Results of prenatal screening for fetal chromosome abnormality during the first trimester pregnancy in Guangzhou / 中华医学遗传学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To evaluate the efficiency of first trimester prenatal screening for fetal chromosome abnormality using maternal serum marker test and(or) plus nuchal translucency (NT) in Guangzhou region.</p><p><b>METHODS</b>The results of prenatal screening were retrospectively analyzed among 43 703 women with singleton pregnancies from January 2007 to September 2012. A total of 43 703 pregnancies between 9 and 13(+6) weeks of pregnancy were collected and analyzed for maternal serum pregnancy-associated plasma protein A (PAPPA), free β -human chorionic gonadotropin (free β -hCG) with or without crown-rump length (CRL). Nuchal translucency was measured by ultrasonographic scan between 11 and 13(+6) weeks of pregnancy. Gestational age was estimated by ultrasonographic scan. The risk values of Down syndrome (DS) and trisomy 18 were calculated using the software Lifcycle. Comparing the difference between the combined screening (PAPPA, free β -hCG and NT) and serum marker screening (PAPPA and free β -hCG).</p><p><b>RESULTS</b>Among the 43 703 pregnant women, screening showed that 1385 (3.17%) were Down syndrome positive and 55 (0.13%) were trisomy 18 positive. The final outcomes of pregnancy showed that 142 cases presented chromosomal abnormalities, of which 54 cases suffered from Down syndrome, 13 had trisomy 18, and 75 had other chromosome abnormalities. The total detection rate of Down syndrome and trisomy 18 were 83.33% and 76.92%, respectively.The positive rate is lower, and the detection rate is higher in combined screening group than serum marker screening group. The median PAPPA MoM was lower and the median free β -hCG MoM and NT measured value was higher in Down syndrome pregnancies than control group. The median PAPPA and free β -hCG MoM were lower and the median NT measured value was higher in trisomy 18 pregnancies than control group.</p><p><b>CONCLUSION</b>The first trimester prenatal screening can effectively detect Down syndrome and trisomy 18 pregnancy. The combined screening method is superior to the serum marker screening and is the preferred strategy in the first trimester prenatal screening.</p>