHODS

The authors reviewed the files of all patients referred to Necker-Enfants Malades hospital with an antenatal diagnosis of CCAM and asymptomatic at birth.

RESULTS

Files of 29 patients were studied. The first x-ray film was considered normal in 12 cases (41.3%). Computed tomography was normal in 4 cases and showed cystic lung malformations in the other patients. Postnatally, clinical manifestations occurred in 3 patients (10.3%). CCAM vanished in 6 cases. Surgical resection of CCAM was performed in 17 cases (58.6%). All the patients currently are asymptomatic.

CONCLUSIONS

CCAM can shrink or vanish during pregnancy and antenatal ultrasound findings are not predictive of the postnatal course. Thus, all infants with prenatal diagnosis of CCAM require postnatal evaluation. Normal radiographic findings at birth do not rule out CCAM persistence on CT. The treatment of asymptomatic CCAM is controversial. Surgery may be advocated because of the low morbidity and the prevention of late complications, above all, cancer. The surgical indications of small (<3 cm) and asymptomatic lesions should be discussed on a case-by-case basis with the parents.

Prenatal diagnosis of spinal muscular atrophy by genetic analysis of circulating fetal cells

Spinal muscular atrophy (SMA) has a prevalence of one in 6000 births and a one in 40 heterozygote frequency. We aimed to develop a routine test for non-invasive prenatal diagnosis. We tested blood with ISET (isolation by size of epithelial tumour or trophoblastic cells) in 12 pregnant women whose babies were at risk of SMA. Using genetic analysis of fetal cells, we identified SMA in all nine isolated from the three mothers carrying an affected child. There was no mutation in any of the 26 fetal cells isolated from the nine women with an unaffected child. Our results show that non-invasive detection of genetic diseases by the analysis of maternal blood is feasible.

[First trimester fetal sex determination in maternal serum using real-time PCR]

OBJECTIVE

Fetal sex prediction can be achieved using PCR targeted at the SRY gene by analyzing cell-free fetal DNA in maternal serum. Unfortunately, the results reported to date, show lack of sensitivity, especially in the first trimester of pregnancy. Therefore, determination of fetal sex by maternal serum analysis can not replace caryotype analysis following chorionic villus sampling.

PATIENTS AND METHODS

A new highly sensitive real-time PCR was developed to detect a SRY gene sequence in maternal serum. Analysis was performed on 121 pregnant women during their first trimester of pregnancy (mean gestational age: 11.8 weeks). Among them, 61 had at least one previous male-bearing pregnancy. Results were compared to fetal sex.

RESULTS

SRY PCR analysis of maternal serum was in complete concordance with fetal sex. Among the 121 pregnant women, 61 were bearing a male fetus and 60 a female fetus No false negative results were observed. Furthermore, no false positive results results occurred although 27 women carried female fetus during the current pregnancy, had at least one previous male-bearing pregnancy.

DISCUSSION AND CONCLUSION

This study demonstrates that a reliable, non-invasive sex determination can be achieved by PCR analysis of maternal serum during the first trimester of pregnancy. This non-invasive approach for fetal sex prediction should have great implications in the management of pregnant women carriers of an X-linked genetic disorder. Prenatal diagnosis is thus performed for male fetuses only, avoiding invasive procedures and the risk of fetal loss for female fetuses.

Omphalocele: beyond the size issue

A small omphalocele was diagnosed and followed up prenatally. Ultrasonography examinations and clinical examination at birth were all consistent with an isolated, small omphalocele. Immediate surgical exploration at birth found an associated type I intestinal atresia. This rare association and the need for immediate postnatal management of omphalocele are discussed, and the literature is reviewed.

Expression of surfactant proteins and thyroid transcription factor 1 in an ovine model of congenital diaphragmatic hernia

BACKGROUND/PURPOSE

The question of delayed lung maturation in congenital diaphragmatic hernia (CDH) is pending. Data about surfactant proteins (SPs) are sparse in human fetuses and discrepant in the ovine CDH model. The purpose of this study was to investigate, in the ovine surgically created CDH model, the expression of SPs and of thyroid transcription factor 1 (TTF-1), a key regulator of lung development that also controls the expression of surfactant proteins.

