title: The balance between human maternal plasma angiotensin II and angiotensin 1-7 levels in early gestation pregnancy is influenced by fetal sex.
abstract: OBJECTIVE
  There are fetal sex-associated differences in the circulating maternal renin-angiotensin system (RAS) in early pregnancy.
  
  
  METHODS
  Plasma prorenin, angiotensin (Ang) II, Ang 1-7 and angiotensin-converting enzyme (ACE) concentrations were measured at 15 weeks' gestation in 131 women with uncomplicated pregnancies from the Adelaide SCOPE cohort. Uterine and umbilical artery Doppler sonography was performed at 20 weeks' gestation.
  
  
  RESULTS
  At 15 weeks, women bearing female fetuses had higher maternal Ang II concentrations (p = 0.017) and lower Ang 1-7 to Ang II ratios (p = 0.016) than women bearing males. In women with male fetuses, Ang II positively correlated with birth weight (p = 0.028) and prorenin negatively correlated with placental weight (p = 0.014). Female fetuses had higher umbilical artery resistance indices (p = 0.019) that were related to maternal prorenin concentrations (p = 0.007).
  
  
  CONCLUSIONS
  In early human pregnancy, the maternal RAS is influenced by fetal sex. The lower Ang 1-7 to Ang II ratios in women with female fetuses may contribute to the lower maternal peripheral microvascular flow as described previously and the lack of any positive effect of Ang II on fetal growth, as seen in women with male fetuses.
authors: Hunter Medical Research Institute, University of Newcastle, Australia Robinson Institute, University of Adelaide, Australia.
authors: Shane D
authors: SD
authors: Sykes
authors: Hunter Medical Research Institute, University of Newcastle, Australia.
authors: Kirsty G
authors: KG
authors: Pringle
authors: Robinson Institute, University of Adelaide, Australia.
authors: Ang
authors: A
authors: Zhou
authors: Robinson Institute, University of Adelaide, Australia Women's and Children's Division, Lyell McEwin Hospital, Australia.
authors: Gustaaf A
authors: GA
authors: Dekker
authors: Robinson Institute, University of Adelaide, Australia.
authors: Claire T
authors: CT
authors: Roberts
authors: Hunter Medical Research Institute, University of Newcastle, Australia eugenie.lumbers@newcastle.edu.au.
authors: Eugenie R
authors: ER
authors: Lumbers
mesh_terms: D000803:Angiotensin I / Q000097:blood*; D000804:Angiotensin II / Q000097:blood*; D002097:C-Reactive Protein / Q000378:metabolism; D005260:Female; D005333:Fetus / Q000378:metabolism*; D006801:Humans; D008297:Male; D008429:Maternal Welfare; D010446:Peptide Fragments / Q000097:blood*; D007703:Peptidyl-Dipeptidase A / Q000378:metabolism; D011247:Pregnancy; D012084:Renin-Angiotensin System; D012727:Sex Characteristics
chemical_list: D010446:Peptide Fragments; D000804:Angiotensin II; D002097:C-Reactive Protein; D000803:Angiotensin I; D007703:Peptidyl-Dipeptidase A; C118790:angiotensin I (1-7)
keywords: Pregnancy; angiotensin peptides; angiotensin-converting enzyme; prorenin; sexual dimorphism