title: Risk factors for placenta accreta.
abstract: OBJECTIVE
  To identify risk factors associated with placenta accreta in a large cohort study.
  
  
  METHODS
  Data for this study came from the Taiwan Down Syndrome Screening Group, an ongoing project on feasibility of serum screening in an Asian population. Women who had serum screening for Down syndrome at 14-22 weeks' gestation using alpha-fetoprotein (AFP) and free beta-hCG between January 1994 and June 1997, and delivered in the same institution, were included (n = 10,672). Those who had multiple gestations (n = 200), overt diabetes (n = 11), or fetal malformations (n = 101) were excluded. If a woman was involved more than once, one randomly selected pregnancy was included in the analysis (n = 9349). Twenty-eight pregnancies were complicated by placenta accreta, diagnosed by clinical presentation (n = 26) or histologic confirmation (n = 2). Multiple logistic regression with adjustment for potentially confounding variables was used to identify independent risk factors for placenta accreta.
  
  
  RESULTS
  Women who had placenta previa (odds ratio [OR] 54.2; 95% confidence interval [CI] 17.8, 165.5) and second-trimester serum levels of AFP and free beta-hCG greater than 2.5 multiples of the median (OR 8.3; 95% CI 1.8, 39.3 and OR 3.9; 95% CI 1.5, 9.9, respectively), and were 35 years and older (OR 3.2; 95% CI 1.1, 9.4) were at increased risk of having placenta accreta.
  
  
  CONCLUSIONS
  Risk factors for placenta accreta include placenta previa, abnormally elevated second-trimester AFP and free beta-hCG levels, and advanced maternal age.
authors.affiliation: Department of Obstetrics and Gynecology, Chang Gung Memorial Hospital, Taipei, Taiwan.
authors.forename: T H
authors.initials: TH
authors.lastname: Hung
authors.forename: W Y
authors.initials: WY
authors.lastname: Shau
authors.forename: C C
authors.initials: CC
authors.lastname: Hsieh
authors.forename: T H
authors.initials: TH
authors.lastname: Chiu
authors.forename: J J
authors.initials: JJ
authors.lastname: Hsu
authors.forename: T T
authors.initials: TT
authors.lastname: Hsieh
mesh_terms: D000328:Adult; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000097:blood; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015999:Multivariate Analysis; D010921:Placenta Accreta / Q000097:blood / Q000453:epidemiology*; D011247:Pregnancy; D012307:Risk Factors; D000509:alpha-Fetoproteins / Q000032:analysis
chemical_list: D018997:Chorionic Gonadotropin, beta Subunit, Human; D000509:alpha-Fetoproteins