Amniotic fluid peptides predict postnatal kidney survival in developmental kidney disease

Although a rare disease, bilateral congenital anomalies of the kidney and urinary tract (CAKUT) are the leading cause of end stage kidney disease in children. Ultrasound-based prenatal prediction of postnatal kidney survival in CAKUT pregnancies is far from accurate. To improve prediction, we conducted a prospective multicenter peptidome analysis of amniotic fluid spanning 140 evaluable fetuses with CAKUT. We identified a signature of 98 endogenous amniotic fluid peptides, mainly composed of fragments from extracellular matrix proteins and from the actin binding protein thymosin-β4. The peptide signature predicted postnatal kidney outcome with an area under the curve of 0.96 in the holdout validation set of patients with CAKUT with definite endpoint data. Additionally, this peptide signature was validated in a geographically independent sub-cohort of 12 patients (area under the curve 1.00) and displayed high specificity in non-CAKUT pregnancies (82 and 94% in 22 healthy fetuses and in 47 fetuses with congenital cytomegalovirus infection respectively). Change in amniotic fluid thymosin-β4 abundance was confirmed with ELISA. Knockout of thymosin-β4 in zebrafish altered proximal and distal tubule pronephros growth suggesting a possible role of thymosin β4 in fetal kidney development. Thus, recognition of the 98-peptide signature in amniotic fluid during diagnostic workup of prenatally detected fetuses with CAKUT can provide a long-sought evidence base for accurate management of the CAKUT disorder that is currently unavailable.

Impact of simulation-based prenatal invasive procedure training on professional practice, a preliminary study

INTRODUCTION

Amniocentesis and chorionic villus sampling remain the cornerstone of prenatal diagnosis. These procedures are associated with a risk of miscarriage estimated at approximately 0.5 %. Our team has developed a training model for performing simulation-based prenatal invasive procedures. Several simulation sessions are offered each year to obstetricians-gynecologists involved in fetal medicine in France and abroad. This simulation-based learning has already been conclusively evaluated according to levels I and II of the Kirkpatrick model. Here, we carried out a preliminary study according to level III: does participation in training in prenatal invasive procedures through simulation have an influence on professional practice?

METHODS

An anonymous online survey was sent to 82 obstetricians-gynecologists who participated in the training in prenatal invasive procedures at the Antoine Béclère maternity hospital between January 1^st, 2014 and December 31, 2018. This questionnaire, entitled "Evaluation of the professional impact of training in invasive procedures through simulation", included 20 quantitative and qualitative items.

RESULTS

48 (59 %) obstetricians-gynecologists responded to the questionnaire. 98 % of the participants considered that participation in the training had a significant impact on their professional practice. Half considered this impact to be major. 60 % of the former participants are now attached to a Multidisciplinary Center for Prenatal Diagnosis.

CONCLUSION

Participation in training is considered by former participants to have a significant impact on their professional practice. In order to finalize the evaluation of this learning, a study of the benefits for patients and their pregnancy should be discussed.

WDR81 mutations cause extreme microcephaly and impair mitotic progression in human fibroblasts and Drosophila neural stem cells

Microlissencephaly is a rare brain malformation characterized by congenital microcephaly and lissencephaly. Microlissencephaly is suspected to result from abnormalities in the proliferation or survival of neural progenitors. Despite the recent identification of six genes involved in microlissencephaly, the pathophysiological basis of this condition remains poorly understood. We performed trio-based whole exome sequencing in seven subjects from five non-consanguineous families who presented with either microcephaly or microlissencephaly. This led to the identification of compound heterozygous mutations in WDR81, a gene previously associated with cerebellar ataxia, intellectual disability and quadrupedal locomotion. Patient phenotypes ranged from severe microcephaly with extremely reduced gyration with pontocerebellar hypoplasia to moderate microcephaly with cerebellar atrophy. In patient fibroblast cells, WDR81 mutations were associated with increased mitotic index and delayed prometaphase/metaphase transition. Similarly, in vivo, we showed that knockdown of the WDR81 orthologue in Drosophila led to increased mitotic index of neural stem cells with delayed mitotic progression. In summary, we highlight the broad phenotypic spectrum of WDR81-related brain malformations, which include microcephaly with moderate to extremely reduced gyration and cerebellar anomalies. Our results suggest that WDR81 might have a role in mitosis that is conserved between Drosophila and humans.

De novo TUBB2B mutation causes fetal akinesia deformation sequence with microlissencephaly: An unusual presentation of tubulinopathy

Tubulinopathies are increasingly emerging major causes underlying complex cerebral malformations, particularly in case of microlissencephaly often associated with hypoplastic or absent corticospinal tracts. Fetal akinesia deformation sequence (FADS) refers to a clinically and genetically heterogeneous group of disorders with congenital malformations related to impaired fetal movement. We report on an early foetal case with FADS and microlissencephaly due to TUBB2B mutation. Neuropathological examination disclosed virtually absent cortical lamination, foci of neuronal overmigration into the leptomeningeal spaces, corpus callosum agenesis, cerebellar and brainstem hypoplasia and extremely severe hypoplasia of the spinal cord with no anterior and posterior horns and almost no motoneurons. At the cellular level, the p.Cys239Phe TUBB2B mutant leads to tubulin heterodimerization impairment, decreased ability to incorporate into the cytoskeleton, microtubule dynamics alteration, with an accelerated rate of depolymerization. To our knowledge, this is the first case of microlissencephaly to be reported presenting with a so severe and early form of FADS, highlighting the importance of tubulin mutation screening in the context of FADS with microlissencephaly.

[Impact of fetal urinary ascites on serum beta2 microglobuline in obstructive uropathies: a case report]

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.

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.

Screening for Down syndrome using first-trimester combined screening followed by second-trimester ultrasound examination in an unselected population

OBJECTIVE

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 weeks' anomaly scan.

STUDY DESIGN

We carried out a multicenter, 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 nonverified 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 euros (120 dollars) per woman and the cost per diagnosed Down syndrome pregnancy was 7,118 euros (7909 dollars).

CONCLUSION

Our findings suggest that 1 pragmatic interventional 2-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]

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 theFirst 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]

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]

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.