Screening For Down Syndrome In Pregnancies Research Articles

Editorial: Hereditary Cancer Risk Assessment: New Perspectives and Challenges for the Next-Gen Sequencing Era.

Editorial: Hereditary Cancer Risk Assessment: New Perspectives and Challenges for the Next-Gen Sequencing Era.

What Factors Impact upon a Woman's Decision to Undertake Genetic Cancer Testing?

Introduction: The advent of human genome project has lead to genetic tests that identify high-risk states for certain cancers. Many are privately marketed on the Internet. Despite the availability of tests, limited data has evaluated factors that lead to test uptake. The aim of the present study was to explore the attitudes of a cohort of new mothers toward uptake of a genetic cancer test with a 50% predictive value of cancer.Methods: A cross-sectional survey was undertaken. The project targeted women who had recently given birth at an Australian tertiary referral hospital. Women were asked about a theoretical blood test that detected an increased risk for the development of cancer. Attitudes and knowledge questionnaires were completed.Results: Of 232 consecutive women approached, 32 declined, giving a response rate of 86.2%. Only 63 (31.5%) women stated they would have the test. Absence of religious belief, higher level of education, better knowledge of terms used in genetics, an absence of concern over emotional, employment, and insurance discrimination, and previous acceptance of Down syndrome screening in pregnancy were each associated with significantly higher rate of test uptake in univariate analysis (all p < 0.03). In multivariate analysis, a lack of concern over discrimination and a history of having accepted Down syndrome screening in the previous pregnancy remained significantly associated with test uptake (all p < 0.0001).Conclusion: Concern over discrimination and having made a prior decision to have genetic testing were the principal factors associated with decision-making.

0638: Screening for Down Syndrome by Assessment of the Nasal Bone

Combined first trimester screening, with measurement of NT free-βhCG and PaPP-A is the standard of care for Down syndrome screening in pregnancy. The efficacy of this test, with a sensitivity of 90% and specificity of 95%, is significantly better than that for screening based on maternal age alone (sensitivity 30%; specificity 95%). The current challenge is to introduce other markers, ideally at the same gestational age, which will further improve the sensitivity and specificity of the test.

Dépistage de la trisomie 21 par le test combiné du premier trimestre suivi par l'échographie du second trimestre en population générale

Background Recent studies have reported the efficacy of first trimester combined screening for Down Syndrome based on maternal age, serum markers (human chorionic gonadotropin, pregnancy-associated plasma protein A), and ultrasound measurement of fetal nuchal translucency. However, those do not incorporate the value of the widely accepted routine 20–22 week anomaly scan. Study design We carried out a multi-centre, interventional study in the unselected population of a single health authority in order to assess the performance of first trimester combined screening, followed by routine second trimester ultrasound examination and/or screening by maternal serum markers (free β-hCG and alpha-fetoprotein measurement or total hCG, alpha-fetoprotein and unconjugated estriol measurement) when incidentally performed. Detection and screen positive rates were estimated using a correction method for non verified issues. A cost analysis was also performed. Results During the study period, 14,934 women were included. Fifty-one cases of Down Syndrome were observed, giving a prevalence of 3.4 per 1000 pregnancies. Of these, 46 were diagnosed through first ( N = 41) or second ( N = 5) trimester screening. Among the 5 screen-negative Down syndrome cases, all were diagnosed postnatally after an uneventful pregnancy. Detection and screen positive rates of first trimester combined screening were 79.6% and 2.7%, respectively. These features reached 89.7 and 4.2%, respectively when combined with second trimester ultrasound screening. The average cost of the full screening procedure was 108 € (120 $) per woman and the cost per diagnosed Down syndrome pregnancy was 7,118 € (7,909 $). Conclusion Our findings suggest that one pragmatic interventional two-step approach using first-trimester combined screening followed by second trimester detailed ultrasound examination is a suitable and acceptable option for Down syndrome screening in pregnancy.

