One Day Test

Bursting with joy and emotions, you are pregnant and just had your first prenatal visit. At the end of the visit, your doctor prescribed several tests including combined first trimester screening, designed in particular to estimate the risk of Trisomy 21 (Down Syndrome).

Since 2007, the Fetal Medicine Unit of the American Hospital of Paris has been building expertise in combined first semester pregnancy screening, known as the One Day Test. 
This combined test assesses not only the risk of Trisomy 21, but of Trisomy 13 and 18 as well. It detects 90 percent of affected fetuses. 
The One Day Test can be organized quickly over a half-day in a single location, and delivers same-day results. It includes:

  • Maternal blood test to evaluate first trimester maternal serum markers
  • First trimester ultrasound (anatomy scan) performed by a sonographer specialized in fetal medicine 
    • Measurement of nuchal translucency and analysis of other markers indicating a risk of chromosomal abnormality
    • Early screening for the main fetal abnormalities identifiable at this stage
    • Analysis of the uterine cervix and the placenta
  • Prenatal consultation with a specialist to discuss your screening results

After these exams and consultations, other tests designed to screen (in particular non-invasive prenatal maternal blood screening test) or diagnose (chorionic villus sampling or amniocentesis) may be prescribed if necessary.