title: PP179. The influence of prior abortion on rates of gestational hypertension/pre-eclampsia and spontaneous preterm delivery in nulliparous women.
abstract: BACKGROUND
  Gestational hypertension/preeclampsia (GH) is clearly a heterogeneous condition of which the pathogenesis could be different in women with various risk factors. Nulliparity is a known risk factor for GH, however a previous abortion (spontaneous or induced) may be associated with a lower risk of GH.
  
  
  OBJECTIVE
  To examine the effect of abortion history on rates of GH and spontaneous preterm delivery (SPTD) and in nulliparous women.
  
  
  METHODS
  Nulliparous women with an initial prenatal screening at <13 weeks' gestation and a current singleton gestation delivering between 6/2006 and 6/2011 that voluntarily enrolled for risk assessment-case management services were identified from a database of clinical information. Excluded were women reporting a history of both spontaneous (SAB) and induced (IAB) abortions, or with a priori diagnosis of diabetes. Rates of SPTD and GH were compared between women with SAB or IAB history (AB group) and a reference group of primigravid women using Pearson's chi-square, Student's t, Kruskal-Wallis H, and Mann-Whitney U statistics.
  
  
  RESULTS
  Of the 75,487 women studied, 5.7% (n=4288) reported a history of IAB and 24.3% (n=18,328) reported a history of SAB. Overall, 301 women (0.4%) experienced a SAB at <20 weeks in the index pregnancy. Of those 75,186 with delivery ⩾20 weeks, the incidence of SPTD was 6.1% in controls vs. 6.0% in the IAB/SAB group (p=0.550). Rates of GH were 10.2% in controls vs. 8.0% (p<0.001) in the AB group despite the AB group having significantly (p<0.001) higher rates of women of African-American race (8.5% vs. 5.5%); age >34years (23.9% vs. 10.0%); and obesity (19.6% vs. 16.6%). For women with >2 AB's significant differences were observed in rates of SPTD vs. controls (8.2% vs. 6.0%, p<0.001), but rates of GH were similar (9.2% vs. 10.2%, p=0.188). (1)p<0.001 vs. 0 AB group.
  
  
  CONCLUSIONS
  In nulliparous women, prior AB is associated with a reduction in risk for GH. Risk for SPTD increases only in those with >2 prior AB's.
authors.affiliation: Perinatal Diagnostic Center, Central Baptist Hospital, Lexington, KY, United States.
authors.forename: K
authors.initials: K
authors.lastname: Clark
authors.affiliation: Perinatal Diagnostic Center, Central Baptist Hospital, Lexington, KY, United States.
authors.forename: J R
authors.initials: JR
authors.lastname: Barton
authors.affiliation: Alere Health, Atlanta, GA, United States.
authors.forename: N
authors.initials: N
authors.lastname: Istwan
authors.affiliation: Alere Health, Atlanta, GA, United States.
authors.forename: D
authors.initials: D
authors.lastname: Rhea
authors.affiliation: Alere Health, Atlanta, GA, United States.
authors.forename: C
authors.initials: C
authors.lastname: Desch
authors.affiliation: College of Charleston, Charleston, SC, United States.
authors.forename: A
authors.initials: A
authors.lastname: Sibai
authors.affiliation: Maternal-Fetal Medicine, University of Cincinnati, Cincinnati, OH, United States.
authors.forename: B M
authors.initials: BM
authors.lastname: Sibai