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Chromosomal centromeric variants can be found in the course of a prenatal diagnosis. When following the discovery of fetal abnormalities at ultrasound examination, such variants may lead to some difficulties in genetic counseling. Here we describe a new heteromorphism implicating chromosome 12, found in a fetus with a suspicion of microcephaly, and we discuss its prognostic value., (Copyright 2003 S. Karger AG, Basel)

Integrins are adhesion molecules present in endometrial, decidual, and extravillous cytotrophoblast (EVCT) cells. They participate in cell-cell adhesion as well as in adhesion between cells and components of the extracellular matrix, and they play an important role in the endometrial phenotype change that occurs during the secretory phase, the first stage of implantation. At the beginning of pregnancy, the change in integrin expression is synchronized with the trophoblast attachment (embryo-endometrium interactions with integrins alpha(v)beta3, alpha4beta1, alpha6beta1, and alpha7beta1) and the embryo's invasion of the decidua (integrins alpha6beta4-->alpha5beta1-->alpha1beta1-->alpha4beta1 switch from proliferative to endovascular EVCT). Several diseases, including preeclampsia, intrauterine growth retardation caused by vascular problems and defective luteal phases, may be explained by anomalies in integrin patterns., (Copyright 2001 S. Karger AG, Basel)

The ontogenesis of the villous and vascular arborescence in normal pregnancy is reviewed. The emergence of the villi and the fetal vessels is described from early pregnancy to term together with the specializations of the villi, vessels and capillaries observed in the last trimester. The expression, localization and role of the angiogenic growth factors (FGF, VEGF, PLGF, HGF) are described and discussed. Pathological pregnancies with hyper- and hypocapillarization are related to altered oxygenation. The potential roles of growth factors are presented and hypotheses proposed which may provide a molecular basis for the development of the most frequent placental pathologies., (Copyright 2001 S. Karger AG, Basel)

In primates, fetal adrenal and placental steroidogenic enzymatic systems are complementary in a fetal-placental unit, synchronizing fetal maturation and myometrial activation in late gestation. Moreover, as hemochorial placentation characterizes rodents and primates, paracrine regulations between decidua and placenta are essential to the immunotolerance of the conceptus and its development. Thus, the decidual-placental unit remains in a striking state of decidual quiescence throughout gestation, and the reversal of this quiescence is thought to play a key role in myometrial stimulation and the onset of parturition. A comprehensive view of the control of myometrial contractility, through the interaction of paracrine and endocrine modifications in late gestation, is proposed. The failure of these mechanisms underlie prematurity and the use of fetal therapy in threatened preterm labor., (Copyright 2000 S. Karger AG, Basel.)

Cholestasis of pregnancy is a liver disorder that occurs during the second half of pregnancy, causing pruritus and elevated serum bile acid levels. Its etiology remains unknown but probably involves vascular and humoral immune responses, mediated by bile acids. This disorder is associated with substantially increased fetal morbidity and mortality. The most satisfactory treatment consists in delivering the fetus as soon as pulmonary maturation has occurred., (Copyright 2000 S. Karger AG, Basel.)

Objective: To emphasize the usefulness of fluorescence in situ hybridization (FISH) techniques on uncultured amniocytes for the diagnosis of abnormal mosaic karyotypes., Methods: In the course of three prenatal diagnoses, specific fluorescent probes, coding, respectively, for chromosomes X, Y, 18, 13, and 21, were applied on amniocyte preparations directly after amniocentesis. At least 50 nuclei were counted in each case. Parallel to the FISH procedure, cell cultures were set up in order to obtain karyotypes. FISH and cytogenetic results were then compared., Results: In each case, FISH showed an abnormal mosaic chromosomal constitution, 45,X/46,XX, which was related to the existence of tiny ring X chromosomes in karyotypes., Conclusion: Because very small ring X chromosomes can escape identification when standard cytogenetic techniques are used alone, we show that misdiagnosis can be avoided when FISH is performed beforehand., (Copyright 2000 S. Karger AG, Basel.)

A case of congenital bladder diverticulum diagnosed at 37 weeks of gestation (measured from the first day after the last day of the last menstrual period) is reported. Delivery took place 24 h later. A postnatal urologic work-up confirmed the diagnosis of asymptomatic congenital bladder diverticulum. The infant underwent laparotomic surgery at the age of 6 months, with an extravesical diverticulectomy and ureteral reimplantation. There were no complications. This is the first case reported in the literature of a prenatal diagnosis of a congenital bladder diverticulum. This new aspect allows early management and avoidance of the diagnostic meanders to which the discovery of a pelvic mass might lead, as well as the complications that can follow bladder diverticula.

The congenital mesoblastic nephroma is a very rare benign congenital renal tumor. It is the most common renal tumor before the age of 6 months (50%) and it constitutes only 5% of renal tumors before 15 years. The authors report a case of prenatal diagnosis of congenital mesoblastic nephroma revealed by an acute polyhydramnios at 33 weeks of pregnancy. After a preterm labor, the patient delivered at 35 weeks. The newborn underwent a radical nephrectomy. No recurrence was noticed at 10 months. This case of prenatal diagnosis is compared to the 12 cases previously reported. The prognosis of CMN depends on histologic findings, but also on the severity of prematurity induced by the polyhydramnios. The main treatment of this pathology if diagnosed during pregnancy remains the prevention of preterm labor, and after birth the removal of the kidney.

Fluorescence in situ hybridization (FISH) allows to diagnose aneuploidy in uncultured interphase nuclei. This rapid method of chromosomal analysis associated with cell-sorting techniques was realized on 47,XYY fetal cells isolated from maternal blood. Trophoblast cells were sorted by combining immunomagnetic removal of maternal lymphocytes and flow cytometry sorting using antitrophoblast monoclonal antibodies. Cells were sorted directly on slides and analyzed by FISH with a Y-centromeric probe. Among 1,387 examinable nuclei, 59 (4.25%) showed one single or two Y-specific domains.