METHODS

Diaphragmatic hernia (DH) was created surgically in lamb fetuses on day 85 of gestation. On day 139, 5 DH and 6 control fetuses were retrieved by cesarean section. The mRNA levels for SPs and TTF-1 were determined by Northern blot analysis; SP-A and SP-B protein levels were assessed by Western blot analysis.

RESULTS

In DH lungs, SP-A, SP-B, and SP-C messenger RNAs were diminished by 82%, 67%, and 32%, respectively, compared with control level. SP-A and SP-B protein amounts were decreased consistently. TTF-1 expression was not altered in the surgical model.

CONCLUSIONS

SP's deficiency appears to be a common feature of the various CDH models. By contrast with the nitrofen model, TTF-1 expression was not altered in the surgical model indicating different underlying molecular mechanisms in both models.

Middle cerebral artery Doppler in fetuses with transposition of the great arteries

OBJECTIVE

A previous anthropometric study has shown that neonates with transposition of the great arteries have a smaller head circumference and intracranial volume, which may be related to a lower oxygen content of blood delivered to the head and upper extremities. The aim of this study was to compare Doppler blood flow velocity waveforms in fetuses with transposition of the great arteries with those in healthy fetuses.

METHODS

Doppler blood flow velocimetry was performed in the middle cerebral artery, the umbilical artery, the aorta and the ductus venosus in a consecutive series of 23 fetuses with transposition of the great arteries between 36 and 38 weeks' gestation. The control group consisted of 40 healthy fetuses matched for gestational age.

RESULTS

There was no significant difference in pulsatility indices in the umbilical artery, the aorta and the ductus venosus between fetuses with transposition of the great arteries and controls. The median middle cerebral artery pulsatility index in the group with transposition of the great arteries was 1.37 (range, 1.10-2.02) and was significantly lower than that in the control group (median, 1.68; range, 1.46-2.04) (P < 0.001, Mann-Whitney test).

CONCLUSIONS

The lower pulsatility indices observed in the middle cerebral artery of fetuses with transposition of the great arteries may reflect a trend towards cerebral vasodilation. This phenomenon could be an indicator of hypoxemia and/or hypercapnia restricted to areas perfused by the preisthmus aorta and be related to the characteristics of the circulation in fetuses with transposition of the great arteries.

First-trimester fetal sex determination in maternal serum using real-time PCR

Fetal sex prediction can be achieved using PCR targeted at the SRY gene by analysing cell-free fetal DNA in maternal serum. Unfortunately, the results reported to date show a lack of sensitivity, especially during the first trimester of pregnancy. Therefore, determination of fetal sex by maternal serum analysis could not replace karyotype analysis following chorionic villus sampling. A new highly sensitive real-time PCR was developed to detect an SRY gene sequence in maternal serum. Analysis was performed on 121 pregnant women during the first trimester of pregnancy (mean gestational age: 11.8 weeks). Among them, 51 had at least one previous male-bearing pregnancy. Results were compared with fetal sex. SRY PCR analysis of maternal serum was in complete concordance with fetal sex. Among the 121 pregnant women, 61 were bearing a male fetus and 60 a female fetus. No false-negative results were observed. Furthermore, no false-positive results occurred, even though 27 women carrying a female fetus during the current pregnancy had at least one previous male-bearing pregnancy. This study demonstrates that a reliable, non-invasive sex determination can be achieved by PCR analysis of maternal serum during the first trimester of pregnancy. This non-invasive approach for fetal sex prediction should have great implications in the management of pregnant women who are carriers of an X-linked genetic disorder. Prenatal diagnosis might thus be performed for male fetuses only, avoiding invasive procedures and the risk of the loss of female fetuses.

Determination of the anatomical location of an antenatal intestinal occlusion by magnetic resonance imaging

Intestinal occlusion occurs in approximately 1 in 3000 births. Its diagnosis can be made in utero with ultrasound however, determination of its precise location is difficult to achieve. We report herein the feasibility of diagnosing and locating a fetal small-intestine occlusion with the use of magnetic resonance imaging.

