title: Fetal and maternal angiotensin (1-7) are associated with preterm birth.
abstract: BACKGROUND
  Recent studies show that preterm birth is associated with hypertension in later life. The renin-angiotensin system (RAS) during pregnancy influences fetal growth and development. In the current study, we investigated the impact of fetal as well as maternal angiotensin (1-7) [Ang (1-7)] and angiotensin II (Ang II) plasma concentrations on the risk of preterm birth.
  
  
  METHODS
  Three hundred and nine pregnant women were prospectively included into the study. The pregnant women were divided into two groups, for example, preterm birth of lower than 37 gestational weeks (n = 17) and full-term birth of 37 gestational weeks or more (n = 292). Maternal and neonatal plasma Ang (1-7) and Ang II concentrations were analyzed at birth from maternal venous blood and umbilical cord blood, respectively. Risk factors for premature birth were determined by multiple logistic regression analysis.
  
  
  RESULTS
  Fetal and maternal plasma Ang (1-7) concentrations in the preterm group were lower than those of the term group fetal Ang (1-7) preterm birth: 486.15 ± 337.34  ng/l and fetal Ang (1-7) term birth: 833.84 ± 698.12  ng/l and maternal Ang (1-7) preterm birth: 399.86 ± 218.93  ng/l; maternal Ang (1-7) term birth: 710.34 ± 598.22  ng/l. Multiple logistic regression analysis considering confounding factors revealed that preeclampsia (P < 0.001), premature rupture of membranes (P = 0.001), lower concentration of maternal Ang (1-7) (P = 0.013) and fetal plasma Ang (1-7) (P = 0.032) were independently associated with preterm birth. We could furthermore demonstrate that the maternal Ang (1-7)/Ang II ratio is independently associated with gestational hypertension or preeclampsia, factors causing preterm birth.
  
  
  CONCLUSIONS
  Lower concentrations of maternal and fetal Ang (1-7) are independently associated with preterm birth - a risk factor of hypertension in later life.
authors: aDepartment of Infectious Diseases bDepartment of Laboratory Medicine, the first Affiliated Hospital of Jinan University, Guangzhou cDepartment of Clinical Medicine, Medical College of Hunan Normal University, Changsha dDepartment of Obstetrics and Gynecology, the first Affiliated Hospital of Jinan University, Guangzhou, China eInstitute of Nutritional Science, University of Potsdam, Nuthetal, Potsdam, Germany *You-Peng Chen and Yong-Ping Lu contributed equally to the writing of this article.
authors: You-Peng
authors: YP
authors: Chen
authors: Yong-Ping
authors: YP
authors: Lu
authors: Jian
authors: J
authors: Li
authors: Zhi-Wei
authors: ZW
authors: Liu
authors: Wen-Jing
authors: WJ
authors: Chen
authors: Xu-Jing
authors: XJ
authors: Liang
authors: Xin
authors: X
authors: Chen
authors: Wang-Rong
authors: WR
authors: Wen
authors: Xiao-Min
authors: XM
authors: Xiao
authors: Christoph
authors: C
authors: Reichetzeder
authors: Berthold
authors: B
authors: Hocher
mesh_terms: D000328:Adult; D000803:Angiotensin I / Q000097:blood*; D000804:Angiotensin II / Q000097:blood; D005260:Female; D005312:Fetal Blood; D005333:Fetus / Q000378:metabolism*; D005865:Gestational Age; D006801:Humans; D046110:Hypertension, Pregnancy-Induced / Q000097:blood; D007231:Infant, Newborn; D010446:Peptide Fragments / Q000097:blood*; D011225:Pre-Eclampsia / Q000097:blood; D011247:Pregnancy; D047928:Premature Birth / Q000097:blood / Q000209:etiology*; D011446:Prospective Studies; D012084:Renin-Angiotensin System; D012307:Risk Factors; D047929:Term Birth / Q000097:blood
chemical_list: D010446:Peptide Fragments; D000804:Angiotensin II; D000803:Angiotensin I; C118790:angiotensin I (1-7)