ABSTRACT
OBJECTIVE: To Investigate the performance of prenatal screening for chromosomal abnormalities in first trimester. METHODS: Maternal serum were collected from 2 739 pregnant women between 11 and 14 weeks gestation. Free beta human chorionic gonadotrophin(beta-hCG), pregnancy-associated plasma protein(PAPP-A) from materal serum were measured using time resolved fluorescence immunoassay(TRFIA) and fetal nuchal translucency(NT) thickness were measured using transabdominal or transvaginal ultrasound. 22 chromosomal defects were diagnosed in 22 cases using karyotyping. The levels of three markers were analyzed among 22 cases and 870 controls. RESULTS: The level of three markers were significant difference between affected and unaffected pregnancies. In affected cases, the value or level of NT and free beta-hCG were higher, while the level of PAPP-A was lower. We found that screening for chromosomal defects using a combination of NT and serum biochemistry was associated with a detection rate of 91.67% for all types of chromosomal defects, with a false-positive rate of 11.16%. CONCLUSION: A combination of nuchal translucency measurement with materal serum biochemistry markers provides an effective method of screening for chromosomal defects.
