First trimester genetic sonogram for screening fetal Down syndrome: A population-based study

Kuntharee Traisrisilp,Supatra Sirichotiyakul,Fuanglada Tongprasert,Kasemsri Srisupundit,Suchaya Luewan,Phudit Jatavan,Sirinart Sirilert,Theera Tongsong

doi:10.1016/j.tjog.2021.05.021

Kuntharee Traisrisilp, Supatra Sirichotiyakul + Show 6 more

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https://doi.org/10.1016/j.tjog.2021.05.021

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Abstract

ObjectiveTo evaluate the performance of first trimester sonomarkers in the detection of fetal Down syndrome among Thai pregnant women. Materials and methodsPregnant women at 11–13+6 weeks’ gestation underwent ultrasound examination for assessment of nuchal translucency (NT), nasal bone (NB), tricuspid regurgitation (TR), and abnormal ductus venosus (aDV) Doppler waveforms. The women were followed up for final outcomes. Fetal abnormalities other than trisomy 21 were excluded. The performances of each sonomarker and their combinations in predicting fetal Down syndrome were calculated. ResultsA total of 7820 pregnant women meeting the inclusion criteria were available for analysis, including 20 cases with fetal Down syndrome and 7800 unaffected cases. Of the four sonomarkers, NT, as a single sonomarker, had the highest detection rate (55.0% at a false positive rate of about 5%), whereas the remaining single sonomarkers had low detection rate (15–20%). The combination of all sonomarkers had the highest detection rate of 70% but the false positive rate was as high as 10.8%. The combination of NT and NB had a detection rate of 60% with an acceptable false positive rate of 6.9%, whereas the other combinations yielded relatively high false positive rates. ConclusionThe first trimester genetic sonogram in screening for Down syndrome among Asian women is acceptably effective and may be offered to some selected groups of the population. NT is the best sonomarker with a detection rate of 55% at 5% false positive rate and its combination with NB can improve performance with minimal increase in false positive rate.

Highlights

Down syndrome is one of the most common genetic diseases with a prevalence of 1 in 600 - 700 live births [1]
Because of its association with severe intellectual impairment and high frequency of structural defects, it is acceptable worldwide that Down syndrome screening should be provided to all pregnant women regardless of maternal age.[2]. Currently, several modalities are available for fetal Down syndrome screening, including cell-free fetal DNA in maternal plasma, maternal serum biomarkers in the first and second trimester, and ultrasound genetic screening
First trimester ultrasound for Down syndrome screening is usually performed at 11-13+6 weeks of gestation, and the sonomarkers include nuchal translucency (NT)(3-6), nasal bone (NB)(7-10), tricuspid regurgitation (TR)(11, 12), ductus venosus waveform (DV)(13-15) and frontomaxillary facial angle (FMA)(16-18)

Summary

Introduction

Down syndrome is one of the most common genetic diseases with a prevalence of 1 in 600 - 700 live births [1]. Because of its association with severe intellectual impairment and high frequency of structural defects, it is acceptable worldwide that Down syndrome screening should be provided to all pregnant women regardless of maternal age.[2] Currently, several modalities are available for fetal Down syndrome screening, including cell-free fetal DNA in maternal plasma, maternal serum biomarkers in the first and second trimester, and ultrasound genetic screening. Cell-free fetal DNA and maternal serum biomarkers, though highly effective, are not available in many parts of the world, especially developing countries. Ultrasound genetic screening, though less effective, is available worldwide and helpful in daily practice. To evaluate the performance of first trimester sonomarkers in the detection of fetal Down syndrome among Thai pregnant women

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