Our study has shown that first-trimester risk assessment for trisomy 21 that includes a detailed ultrasound examination as well as NT measurement and is followed by cfDNA testing is associated with a significant reduction in the false-positive rate compared with FTCS. This approach obviates the need for maternal serum free β-human chorionic gonadotropin and pregnancy-associated plasma protein-A in screening for fetal aneuploidy. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Objective To examine the positive predictive value (PPV) of cfDNA screening for sex chromosome aneuploidies (SCA) in a large series of over 90 000 patients. Methods Retrospective study based on samples that were sent to Cenata, a private laboratory which uses the Harmony Prenatal Test. The SCA high‐risk results were stratified according to the method of diagnostic testing and according to karyotype result. Results The study population consisted of 144 cases. The CfDNA test indicated monosomy X, XXX, XXY, and XYY in 62, 37, 40, and 5 cases, respectively. The overall PPV was 38.9% (30.9‐47.4), 29.0% (18.2‐42.9) for monosomy X, 29.7% (15.9‐47.9) for 47,XXX, 57.5% (40.9‐73.0) for 47,XXY, and 80.0% (28.4‐99.5) for 47,XYY). A total of 112 (77.8%) women with a high‐risk result for SCAs opted for prenatal karyotyping. In this group, there were significant differences in the PPV if the karyotype was assessed by amniocentesis or by CVS: 29.5% vs 50.0%. This significant difference was driven by the monosomy X result which shows a significantly higher PPV in CVS (54.6% (23.4‐83.3) vs 17.1% (6.6‐33.6)). For the other SCAs, the differences were not significant. Conclusion PPV of an abnormal cfDNA test for SCAs is low, particularly for monosomy X. The confirmation rate depends on the type of confirmatory test.

Screening for fecal occult blood by means of guaiac tests has an unsatisfactory sensitivity for the detection of colorectal neoplasms. The immunological determination of human hemoglobin in feces has a higher sensitivity and specificity, but hemoglobin is degraded during its transport through the gastrointestinal tract. We compared the hemoglobin test to a newly developed immuno-chemiluminometric (ILMA) assay for quantifying the hemoglobin-haptoglobin complex in feces which shows high stability against degradation. From each of 621 patients with gastrointestinal complaints before scheduled colonoscopy we collected two 1-ml samples from a single stool; there were no dietary restrictions. The sensitivity for detecting colorectal carcinomas proved 87% with hemoglobin. With the hemoglobin-haptoglobin complex it was 87% at a cutoff level of 1.5 microg/g feces, 83% at 2.0 microg/g feces, and 78% at 2.5 and 3.0 microg/g feces. The sensitivity for detecting large adenomatous polyps was 54% with hemoglobin, 76% with the hemoglobin-haptoglobin complex at a cutoff point of 1.5 microg/g feces, 73% with the hemoglobin-haptoglobin complex at 2.0 and 2.5 microg/g feces, and 65% with the hemoglobin-haptoglobin complex at 3.0 microg/g feces. The optimal cutoff point for the hemoglobin-haptoglobin complex was estimated to be 2.0 microg/g stool. The specificity for hemoglobin (99%) was significantly higher than that for the hemoglobin-haptoglobin complex at 2.0 microg/g feces (96%). Immunological determination of the hemoglobin-haptoglobin complex in feces has a comparable sensitivity as the fecal hemoglobin assay for colorectal carcinomas and a significantly higher sensitivity for adenomatous polyps but a significantly lower specificity. Its use for colorectal cancer prevention is currently being evaluated in a screening study.

Objective To examine placental growth factor (PlGF)

Objective: To determine whether screening for trisomy 21 based on first-trimester combined screening (FTCS) with assessment of nasal bone (NB), tricuspid flow (TCF), and ductus venosus flow (DVF) results in similar false-positive rates compared to ultrasound and cell-free DNA (cfDNA) screening. Methods: This is a subanalysis of a prospective randomized controlled trial which was performed between October 2015 and December 2016. Pregnant women with a normal first-trimester ultrasound examination at 11 to 13 weeks’ gestation were randomized into two groups: (1) FTCS with assessment of the NB, TCF, and DVF (extended FTCS [eFTCS]), and (2) ultrasound + cfDNA screening. The false-positive rate in screening for trisomy 21 was defined as the primary outcome parameter. Results: The study population consisted of 688 women in each study arm. In the eFTCS group, the median delta fetal nuchal translucency thickness (NT) was 0.0 mm, free beta-hCG and PAPP-A were 0.96 and 1.11 MoM, and NB, TCF, and DVF PIV were abnormal in 0.9, 0.6, and 7.0% cases. In the ultrasound + cfDNA group, the median delta NT was 0.0 mm. In 10 pregnancies the cfDNA analysis was uninformative and the risk of trisomy 21 was based on eFTCS. There were no false-positive cases in the ultrasound + cfDNA group, whereas the false-positive rates were between 0.9 and 2.2% with eFTCS. Conclusion: Screening for trisomy 21 based on ultrasound + cfDNA has a lower false-positive rate than screening based on eFTCS.