[Performance and indications of noninvasive prenatal testing using cell free circulating fetal DNA (cffDNA) for the detection of fetal trisomy 21, 18 and 13 in France]. / Performance et indication du dépistage des trisomies 21, 18 et 13 en France par l'analyse de l'ADN fœtal dans le sang maternel.

OBJECTIVES: To evaluate de performances of noninvasive prenatal testing using cell free circulating fetal DNA (cffDNA) for the detection of fetal trisomy 21, 18 and 13 in a French population. MATERIALS AND METHODS: cffDNA analysis was performed by massive parallel sequencing during a multicenter, non interventional, prospective study and the results were compared with a standard fetal karyotype. RESULTS: Results were available for 886 patients who have been classified as high- or moderate-risk depending on the presence of fetal abnormalities on ultrasound examination. For the high-risk group (n=376), the sensitivity and specificity of the test were 100% and 99.9% for trisomy 21, 88% and 99.9% for trisomy 18 and 100% and 99.9% for trisomy 13. The rate of other pathogenic chromosomal abnormalities with a negative NIPT was 7.9%. In the low-risk group (n=510), the sensitivity was 100% and the specificity 99.8% for trisomy 21, and only 0.4% of pathogenic chromosomal abnormalities were revealed by fetal karyotyping but not detected by cffDNA analysis. CONCLUSION: Noninvasive prenatal testing using cffDNA for high risk patients without fetal anomalies at ultrasound could be recommended in France after counseling on the possible risk of undiagnosed anomalies.

[Down syndrome maternal serum screening: results' comments recommended by accredited biologists]. / Dépistage de la trisomie 21 par les marqueurs sériques maternels : justification des commentaires appliqués par les biologistes.

Down syndrome maternal serum screening is largely used in France. The aim of this article is to specify and to explain the different comments applied on the reports in order to optimize the management of the patient. These comments represent the consensus of the study group of the biologist accredited for Down syndrome maternal serum screening.

[Chorionic villus sampling training method]. / Technique d'apprentissage de la biopsie de trophoblaste.

OBJECTIVES: Chorionic villus sampling (CVS) in the first trimester of pregnancy has become a major tool in prenatal diagnosis. To increase the safety of CVS during training period, we have built a "BT-Trainer". MATERIALS AND METHODS: A medical device has been developed which simulates the in vivo procedure with the various layers to cross. The stratum of the layer and the accessibility of the placenta can modulate the level difficulty. CONCLUSION: Traditional strategies for clinical teaching are often insufficient and trainees may fail to achieve competence in even basic procedural skills. We present herein an easy and reproducible model of "BT-Trainer" which allows a safe and repeatable training. Efficacy of this model is currently under evaluation in a teaching program. This trainer could help gynaecologists in order to learn gradually and safely the technique and to enhance their skills and coordination.

[Impact of fetal urinary ascites on serum beta2 microglobuline in obstructive uropathies: a case report]. / Impact de l'ascite urinaire foetale sur le taux de beta2 microglobuline sérique dans les uropathies obstructives : à propos d'un cas.

We report a posterior urethral valves case diagnosed at 33 week's gestation on a fetus presenting with anamnios and urinary ascites. In this fetus, the serum beta2 microglobuline rate was high, suggesting a very poor renal prognosis. At 1-year-old, the creatinine rate is nearly normal. In case of urinary ascites, the serum beta2 microglobuline rate could be improved in relation with the transperitoneal reabsorption of this protein.

[Screening for Down syndrome using first-trimester combined screening followed by second trimester ultrasound examination in an unselected population]. / Dépistage de la trisomie 21 par le test combiné du premier trimestre suivi par l'échographie du second trimestre en population générale.

