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[First trimester screening for Down syndrome at Prima facie. A 6-year survey]
P Roth1, J-P Bernard1, V Meyer2
1Service de maternité, hôpital universitaire Necker-Enfants-malades, 149, rue de Sèvres, 75015 Paris, France.
Insights
First-trimester screening for trisomy 21 effectively identifies 86.7% of cases using combined risk assessment. This method offers a 5.6% false positive rate for early detection.
Area of Science:
- Prenatal diagnostics
- Genetics
- Obstetrics
Background:
- First-trimester screening is crucial for detecting fetal aneuploidies.
- Combined risk assessment integrates multiple markers for improved accuracy.
- Trisomy 21 (Down syndrome) is a common target for prenatal screening.
Purpose of the Study:
- To evaluate the effectiveness of first-trimester combined risk screening for trisomy 21.
- To assess the detection rates and false positive rates of this screening method.
- To analyze screening results within the Prima facie structure based on French regulations.
Main Methods:
- A single-center retrospective study was conducted.
- Included patients with singleton pregnancies undergoing first-trimester screening between 2009 and 2014.
- Exclusions included pregnancies from embryo donation.
Main Results:
- 18,251 patients were analyzed.
- A trisomy 21 detection rate of 86.7% was achieved.
- The screening demonstrated a specificity of 94.4% with a 5.6% false positive rate.
Conclusions:
- First-trimester combined risk screening is an effective method for trisomy 21 detection.
- The study confirms the established detection and false positive rates for this screening approach.
- This approach aligns with regulatory guidelines for prenatal screening.
Objective:
To evaluate the results of screening for trisomy 21 by the combined risk of first trimester (as defined by the decree of June 23, 2009) in the Prima facie structure.
Methods:
Single center study involving all patients that were seen for first trimester screening at Prima facie with singleton living pregnancy, not obtained by embryo donation, between 1 January 2009 and 31 December 2014.
Results:
Eighteen thousand two hundred and fifty-one patients were included, of which underwent screening for trisomy 21 by the combined risk. One thousand and forty-six (6.1%) had a calculated risk higher than 1/250. Seventy-five were affected by trisomy 21, of whom 65 in the high risk group. The sensitivity and specificity of screening are 86.7% and 94.4%. The median nuchal translucency was 0.98 MoM.
Conclusions:
Screening for trisomy 21 by calculating the combined risk of first trimester enabled to detect 86.7% of trisomy 21 with a false positive rate of 5.6%.
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