title: Chronic hypertension and the risk for adverse pregnancy outcome after superimposed pre-eclampsia.
abstract: OBJECTIVE
  To determine the risk factors and pregnancy outcome of patients with chronic hypertension during pregnancy after controlling for superimposed preeclampsia.
  
  
  METHODS
  A comparison of all singleton term (>36 weeks) deliveries occurring between 1988 and 1999, with and without chronic hypertension, was performed. Stratified analyses, using the Mantel-Haenszel technique, and a multiple logistic regression model were performed to control for confounders.
  
  
  RESULTS
  Chronic hypertension complicated 1.6% (n=1807) of all deliveries included in the study (n=113156). Using a multivariable analysis, the following factors were found to be independently associated with chronic hypertension: maternal age >40 years (OR=3.1; 95% CI 2.7-3.6), diabetes mellitus (OR=3.6; 95% CI 3.3-4.1), recurrent abortions (OR=1.5; 95% CI 1.3-1.8), infertility treatment (OR=2.9; 95% CI 2.3-3.7), and previous cesarean delivery (CD; OR=1.8 CI 1.6-2.0). After adjustment for superimposed preeclampsia, using the Mantel-Haenszel technique, pregnancies complicated with chronic hypertension had higher rates of CD (OR=2.7; 95% CI 2.4-3.0), intra uterine growth restriction (OR=1.7; 95% CI 1.3-2.2), perinatal mortality (OR=1.6; 95% CI 1.01-2.6) and post-partum hemorrhage (OR=2.2; 95% CI 1.4-3.7).
  
  
  CONCLUSIONS
  Chronic hypertension is associated with adverse pregnancy outcome, regardless of superimposed preeclampsia.
authors.affiliation: Faculty of Health Sciences, Ben Gurion University of the Negev, Beer-Sheva, Israel.
authors.forename: M
authors.initials: M
authors.lastname: Vanek
authors.forename: E
authors.initials: E
authors.lastname: Sheiner
authors.forename: A
authors.initials: A
authors.lastname: Levy
authors.forename: M
authors.initials: M
authors.lastname: Mazor
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001724:Birth Weight; D016022:Case-Control Studies; D002908:Chronic Disease; D005260:Female; D005865:Gestational Age; D006801:Humans; D006973:Hypertension / Q000150:complications*; D016015:Logistic Models; D011225:Pre-Eclampsia / Q000209:etiology*; D011247:Pregnancy; D011256:Pregnancy Outcome; D012189:Retrospective Studies; D012307:Risk Factors