BACKGROUND: Recent studies have reported the efficacy of first trimester combined screening for Down Syndrome based on maternal age, serum markers (human chorionic gonadotropin, pregnancy-associated plasma protein A), and ultrasound measurement of fetal nuchal translucency. However, those do not incorporate the value of the widely accepted routine 20-22 week anomaly scan. STUDY DESIGN: We carried out a multi-centre, interventional study in the unselected population of a single health authority in order to assess the performance of first trimester combined screening, followed by routine second trimester ultrasound examination and/or screening by maternal serum markers (free beta-hCG and alpha-fetoprotein measurement or total hCG, alpha-fetoprotein and unconjugated estriol measurement) when incidentally performed. Detection and screen positive rates were estimated using a correction method for non verified issues. A cost analysis was also performed. RESULTS: During the study period, 14,934 women were included. Fifty-one cases of Down Syndrome were observed, giving a prevalence of 3.4 per 1000 pregnancies. Of these, 46 were diagnosed through first (N=41) or second (N=5) trimester screening. Among the 5 screen-negative Down syndrome cases, all were diagnosed postnatally after an uneventful pregnancy. Detection and screen positive rates of first trimester combined screening were 79.6% and 2.7%, respectively. These features reached 89.7 and 4.2%, respectively when combined with second trimester ultrasound screening. The average cost of the full screening procedure was 108 euro (120 $) per woman and the cost per diagnosed Down syndrome pregnancy was 7,118 euro (7,909 $). CONCLUSION: Our findings suggest that one pragmatic interventional two-step approach using first-trimester combined screening followed by second trimester detailed ultrasound examination is a suitable and acceptable option for Down syndrome screening in pregnancy.

[Contribution of three dimensional imaging techniques in the visualization of the fetal uterus]. / Contribution de l'imagerie tridimensionnelle échographique à la visualisation de l'utérus foetal.

The prenatal diagnosis of ambiguous genitalia requires a complete examination of the fetal anatomy to rule out any other congenital defects and the analysis of the fetal genotype. In addition any additional information on the anatomy of the internal genitalia, i.e. the presence or absence of fetal uterus, may be relevant to the prenatal evaluation of female pseudo-hermaphroditism. The recent development of 3D and 4D ultrasound technology may be relevant to a more clearly identification of the fetal uterus. Volume contrast imaging (VCI) provides high contrast images by the realization of thick slices of the region of interest (ROI) thereby providing a clearer picture of the fetal uterus. The multiplanar mode may also facilitate the differentiation of the fetal uterus from the other intra-pelvic organs by offering images in three perpendicular planes. Finally, the tomographic ultrasound imaging (TUI) mode offers the ability to display on a single panel numerous 2-dimensional sections, as obtained using computed tomography imaging.

Diprosopus associated with neural tube defect and facial cleft in the first trimester.

We report a case of diprosopus presenting with increased nuchal translucency of 5.3 mm at 14 weeks of gestation. Ultrasonographically, the fetus presented with micrognathia, anterior indentation of the cephalic pole, abnormal cerebral hemispheres with a cystic 4th ventricle and angulation of the spine. The fetal karyotype was normal (46,XX). Following termination of pregnancy, postmortem examination established the diagnosis of diprosopus tetraophthalmus with facial cleft of the 2 faces.

Prenatal diagnosis of hypoplasia of the corpus callosum in association with non-ketotic hyperglycinemia.

Abnormalities of the corpus callosum are often associated with a poor prognosis due to the anatomical defect itself and associated anomalies that include malformations and inherited metabolic disorders. We report a case of the prenatal diagnosis of hypoplasia of the corpus callosum that was associated with non-ketotic hyperglycinemia. Metabolic disorders are a known association with corpus callosum abnormalities and carry a dismal prognosis. A diagnosis of non-ketotic hyperglycinemia should be considered when a fetus presents with an abnormality of the corpus callosum. A literature search reviews other inherited diseases associated with hypoplasia of the corpus callosum.

Prenatal diagnosis of a 45,X male with a SRY-bearing chromosome 21.