Fetal lung volume measurement by magnetic resonance imaging in congenital diaphragmatic hernia

OBJECTIVE

To study the potential for prenatal magnetic resonance imaging to predict pulmonary hypoplasia in congenital diaphragmatic hernia.

DESIGN

Prospective observational study.

SETTING

Tertiary care centre.

PARTICIPANTS

Thirteen cases of congenital diaphragmatic hernia (11 left, 2 right) without associated anomalies and 74 controls.

METHODS

Measurements by magnetic resonance imaging of fetal lung volume were achieved. In the control fetuses, a regression analysis was performed to associate fetal lung volume with gestational age. This yielded a formula allowing calculation of the expected fetal lung volume as a function of gestational age. In the cases with congenital diaphragmatic hernia, the observed/expected fetal lung volume ratio was compared with perinatal 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 following formula: Fetal lung volume (mL) = exp (1.24722 + 0.08939 x gestational age in weeks). The observed/expected fetal lung volume ratio was significantly lower in congenital diaphragmatic hernia (median: 0.31, range: 0.06-0.63), than in controls (median: 0.99, range: 0.42-1.94). This ratio was significantly less in the infants with congenital diaphragmatic hernia who died (median: 0.26, range: 0.06-0.63) compared with those who survived (median: 0.46, range: 0.35-0.56). The observed: expected fetal lung volume ratio was significantly correlated with the post mortem lung: body weight ratio.

CONCLUSION

In isolated congenital diaphragmatic hernia, fetal lung volume measurement by magnetic resonance imaging is a potential predictor of pulmonary hypoplasia and postnatal outcome. Further studies are required to establish the clinical value of magnetic resonance imaging for the prenatal assessment of fetal lungs.

Validity of sonographic formulas for estimating fetal weight below 1,250 g: a series of 119 cases

OBJECTIVE

The aim of this study was to determine the accuracy of sonographic methods for estimating fetal weight < 1,250 g on the basis of ten published formulas falling into two principal categories: general formulas applied to all fetuses, and formulas specifically developed for very-low-weight fetuses.

METHODS

Recent biometric data (obtained less than 7 days before birth) on 119 fetuses weighing < 1,250 g were used retrospectively. Estimated fetal weights derived from ten published formulas were compared to actual weights. For each equation, the errors in predicting fetal weight were used to calculate mean percentage error and standard deviation of the mean error. The t test was used to determine whether the mean errors were significatively different from zero. The F test was used to determine if there were significant differences in the standard deviation of the mean errors.

RESULTS

The mean birth weight of infants was 956 +/- (SD) 183 g at a gestational age of 29 +/- (SD) 2.3 weeks. The best three formulas were the Hadlock, Sabbagha and Mielke which generated a mean error of -0.25, 2.81 and 0.29 not statistically different from zero with standard deviations of 13.02, 9.14 and 11.96, which were not statistically different.

CONCLUSION

In our population of very-low-birth-weight infants, the use of specific formulas targeted to those fetuses does not provide a more accurate estimation of fetal weight.

Ultrastructural evaluation of lung maturation in a sheep model of diaphragmatic hernia and tracheal occlusion

In fetuses with diaphragmatic hernia (DH) lung development is impaired, and pulmonary hypoplasia is one of the main factors responsible for the poor outcome of the disease. A possible treatment consists of occluding trachea during lung development to retain pulmonary fluid and to force the lung to expand. Although it appeared promising at first, this technique has recently been reported to decrease type II cell number and to induce surfactant deficiency. The aim of this study was to investigate lung maturation further through ultrastructural examination in a fetal lamb model of DH created at 85 d, followed or not by endoscopic balloon tracheal occlusion (TO) at 120 d of gestation. The proportion of alveolar epithelial type I and type II cells was altered by both treatments: the type I/type II cell ratio, which was about 2 in control lungs, was decreased 4.5-fold in DH lungs but was increased 4.5-fold in DH+TO lungs. The proportion of undifferentiated cells was increased in DH lungs. Indeterminate cells sharing features of type II and type I cells that were not observed in controls were seldom seen in DH lungs and were numerous in DH+TO lungs. The number of lamellar bodies per type II cell was decreased in both DH and DH+TO groups. In DH lungs, wall structure presented an immature appearance, with cellular connective tissue and poor secondary septation of saccules. In DH+TO lungs, primary septa appeared more mature, with reduced connective tissue, but secondary septa were still buds, although elastin was present at their tips. A single capillary layer was found in all three groups (control, DH, and DH+TO) with no sign of septal capillary pairing. This first investigation in DH and DH+TO lungs through transmission electron microscopy thus enabled us to show that compression and forced expansion of the lung are both responsible for alterations in type II cell differentiation and septal development.

