PubMed Health⌕ Search

Biomedical subjects

A Benachi

Publications and source records attributed to A Benachi.

35 records · Page 2Linked to original sources

[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.

DNA↗

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.

Blood Flow Velocity↗

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.

DNA↗

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.

Case-Control Studies↗

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.

Abortion, Induced↗

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.

Airway Obstruction↗

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.

DNA↗

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.

Animals↗

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.

Airway Obstruction↗

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.

Adult↗

[Transvaginal colposuspension. A series of 49 cases].

UNLABELLED: 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.

Adult↗

[Genetic analysis of the fetus using maternal blood].

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.

DNA↗

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.

Female↗

[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.

Female↗