Male phenotype associated with a 45,X karyotype is an infrequent finding. We present a case diagnosed prenatally on amniocentesis performed for maternal age. The male phenotype was associated with a translocation of a distal part of Yp including the pseudoautosomal SHOX gene and SRY gene on the short arm of a chromosome 21. By DNA analysis we could show that the X chromosome was of maternal origin and that the breakpoint was in interval 3 of the Y chromosome. Mechanisms and genetic counselling are discussed based on a review of published cases of 45,X and XX males.

Fetal serum beta2-microglobulin predicts postnatal renal function in bilateral uropathies.

BACKGROUND: Predicting postnatal renal function is crucial for the prenatal evaluation of fetal bilateral uropathies. Prenatal ultrasound can identify intrauterine terminal renal failure, but is not sensitive enough to identify those infants who would survive with an impaired renal function. Because it reflects fetal glomerular filtration, fetal serum beta2-microglobulin is a potential predictor of postnatal renal function. METHODS: Fetal serum beta2-microglobulin (beta2m) was assayed in 61 cases of bilateral or low obstructive uropathy, 74 controls, and 17 cases of bilateral renal agenesis, and was correlated with renal function. RESULTS: Fetal serum beta2m was 3.2 mg/L (range 1.5 to 4.7) in controls (N = 74), 9.5 mg/L (range 6.7 to 11.3) in bilateral renal agenesis (N = 17), 7 mg/L (5.1 to 10.6) in uropathy in which terminal renal failure resulted in termination of pregnancy (N = 26), and 3.7 mg/L (range 2.3 to 11.2) in live births with uropathy (N = 35). In the latter subgroup, fetal serum beta2m was significantly and positively correlated (r2 = 0.91) with postnatal serum creatinine. All survivors with a postnatal serum creatinine < or =50 micromol/L ha a fetal serum beta2m lower than 5 mg/L. Four of 6 survivors with a postnatal serum creatinine> 50 micromol/L had a fetal serum beta2m greater than 5 mg/L. CONCLUSION: Fetal serum beta2-microglobulin is a marker for renal function and predicts postnatal serum creatinine in bilateral or low fetal obstructive uropathy.

[Vesico-uterine fistula occurring after a normal labor in a patient with a scarred uterus]. / Fistule vésico-utérine survenant après un accouchement normal chez une patiente porteuse d'un utérus cicatriciel.

We report a vesico-uterine fistula occurring after vaginal delivery in a woman with previous cesarean section. Diagnosis of this rare complication, only 2 cases reported in the literature, is based on clinical findings and retrograde cystography. Medical treatment should be attempted first, but laparotomy is often required for resection of the fistula and simple suture of the bladder and the uterus.

Predictive value of fetal serum beta 2-microglobulin for neonatal renal function.

When fetal urinary-tract malformations (UTM) are discovered, management is based on the prediction of postnatal renal function, currently made by fetal urinary biochemistry and sonography. Serum beta 2-microglobulin has been used postnatally to estimate renal function and does not cross the placenta. We investigated the relation between fetal serum beta 2-microglobulin and renal function by comparing 64 unaffected fetuses and 15 fetuses with UTM. A beta 2-microglobulin above a 5.6 mg/L cut-off gave cross-validated sensitivity of 80.0%, specificity of 98.6%, a positive predictive value of 88.9%, and a negative predictive value of 97.1% for our cohort study.

[Prenatal diagnosis of spontaneous thrombosis of the umbilical artery during the third trimester of pregnancy. Two cases with surviving infants]. / Diagnostic anténatal d'une thrombose spontanée d'une artère du cordon ombilical au troisième trimestre de la grossesse. A propos de 2 observations avec enfants vivants.

Thrombosis of the umbilical artery was diagnosed in utero in two cases at the echography examination performed during the third trimester of gestation. The infants were born live and in good health. This is the first report of such antenatal diagnosis. The lack of prospective studies hinder the evaluation of fetal morbidity and mortality. Nevertheless, umbilical artery thrombosis is a high risk obstetrical situation since the potential risk of another thrombus in the second umbilical artery would lead to fetal death in utero. Careful monitoring is required with extraction of the fetus as soon as term allows or whenever the elements compromise fetal development.