The reasons for termination of pregnancy in the third trimester

OBJECTIVE

To analyse the process in making decisions leading to termination of pregnancy in the third trimester and to evaluate the maternal morbidity associated with this procedure.

DESIGN

Retrospective study.

SETTING

The Maternité Port Royal University Hospital, Paris, France.

POPULATION

A consecutive series of 956 terminations of pregnancy performed for fetal anomalies in singleton pregnancies, 305 of which were in the third trimester and 651 in the second.

MAIN OUTCOME MEASURES

Indications for termination of pregnancy; process leading to late termination of pregnancy; maternal morbidity.

RESULTS

One hundred and thirteen (37%) third trimester terminations of pregnancy were associated with false negative resulted from the results of earlier screening tests. In 15 terminations (5%), the decision was postponed, although the poor fetal prognosis was established earlier. In 55 (18%) the diagnosis was not possible earlier than the third trimester, and in 122 (40%) the diagnosis was possible earlier but the poor prognosis for the fetus was not established until the third trimester. Maternal morbidity due to termination of pregnancy was similar in the second and third trimester.

CONCLUSION

One-third of late terminations of pregnancy could have been avoided by more efficient screening in the second trimester. However, because fetal prognosis is not always clear when a malformation is diagnosed, postponing the decision until fetal development allows more thorough evaluation and may avoid unnecessary termination of pregnancy in the second trimester. This could be the main beneficial aspect of not setting a limit to the gestational age for performing termination of pregnancy.

Lung growth and maturation after tracheal occlusion in diaphragmatic hernia

Tracheal occlusion (TO) was performed at 120 d of gestation by noninvasive endoscopic technique using a releasable latex balloon, in fetal lambs with diaphragmatic hernia (DH) established at 85 d. The lungs were studied at 139 d in five fetuses with DH + TO, five fetuses with DH only, and six control fetuses. Fluid retention consecutive to TO allowed fetal lungs to grow. Histological pulmonary structure was more mature in DH + TO than in DH alone. The growth-inducing effect of TO was however incomplete, with an increased protein/DNA ratio. Tissue phospholipids were increased, but this was not reflected in the surfactant compartment. The major surfactant component, disaturated phosphatidylcholine, was reduced to 58% of its control value in DH, and further reduced to 17.5% of its control value in DH + TO. The proportion of surfactant protein B immunoreactive cells, assumed to represent the proportion of type II cells, was increased in DH (27% of all parenchymal cells), and reduced in DH + TO (7.8%) as compared with control fetuses (15%). In conclusion, although noninvasive tracheal occlusion in utero is feasible and may partly compensate the adverse effects of DH on lung organogenesis, it reduces the number of type II cells and induces a dramatic surfactant deficit. Using this technique in human fetuses requires careful consideration until further evaluation of lung functional characteristics has been achieved in this experimental model.

Absence of expression of RhD by human trophoblast cells

OBJECTIVE

Our purpose was to determine whether the RhD gene is expressed in trophoblast at any stage of gestation.

