Is there still a role for nuchal translucency measurement in the changing paradigm of first trimester screening?

Objectives

To give an overview of the genetic and structural abnormalities occurring in fetuses with nuchal translucency (NT) measurement exceeding the 95th percentile at first-trimester screening and to investigate which of these abnormalities would be missed if cell-free fetal DNA (cfDNA) were used as a first-tier screening test for chromosomal abnormalities.

Methods

This is a national study including 1901 pregnancies with NT≥95th percentile referred to seven university hospitals in the Netherlands between 1 January 2010 and 1 January 2016. All cases with unknown pregnancy outcome were excluded. Results of detailed ultrasound examinations, karyotyping, genotyping, pregnancy and neonatal outcomes, investigation by a clinical geneticist and post-mortem investigations were collected.

Results

In total, 821 (43%) pregnancies had at least one abnormality. The rate of abnormalities was 21% for fetuses with NT between 95^th and 99^th percentile and 62% for fetuses with NT≥99^th percentile. Prevalence of single-gene disorders, submicroscopic, chromosomal and structural abnormalities was 2%, 2%, 30% and 9%, respectively.

Conclusion

Although cfDNA is superior to the combined test, especially for the detection of trisomy 21, 34% of the congenital abnormalities occurring in fetuses with increased NT may remain undetected in the first trimester of pregnancy, unless cfDNA is used in combination with fetal sonographic assessment, including NT measurement.     

Handling Techniques: The Influence of Weight and Height for Experts and Novices

The purpose of this study was to evaluate the influence of the weight of the load (12 kg, 22 kg) and of the height of the grasp (high: 126 cm; middle: 64 cm and 95 cm; low: 33 cm) on the handling techniques adopted by six experienced handlers and six novices having only limited handling experience during a free box-handling task. Each subject had to transfer two sets of 16 boxes from a platform to a four-wheel cart. The observations dealt with the position of the subject at the beginning of transfer and at deposit (position of the back, knees and feet, pelvic orientation, position of the hands), his way of moving during the transfer (position of the feet), and his way of positioning and moving the box during handling (tilt of the box, impulse given to the box, grip change). The results show that the weight and the height of grasp/deposit had an influence on the techniques adopted by expert handlers and novices. Some of these variations are common to both groups but many of them are not, such as the position of the knees, the grips and the position of the box. This study suggests that there is not one method that is suitable for all situations, and that expert handlers may have learned how to adjust their methods to the working environment. A better understanding of the experts’ techniques could help in redesigning efficient training programs.     

Integrated spatial health assessment of yellow perch (Perca flavescens) populations from the St. Lawrence River (QC,Canada), part B: cellular and transcriptomic effects

Environmental Science and Pollution Research - Multi-biological level assessments have become great tools to evaluate the health of aquatic ecosystems. Using this approach, a complementary study...     

Hyperactivity and tree-top disease induced by the baculovirus AcMNPV in Spodoptera exigua larvae are governed by independent mechanisms

Although many parasites are known to manipulate the behavior of their hosts, the mechanisms underlying such manipulations are largely unknown. Baculoviruses manipulate the behavior of caterpillar hosts by inducing hyperactivity and by inducing climbing behavior leading to death at elevated positions (tree-top disease or Wipfelkrankheit). Whether hyperactivity and tree-top disease are independent manipulative strategies of the virus is unclear. Recently, we demonstrated the involvement of the protein tyrosine phosphatase (ptp) gene of the baculovirus Autographa californica multiple nucleopolyhedrovirus (AcMNPV) in the induction of hyperactivity in Spodoptera exigua larvae. Here we show that AcMNPV ptp is not required for tree-top disease, indicating that in S. exigua baculovirus-induced hyperactivity and tree-top disease are independently induced behaviors that are governed by distinct mechanisms.     

Intermittent absent and reversed umbilical artery flows in appropriately grown monochorionic diamniotic twins in relation to proximate cord insertion: A harmful combination?

Objective

To compare the prevalence of intermittent absent or reversed end-diastolic flow (iAREDF) in the umbilical artery in appropriately grown monochorionic diamniotic (MCDA) pregnancies with and without proximate cord insertion (PCI), and to evaluate pregnancy outcome.

Methods

The prevalence of iAREDF in MCDA pregnancies with PCI (n = 11) was compared with a control group without PCI (n = 33). PCI was defined as a distance between the cord insertions below the fifth percentile. Placental sharing, number, and diameter of anastomoses were assessed by placental examination. Pregnancy outcome was evaluated.

Results

iAREDF was present in 7/11 PCI pregnancies, compared with 0/33 in the control group (P ≤ .01). All PCI pregnancies and 94% of controls had arterioarterial (AA)-anastomoses (P = .56), the diameter was larger in the PCI group, respectively 3.3 vs 2.1 mm (P = .03). Three cases with iAREDF had adverse outcome, two resulted in fetal death of which one with brain damage in the co-twin, another underwent early premature emergency section for fetal distress.

Conclusion

iAREDF occurs in a large proportion of MCDA pregnancies with PCI and is related to the diameter of the AA anastomosis. We hypothesize that iAREDF in appropriately grown MCDA twin pregnancies reflects an unstable hemodynamic balance with an increased risk for fetal deterioration. Whether outcome in these pregnancies can be improved by altered management requires further investigation.