Chẩn đoán trước sinh các Trisomy 21, 18 và 13 bằng kỹ thuật QF-PCR ở nhóm thai phụ có nguy cơ cao

Background: Prenatal diagnosis of trisomy 21, 18 and 13 plays an important role in improving population quality. This study aims to: (1) Determine the proportion of trisomies 21, 18 and 13 diagnosed by QF-PCR technique from amniotic cells of high-risk fetuses; and (2) Examine the association of diagnosed trisomies with some maternal and fetal characteristics.

Subjects and methods: 170 pregnant women with screening results at gestational age from 11 weeks to 13 weeks and 6 days were at high risk of trisomy 21, 18 and 13. Prenatal diagnosis was performed using QF-PCR technique with DNA extracted from amniotic cells.

Results: The rate of diagnosed trisomy was 9.4%; of which, trisomy 21 accounted for 68.8%, trisomy 18 accounted for 31.2%, and no trisomy 13 fetus was detected. There was a relationship between diagnosed trisomies and maternal age (optimal threshold 30.5 years) and nuchal translucency (optimal threshold 1.95 mm). The median MoM value of free β-hCG increased in the trisomy 21 group (4.35, p = 0.021) and decreased in the trisomy 18 group (0.13, p < 0.001) compared with the non-trisomy group (2.28). The median MoM value of serum PAPP-A decreased in the trisomy 18 group (0.14, p = 0.004) compared with the non-trisomy group (0.54).

Conclusion: Prenatal diagnosis by QF-PCR technique detected a significant rate of trisomies 21 and 18, with a correlation between prenatally diagnosed trisomies and maternal age, nuchal translucency, free β-hCG and serum PAPP-A.