title: First trimester screening with free beta-hCG, PAPP-A and nuchal translucency in pregnancies conceived with assisted reproduction.
abstract: OBJECTIVE
  To evaluate the effect of in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) on free beta-human chorionic gonadotrophin (beta-hCG), pregnancy-associated plasma protein A (PAPP-A) and nuchal translucency (NT).
  
  
  METHODS
  First trimester maternal dried whole blood specimens from 74 singleton pregnancies (32 by IVF and 42 by ICSI) and 30 twin pregnancies (16 by IVF and 14 by ICSI) in which conception was achieved with assisted reproduction techniques were matched with five controls resulting in 370 singleton controls and 150 twin controls. NT was measured using the Fetal Medicine Foundation protocol. Free beta-hCG, PAPP-A and NT levels were compared between the IVF and control groups and between the ICSI and control groups using the Mann-Whitney U test.
  
  
  RESULTS
  In singleton pregnancies, the only significant difference was a 21% (95% CI: -35%--7%) reduction in PAPP-A in IVF cases. In twin pregnancies, the only significant difference was a 12% (95% CI: -34%--3%) reduction in NT in IVF cases. In singleton pregnancies, the false-positive rate for Down syndrome screening was 1.4% and 1.9% greater for the IVF and ICSI groups, respectively, compared to controls for a general screening population.
  
  
  CONCLUSIONS
  Patients undergoing assisted reproduction techniques should be counseled about the possibility of increased false-positive rates. Larger studies are needed to confirm this observation and to develop appropriate adjustment factors to reduce false-positive rates.
authors.affiliation: Centro di Diagnosi Prenatale, Palermo, Italy. orlandi@tin.it
authors.forename: Francesco
authors.initials: F
authors.lastname: Orlandi
authors.forename: Cinzia
authors.initials: C
authors.lastname: Rossi
authors.forename: A
authors.initials: A
authors.lastname: Allegra
authors.forename: David
authors.initials: D
authors.lastname: Krantz
authors.forename: Terrence
authors.initials: T
authors.lastname: Hallahan
authors.forename: Emanuela
authors.initials: E
authors.lastname: Orlandi
authors.forename: James
authors.initials: J
authors.lastname: Macri
mesh_terms: D015415:Biomarkers / Q000097:blood; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000097:blood*; D002887:Chromosomes, Human, Pair 18; D004314:Down Syndrome / Q000175:diagnosis; D005189:False Positive Reactions; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D009333:Neck / Q000000981:diagnostic imaging / Q000196:embryology*; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011266:Pregnancy-Associated Plasma Protein-A / Q000032:analysis*; D011446:Prospective Studies; D012016:Reference Values; D012680:Sensitivity and Specificity; D020554:Sperm Injections, Intracytoplasmic; D014314:Trisomy; D014427:Twins; D014463:Ultrasonography
chemical_list: D015415:Biomarkers; D018997:Chorionic Gonadotropin, beta Subunit, Human; D011266:Pregnancy-Associated Plasma Protein-A