title: Serological prenatal screening and diagnosis for Down syndrome.
abstract: OBJECTIVE
  This study aimed to review and summarize the recent first-trimester and second-trimester prenatal screening and sequential prenatal screening to analyze the role of the existing prenatal screening system in the secondary prevention of birth defects.
  
  
  METHODS
  This study included 3,665 cases of 14-20-week pregnant women that underwent prenatal screening using double serum alpha-fetoprotein (AFP) and beta-human chorionic gonadotropin (beta-hCG) and ultrasound screening; 512 cases of 9-12-week pregnant women underwent triple serological detection of serum beta-hCG, pregnancy-associated plasma protein A (PAPP-A), and nuchal translucency (NT) for early screening.
  
  
  RESULTS
  The overall screening was with a high-risk rate of 8.52%. Among 356 cases of high-risk pregnant women, a total of 308 cases underwent karyotype analysis of fetal amniotic fluid cells. Of these, five cases of trisomy 21, one case of trisomy 18 and one case of "47, XXY" were diagnosed; among 37 cases of neural tube defect (NTD)-affected high-risk pregnant women, one case of anencephalus, and one case of open spina bifida were diagnosed.
  
  
  CONCLUSIONS
  The overall detection rate for chromosome abnormalities was about 3.25% in the existing screening system, which could effectively prevent these seriously teratogenic fetuses from being born.
authors: Y
authors: Y
authors: Duan
authors: Y
authors: Y
authors: Li
authors: Q
authors: Q
authors: Xue
mesh_terms: D000328:Adult; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000097:blood*; D004314:Down Syndrome / Q000097:blood / Q000175:diagnosis*; D005260:Female; D006801:Humans; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011262:Pregnancy Trimester, Second; D011266:Pregnancy-Associated Plasma Protein-A / Q000378:metabolism*; D011296:Prenatal Diagnosis / Q000379:methods*; D012189:Retrospective Studies; D055815:Young Adult; D000509:alpha-Fetoproteins / Q000378:metabolism*
chemical_list: D018997:Chorionic Gonadotropin, beta Subunit, Human; D000509:alpha-Fetoproteins; D011266:Pregnancy-Associated Plasma Protein-A