title: Early elevations of the complement activation fragment C3a and adverse pregnancy outcomes.
abstract: OBJECTIVE
  To estimate whether elevations of complement C3a early in pregnancy are predictive of the subsequent development of adverse pregnancy outcomes.
  
  
  METHODS
  A plasma sample was obtained from each enrolled pregnant woman before 20 weeks of gestation. The cohort (n=1,002) was evaluated for the development of adverse pregnancy outcomes defined as hypertensive diseases of pregnancy (gestational hypertension or preeclampsia), preterm birth (before 37 weeks of gestation), premature rupture of the membranes, pregnancy loss (during the embryonic and fetal period), intrauterine growth restriction, and the composite outcome of any adverse outcome.
  
  
  RESULTS
  One or more adverse pregnancy outcomes occurred in 211 (21%) of the cohort. The mean levels (ng/mL) of C3a in early pregnancy were significantly (P=<.001) higher among women with one or more adverse outcomes (858±435) compared with women with an uncomplicated pregnancy (741±407). Adjusted for parity and prepregnancy body mass index, women with levels of C3a in the upper quartile in early pregnancy were three times more likely to have an adverse outcome later in pregnancy compared with women in the lowest quartile (95% confidence interval, 1.8-4.8; P<.001). The link between early elevated C3a levels and adverse pregnancy outcomes was driven primarily by individual significant (P<.05) associations of C3a with hypertensive diseases of pregnancy, preterm birth, and premature rupture of the membranes.
  
  
  CONCLUSIONS
  Elevated C3a as early as the first trimester of pregnancy is an independent predictive factor for adverse pregnancy outcomes, suggesting that complement-related inflammatory events in pregnancy contribute to the subsequent development of poor outcomes at later stages of pregnancy.
  
  
  METHODS
  II.
authors.affiliation: From the Department of Obstetrics and Gynecology, University of Colorado, School of Medicine, Aurora, Colorado.
authors.forename: Anne M
authors.initials: AM
authors.lastname: Lynch
authors.forename: Ronald S
authors.initials: RS
authors.lastname: Gibbs
authors.forename: James R
authors.initials: JR
authors.lastname: Murphy
authors.forename: Patricia C
authors.initials: PC
authors.lastname: Giclas
authors.forename: Jane E
authors.initials: JE
authors.lastname: Salmon
authors.forename: V Michael
authors.initials: VM
authors.lastname: Holers
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D015926:Complement C3a / Q000096:biosynthesis / Q000378:metabolism*; D005260:Female; D006801:Humans; D016015:Logistic Models; D011237:Predictive Value of Tests; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood*; D011256:Pregnancy Outcome; D011446:Prospective Studies
chemical_list: D015415:Biomarkers; D015926:Complement C3a