Down syndrome (DS) is a birth defect with huge medical and social costs, caused by trisomy of whole or part of chromosome 21. It is the most prevalent genetic disease worldwide and the common genetic cause of intellectual disabilities appearing in about 1 in 400-1500 newborns. Although the syndrome had been described thousands of years before, it was named after John Langdon Down who described ...

OBJECTIVE To investigate the potential value of combined screening by maternal characteristics and medical history (maternal factors), estimated fetal weight (EFW), uterine artery pulsatility index (UtA-PI), mean arterial pressure (MAP) and serum levels of placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) at 30-34 weeks' gestation in the prediction of delivery of sm...

Objective: To provide family practitioners, obstetricians, and geneticists with guidelines and recommendations for prenatal diagnosis. Options: These guidelines apply to non-invasive screening techniques (including maternal serum screening and ultrasound) and to invasive techniques (including amniocentesis and chorionic villus sampling). Outcomes: Improved prenatal diagnosis of congenital abnor...

BACKGROUND Second-trimester cell-free fetal DNA (studied only in pregnancies with male fetuses) is higher in maternal serum samples from women carrying Down syndrome fetuses than in unaffected pregnancies. In this study we evaluated the potential performance of fetal DNA as a screening marker for Down syndrome. METHODS Data on maternal serum fetal DNA concentrations and the corresponding conc...

From January 1st 2013 to August 31st 2016, 24408 pregnant women received the first trimester Combined test and contingently offered second trimester maternal serum screening to identify those women who would most benefit from invasive prenatal diagnosis (IPD). The screening was based on first trimester cut-offs of ≥1:30 (IPD indicated), 1:31 to 1:899 (second trimester screening indicated) and ≤...

OBJECTIVE To compare the effectiveness of different screening policies for the antenatal detection of Down's syndrome. DESIGN Retrospective six year survey. SETTING Maternity units of eight districts. PARTICIPANTS Women who completed their pregnancies between 1 January 1994 and 31 December 1999 (155 501 deliveries). MAIN OUTCOME MEASURES Cases of Down's syndrome identified before 24 wee...

Background: For every pregnant woman, it is possible to have a child with chromosomal abnormalities. Although this possibility is not very high, by performing screening tests and considering the mother's background factors, we can largely realize the real extent of this possibility. Many comorbidities (like high blood pressure, diabetes, and obesity) and high-risk exposures (like alcohol consu...

OBJECTIVES To investigate whether the addition of maternal serum placental growth factor (PlGF) measured at 19-24 weeks' gestation improves the performance of screening for stillbirth that is achieved by a combination of maternal factors, fetal biometry and uterine artery pulsatility index (UtA-PI) and to evaluate the performance of screening with this model for all stillbirths and those due to...

BACKGROUND Serum human chorionic gonadotropin (hCG) and hCG free beta-subunit tests are used in combination with unconjugated estriol and alpha-fetoprotein in the triple screen test, and with the addition of inhibin-A in the quadruple marker test for detecting Down syndrome in the second trimester of pregnancy. These tests have a limited detection rate for Down syndrome: approximately 40% for h...

background: colorectal cancer (crc) is the third most common malignancy in iran. limited data are available on knowledge and barriers in regard to crc and screening tests in iran. the aim of  the study was to characterize knowledge, practice, and barriers toward crc and its screening tests among an iranian at‑risk population. methods: this cross‑sectional study was conducted with participation ...