Prenatal screening and testing for trisomy 21 in twin pregnancies poses a number of challenges: the exact estimate of the a priori risk of trisomy 21, the choice of prenatal screening test and/or invasive techniques to employ for the diagnosis and the impact of the result on the options of treatment in case of discordant results within a twin pair or among multiples. These different aspects are...

present as an abnormal maternal screening test result or abnormal ultrasonography finding, this condition is not typically associated with structural abnormalities or abnormal maternal serum screening profiles. Therefore, prenatal diagnosis of Turner syndrome is complicated, and most cases are diagnosed incidentally or postnatally. In 1997, Lo et al. [3] demonstrated that fetal cell-free DNA (c...

Objective: To provide obstetrical and genetic health care practitioners with guidelines and recommendations for prenatal screening, diagnosis, and obstetrical management of fetal open and closed neural tube defects (OCNTD). Options: This review includes prenatal screening and diagnostic techniques currently being used for the detection of OCNTD including maternal serum alpha fetoprotein screeni...

Background. Beta thalassemia is one of the most common hereditary disorders worldwide. In Iran, it is frequently reported from northern and southern provinces. In order to prevent child birth to be affected by this complication, prenatal screening and diagnosis are carried out nationwide. However, in some instances, this program is unable to identify rare mutations leading to thalassemia. Case ...

Cytogenetic prenatal screening for Down's syndrome in the South West Region of England from 1975 to 1985 was reviewed. The use of amniocentesis increased, and for the years 1981 to 1985 averaged 29.4% of women 35 years or over at their estimated date of delivery. 58 pregnancies were terminated after karyotyping of amniotic fluid cells confirmed trisomy 21. 385,440 live births were born in the r...

Correspondence: Dr. C.A. Ionescu e-mail: antoniuginec@ yahoo.com After numerous clinical validation studies, non-invasive prenatal testing for fetal aneuploidy detection is now a clinical reality. While non-invasive prenatal testing was accepted due to the high accuracy for fetal trisomy (21, 18 and 13) detection, recent research showed that genome-wide analysis is able to detect other fetal an...

The term 'Non invasive prenatal testing' is used to describe the rapidly emerging molecular technologies related to cell free DNA assessment that are being applied to prenatal screening for Down syndrome and other chromosomal abnormalities. This technology is now available to Australian women through a number of off-shore laboratories. We review the basis of this method of testing, the literatu...

To analyze the characters of Down syndrome (DS) who failed to be diagnosed after prenatal screening and hope to be able to improve the programs of prenatal screening and reduce the missed diagnosis of DS. In this multicenter study, we collected the missed cases from 3 prenatal diagnosis centers and analyzed their characters. A total of 126 DS babies failed to be diagnosed after prenatal screeni...

Study objective—Evaluating the costs, eVects, and savings of several strategies for cystic fibrosis (CF) gene carrier screening. Design—A general model for evaluating prenatal, preconceptional, school, and neonatal carrier screening was constructed. For prenatal and preconceptional screening, two strategies were evaluated: single entry and double entry two step couple screening. Firstly, the Du...

OBJECTIVE To examine the cost-effectiveness of prenatal carrier screening for cystic fibrosis. METHODS A cost-benefit equation was developed that was based on the hypothesis that the cost of prenatal diagnosis required to diagnose and prevent one case of cystic fibrosis should be equal to or less than the lifetime cost generated from the birth of a neonate with cystic fibrosis. The formula wa...