title: [Serum marker screening during the second trimester for prenatal diagnosis and predicting pregnancy outcome].
abstract: OBJECTIVE
  To explore the clinical value of screening the serum markers during the second trimester of pregnancy in preventing congenital birth defect and predicting the pregnancy outcome.
  
  
  METHODS
  Between November, 2011 and October, 2013, a total of 25 520 pregnant women (15-20+6 gestational weeks) underwent a screening test of triple serum markers including free beta-human chorionic gonadotrophin (free βhCG), alpha-fetoprotein (AFP), and unconjugated estriol (µE3) during the second semester of pregnancy. The women identified by the screening test as having high risks were referred to invasive prenatal diagnosis by amniocentesis, or to color Doppler ultrasound examination for suspected patent neural tube defect (NTD), and their pregnancy outcomes were followed up.
  
  
  RESULTS
  High-risk pregnancies were identified by the screening test in 4.91% (1254/25520) of the total cohort. Of the 818 patients receiving invasive prenatal diagnosis, the abnormal rate was 5.75% (47/818). The high-risk pregnancies identified by the screening test was associated with a significantly higher rate of abnormal outcomes compared with the low-risk pregnancies (1.91% vs 0.1%, P<0.01). Of the 210 high-risk cases of NTD, a definite diagnosis was established in 34 cases. We also found that pregnancies at an advanced age (>35 years) was associated with increased risks for trisomy 21 compared with those at younger ages (15% vs 1.65%P<0.01). The detection rate of abnormal karyotypes in pregnancies with an abnormal MoM value of a single marker was 3.17% (6/189).
  
  
  CONCLUSIONS
  Screening tests of serum markers during the second trimester of pregnancy can be helpful to identify fetal chromosomal and anatomical anomalies, predict unfavorable pregnancy outcomes, and prevent birth defects in pregnancies at an advanced age. The MoM value of a single marker in the second trimester can be indicative of potential chromosomal abnormalities.
authors.affiliation: Department of The Center of Prenatal Diagnosis, Wuxi Women and Children's Hospital Affiliated to Nanjing Medical University, Wuxi 214002, China.E-mail:Lilylan5930@sina.com.
authors.forename: Lan
authors.initials: L
authors.lastname: Yang
authors.forename: Li
authors.initials: L
authors.lastname: Zhao
authors.forename: Jingying
authors.initials: J
authors.lastname: Jiang
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
authors.forename: Hehua
authors.initials: H
authors.lastname: Tao
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.forename: Jinbao
authors.initials: J
authors.lastname: Wu
mesh_terms: D015415:Biomarkers / Q000097:blood*; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000097:blood; D002869:Chromosome Aberrations; D004314:Down Syndrome / Q000175:diagnosis; D004964:Estriol / Q000097:blood; D005260:Female; D006801:Humans; D009436:Neural Tube Defects / Q000175:diagnosis; D011247:Pregnancy; D011256:Pregnancy Outcome; D011262:Pregnancy Trimester, Second / Q000097:blood*; D011296:Prenatal Diagnosis; D000509:alpha-Fetoproteins / Q000032:analysis
chemical_list: D015415:Biomarkers; D018997:Chorionic Gonadotropin, beta Subunit, Human; D000509:alpha-Fetoproteins; D004964:Estriol