OBJECTIVE To evaluate a novel ultrasound measurement, the prefrontal space ratio (PFSR), in second-trimester trisomy 21 and euploid fetuses. METHODS Stored three-dimensional volumes of fetal profiles from 26 trisomy 21 fetuses and 90 euploid fetuses at 15-25 weeks' gestation were examined. A line was drawn between the leading edge of the mandible and the maxilla (MM line) and extended in fron...

OBJECTIVE To assess the performance of screening for fetal trisomies 21, 18 and 13 by cell-free (cf) DNA analysis of maternal blood using a new method based on paired-end massively parallel shotgun sequencing (MPSS). METHODS This was a blinded study of plasma samples (1mL) obtained from 1000 women undergoing screening for fetal trisomies 21, 18 and 13 at 11-13 weeks' gestation. The study incl...

For antenatal diagnosis of Down syndrome (trisomy 21) and for the determination of parental origin of nondisjoined chromosome, we have evaluated a simple PCR based DNA diagnostic method where polymorphic allelic fragments were resolved in 6% polyacrylamide gel. Three families, DS5 , DS7 and DS9 , each with a single child with trisomy 21 were studied ,using two polymorphic microsatellite markers...

Analysis of the frequency data of each fingerprint type (arch, ulnar loop, radial loop, and whorl) of the parents of children with Trisomy 21 (Fathers: 71; Mothers: 128) born between 1965 and 1970 obtained from the Tokyo Medical and Dental University Hospital was carried out. Japanese controls were taken from dermatoglyphics data in Japan. We conducted the Friedman test on each type of fingerpr...

OBJECTIVE The primary objective of this study was to determine if isolated pyelectasis is a risk factor for trisomy 21. STUDY DESIGN Twelve thousand, six hundred and seventy-two unselected singleton fetuses were examined by prenatal ultrasound during the second trimester at a single institution. The sensitivity, specificity, positive predictive value, negative predictive value, and likelihood...

OBJECTIVE To examine the effectiveness of first-trimester fetal trisomy 21 screening using a combination of maternal age, nuchal translucency thickness (NT) and maternal serum free beta-human chorionic gonadotropin (beta-hCG) and pregnancy-associated plasma protein-A (PAPP-A) levels in a predominantly Chinese population in Hong Kong. METHODS This was a prospective study over a 1.5-year period...

OBJECTIVE To evaluate the correlation between reversed a-wave in ductus venosus at 16-20 weeks' gestation and trisomy 21 and adverse perinatal outcomes. MATERIALS AND METHODS Our study included 174 pregnant women who were under follow-up at a tertiary center between May and September 2010. Ductus venosus Doppler (DVD) measurements were obtained throughout the 6-month period from women who und...

OBJECTIVE To develop a new bioinformatic method in the noninvasive prenatal identification of common fetal aneuploidies using massively parallel sequencing on maternal plasma. METHODS Massively parallel sequencing was performed on plasma DNA samples from 108 pregnant women (median gestation: 12(+5) week) immediately before chorionic villus sampling (CVS) or amniocentesis. Data were analysed u...

OBJECTIVE To investigate the performance of first-trimester screening for aneuploidies by including assessment of the fetal nasal bone in the combined test of maternal age, fetal nuchal translucency (NT) thickness, fetal heart rate (FHR) and serum free beta-human chorionic gonadotropin (beta-hCG) and pregnancy-associated plasma protein-A (PAPP-A). METHODS Screening by the combined test was pe...