The ductus venosus in early pregnancy and congenital anomalies

The ductus venosus (DV) is a tiny vessel leading oxygenated blood from the placenta to the fetal heart and its flow assessment has been used as an indicator of fetal acidemia. At 11 to 14 weeks, the fetuses with increased nuchal translucency also showing an abnormal DV blood flow were consistently found to be aneuploid. Early cardiac dysfunction, signaled by abnormal DV blood flow, was suggested as the underlying cause of increased nuchal translucency. Detection rates for aneuploidy with the use of DV blood flow studies range from 59 to 93% with 2 to 21% false-positive rates. In fetuses with normal karyotype, an abnormal DV flow pattern signals cardiac defects or adverse perinatal outcome. Copyright © 2004 John Wiley & Sons, Ltd.     

Trisomy 13 mosaicism: study of serial cytogenetic changes in a case from early pregnancy to infancy

We report a patient whose chorionic villus sampling showed a nonmosaic trisomy 13 [46,XX,der(13;13)(q10;q10)]. Subsequent amniocentesis and cordocentesis showed varying percentages of abnormal cells (77 and 78% in two amniocentesis; 14% in cordocentesis) and mosaic trisomy 13 was impressed. Prenatal fetal ultrasound scanning revealed only mild structural abnormalities (echogenic cardiac foci, transient lemon head, transient skin oedema). The mother chose to continue the pregnancy. Karyotyping of the cord blood, peripheral blood, umbilical cord, urine, and chorion were performed postpartum. The process of correction appeared to exist in the placenta (indirect evidence from coexistence of trisomy 13 [46,XX,der(13;13)(q10,q10)], euploidy [46,XX], aneuploidy [46,XX,–13, +mar], and monosomy 13 [45,XX,–13] in the chorion at birth). The baby had survived beyond eight months of age at the time of submission. Few structural abnormalities except low-set ears, absence of the 12th rib, and cardiomegaly with ventricular septal defect, were noted postnatally. The growth reached 95th percentile at the age of one month. Development milestones were not delayed at serial evaluations. Her ventricular septal defect was corrected surgically at the age of six months. Karyotypes of her skin fibroblasts, blood lymphocytes, and cardiac tissue were all normal [46,XX] at the time of surgery. Difficulties of the genetic counseling are also discussed. Copyright © 2004 John Wiley & Sons, Ltd.