STUDY DESIGN

Trophoblast and fetal tissue were obtained from 18 pregnancies at 8 to 40 weeks' gestation. Deoxyribonucleic acid and ribonucleic acid were extracted from trophoblast. Complementary deoxyribonucleic acid was synthesized from ribonucleic acid, and reverse transcriptase-polymerase chain reaction was performed using primers specific for the RhD gene. Deoxyribonucleic acid was extracted from fetal tissue to determine the fetal RhD status by means of polymerase chain reaction. Antigen expression was also sought by analytic cytometric analysis (flow cytometry and immunocytochemistry) using a monoclonal anti-D antibody.

RESULTS

Trophoblast was studied from various combinations of RhD-positive and RhD-negative fetuses (on deoxyribonucleic acid) from mothers to find no RhD gene expression in any sample. Flow cytometry and immunocytochemistry confirmed this by demonstrating no RhD antigen sites on trophoblast cells.

CONCLUSION

Contrary to a previous report, we conclude that the RhD gene is not expressed in human trophoblast in any trimester.

Tracheal obstruction in experimental diaphragmatic hernia: an endoscopic approach in the fetal lamb

Congenital diaphragmatic hernia (CDH) is associated with a neonatal mortality of up to 50 per cent resulting from pulmonary hypoplasia. Experimental ligation of the trachea increases pulmonary growth in fetuses with experimental diaphragmatic hernia (EDH). To provide a potentially reversible tracheal occlusion (TO) using a minimally invasive procedure, we designed the endoscopic placement of a latex tracheal balloon in fetal lambs with EDH. Following surgical creation of a left EDH at 85 days' gestation, endoscopic occlusion of the fetal trachea was performed at 120 days. The fetuses were retrieved at 139 days. The procedure was successful in 5/11 attempts, resulting in liveborns in which the balloon occluded the trachea completely with expanded lungs and reduction of the herniated viscera into the abdomen. These cases were compared with five cases of EDH without TO and six controls. In the TO group, the lung weight was significantly greater but the radial alveolar count, DNA content, and protein content were similar to normal controls. All lung growth parameters were greater in the TO than in the EDH group. Occlusion of the trachea using an endoscopic technique could provide a useful alternative to open fetal surgery in fetuses with CDH.

Maternal position during labor: effects on fetal oxygen saturation measured by pulse oximetry

OBJECTIVE

To determine the effects of maternal left lateral, right lateral, and supine positions during labor on fetal oxygen saturation measured by pulse oximetry.

METHODS

Fetal oxygen saturation measured by pulse oximetry was obtained in 15 laboring women randomly and successively adopting left lateral, supine, and right lateral positions for 10 minutes each. Repeated measures analysis of variance was used for statistical analysis.

RESULTS

Changes in fetal oxygen saturation were observed in different maternal positions. The supine position was associated with a lower fetal oxygen saturation than the left lateral position. One supine hypotensive syndrome occurred and was associated with a drop in fetal oxygen saturation.

CONCLUSION

Maternal supine position during labor is associated with a lower fetal oxygen saturation than the left lateral position.

[Drug treatment of threatened premature labor]

The problem of the treatment of premature labor has not yet been resolved. The positive effect of using sympathomimetics is not as significant as was initially thought and they are not free of side-effects. A review of the literature forms the basis of a comparison of sympathomimetics with nifedipine and indomethacin. The latter sometimes offer a better alternative but must be used with care. The potential benefits of oxytocin antagonists are still being evaluated.

[Transvaginal colposuspension. A series of 49 cases]

Retrospective study from january 1991 to May 1993 of 49 patients undergoing transvaginal colposuspension (TVC) for urinary stress incontinence (USI).

SURGICAL TECHNIQUE

14 TVC performed using Raz's technique, including 11 with non absorbable suture material. 35 TVC were performed by longitudinal incision, including 26 with non-absorbable suture material.

RESULTS

Peroperative complications: 3 accidental bladder lesions (6.1%), 2 hemorrhages during detachment of Retzius (4%). Postoperative complications: temperature over 38 degrees in 10 cases (17%), 3 urinary tract infections (5.1%), 1 phlebitis (post sacro-spino-fixation). Functional results: 3 early failures at 2 months (93.9% good results). TVC is a simple technique for dealing with USI but longer follow-up is necessary for its invalidation.