Screening for Down syndrome using first-trimester combined screening followed by second-trimester ultrasound examination in an unselected population

Recent studies have reported the efficacy of first-trimester combined screening for Down syndrome based on maternal age, serum markers (human chorionic gonadotropin, pregnancy-associated plasma protein A), and ultrasound measurement of fetal nuchal translucency. However, those do not incorporate the value of the widely accepted routine 20-22 weeks' anomaly scan. We carried out a multicenter, interventional study in the unselected population of a single health authority in order to assess the performance of first-trimester combined screening, followed by routine second trimester ultrasound examination and/or screening by maternal serum markers (free beta-hCG and alpha-fetoprotein measurement or total hCG, alpha-fetoprotein, and unconjugated estriol measurement) when incidentally performed. Detection and screen positive rates were estimated using a correction method for nonverified issues. A cost analysis was also performed. During the study period, 14,934 women were included. Fifty-one cases of Down syndrome were observed, giving a prevalence of 3.4 per 1000 pregnancies. Of these, 46 were diagnosed through first (n = 41) or second (n = 5) trimester screening. Among the 5 screen-negative Down syndrome cases, all were diagnosed postnatally after an uneventful pregnancy. Detection and screen positive rates of first-trimester combined screening were 79.6% and 2.7%, respectively. These features reached 89.7%, and 4.2%, respectively, when combined with second-trimester ultrasound screening. The average cost of the full screening procedure was 108 euros (120 dollars) per woman and the cost per diagnosed Down syndrome pregnancy was 7,118 euros (7909 dollars). Our findings suggest that 1 pragmatic interventional 2-step approach using first-trimester combined screening followed by second-trimester detailed ultrasound examination is a suitable and acceptable option for Down syndrome screening in pregnancy.

Maternal serum inhibin levels in twin and singleton pregnancies conceived by assisted reproduction

To investigate whether second trimester serum inhibin levels differ in pregnancies conceived by assisted reproduction technology (ART). In Israel, serum samples from twin pregnancies were obtained for inhibin testing from women either referred for routine ultrasound monitoring, follow up after multi-fetal reduction or amniocentesis, largely for advanced maternal age. In the UK, inhibin had been tested prospectively in singleton and twin pregnancies of women having routine Down's syndrome (DS) screening. Results were available from 207 ART pregnancies: 170 singletons and 37 twins. This includes 15 twins from Israel, known to have been reduced from triplets to twins. Comparison was made with 4384 spontaneous pregnancies: 4334 singletons and 50 twins. Results were expressed in multiples of the gestation-specific median (MoM) for normal spontaneous pregnancies. In ART singletons, the median maternal inhibin level was higher (1.11 MoM) than in spontaneous singletons (0.99 MoM, P < 0.001, two-tail Wilcoxon Rank Sum Test). In twins, there was no material difference between ART and spontaneous pregnancies with medians of 1.98 and 2.18 MoM, respectively (P = 0.62). There was no effect of multi-fetal reduction, with medians of 1.76 and 1.81 MoM in reduced and non-reduced twins, respectively (P = 0.46). It appears that serum inhibin levels are increased on average in ART singletons but not in ART twin pregnancies. More data will be needed before deciding whether risk calculation parameters need to be altered when using inhibin for DS screening in pregnancy.

The effect of fetal gender on the false-positive rate of Down syndrome by maternal serum screening

(1) To further explore if there is a difference in maternal serum levels of alpha-fetoprotein (AFP), human chorionic gonadotrophin (hCG) and estriol (uE3) between fetal genders. (2) To determine if these differences influence false-positive rates of Down syndrome screening in pregnancies with male or female fetuses. This is a descriptive study of women screened at the Ontario Maternal Serum Screening program between 1993 and 1995. The women were grouped by fetal gender and ethnicity. Serum levels of the three markers and screening false-positive rates for Down syndrome were compared between fetal genders in women of different ethnicity respectively. Complete data were available for 110 306 pregnancies. In all three ethnic groups, MSAFP levels were significantly decreased and MShCG levels were significantly increased in women with female fetuses. The level of MSuE3 was similar between genders. The difference in false-positive rates of Down syndrome between genders was not statistically significant. This is the largest study comparing false-positive rates between fetal genders. In contrast to previous studies, the differences in the serum marker levels between fetal genders do not influence the false-positive rates for Down syndrome.