title: Amino acid composition of human uterine fluid: association with age, lifestyle and gynaecological pathology.
abstract: OBJECTIVE
  Do the amino acid levels of human uterine fluid vary with age, BMI, phase of menstrual cycle, benign pathology or diet?
  
  
  CONCLUSIONS
  The levels of 18 amino acids in human uterine fluid were shown to be affected only by maternal diet.
  
  
  BACKGROUND
  Murine, bovine and ovine uterine amino acid content has been reported, but no reliable data on the human exist. Murine studies have demonstrated that the intrauterine periconceptional nutritional environment is affected by maternal diet.
  
  
  METHODS
  Uterine secretions were aspirated from 56 women aged 18-45 years. The women were recruited preoperatively from gynaecological theatre operating schedules or hysterosalpingo-contrast-sonography (HyCoSy) lists. A proportion of these women had proven fertility; however, the majority were being investigated for subfertility. The BMI, gynaecological history and dietary pattern of these women were also assessed.
  
  
  METHODS
  Reverse phase high performance liquid chromatography was used to analyse the concentrations of 18 amino acids within the uterine fluid and blood serum. The results were analysed against the women's stage of cycle, age, BMI and diet.
  
  
  RESULTS
  The profile of 18 amino acids in uterine fluid was described. In total, human uterine fluid was observed to contain an amino acid concentration of 3.54 mM (interquartile range: 2.27-6.24 mM). The relative concentrations of 18 amino acids were not significantly altered by age, BMI, cycle phase or the presence of specific benign gynaecological pathologies. However, a diet identified by a validated scoring system as being less healthy was associated with higher concentrations of asparagine (P = 0.018), histidine (P = 0.011), serine (P = 0.033), glutamine (P = 0.049), valine (P = 0.025), phenylalanine (P = 0.019), isoleucine (P = 0.025) and leucine (P = 0.043) in the uterine fluid compared with a healthier diet, defined as one with a higher intake of fresh vegetables, fruit, whole-grain products and fish and a low intake of red and processed meat and high fat dairy products. There were no significant correlations between serum amino acid concentrations and those in the uterine fluid.
  
  
  CONCLUSIONS
  Our results enabled us to detect the effect of diet on the concentrations of amino acids in human uterine fluid; however, the study may not have had sufficient numbers to detect mild effects of BMI or age.
  
  
  CONCLUSIONS
  These findings increase our understanding of the nutritional environment encountered by the preimplantation embryo, and indicate how periconceptional diet may alter this. Given the importance of early embryo environment for programming of development and future health, this information may aid in the development of nutritional interventions aimed at optimizing the preimplantation phase of human embryo development in vivo.
  
  
  BACKGROUND
  This work was funded by the NIHR, the Medical Research Council (G0701153) and the University of Southampton and was supported by the NIHR BRC in Nutrition and Southampton University NHS Foundation Trust. The authors declare no conflicts of interest.
authors.affiliation: Centre for Human Development, Stem Cells & Regeneration, University of Southampton, Southampton SO16 6YD, UK Academic Unit of Human Development & Health, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK Complete Fertility Centre, Department of Obstetrics & Gynaecology, Princess Anne Hospital, Southampton SO16 6YD, UK NIHR BRC in Nutrition Southampton, Southampton SO16 6YD, UK.
authors.forename: Alexandra J
authors.initials: AJ
authors.lastname: Kermack
authors.affiliation: Centre for Human Development, Stem Cells & Regeneration, University of Southampton, Southampton SO16 6YD, UK Academic Unit of Human Development & Health, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: Finn-Sell
authors.affiliation: Academic Unit of Human Development & Health, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK Complete Fertility Centre, Department of Obstetrics & Gynaecology, Princess Anne Hospital, Southampton SO16 6YD, UK.
authors.forename: Ying C
authors.initials: YC
authors.lastname: Cheong
authors.affiliation: Complete Fertility Centre, Department of Obstetrics & Gynaecology, Princess Anne Hospital, Southampton SO16 6YD, UK.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Brook
authors.affiliation: Centre for Human Development, Stem Cells & Regeneration, University of Southampton, Southampton SO16 6YD, UK Academic Unit of Human Development & Health, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK.
authors.forename: Judith J
authors.initials: JJ
authors.lastname: Eckert
authors.affiliation: Academic Unit of Human Development & Health, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK Complete Fertility Centre, Department of Obstetrics & Gynaecology, Princess Anne Hospital, Southampton SO16 6YD, UK NIHR BRC in Nutrition Southampton, Southampton SO16 6YD, UK.
authors.forename: Nick S
authors.initials: NS
authors.lastname: Macklon
authors.affiliation: Centre for Human Development, Stem Cells & Regeneration, University of Southampton, Southampton SO16 6YD, UK Academic Unit of Human Development & Health, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK F.D.Houghton@soton.ac.uk.
authors.forename: Franchesca D
authors.initials: FD
authors.lastname: Houghton
mesh_terms: D000293:Adolescent; D000328:Adult; D000596:Amino Acids / Q000737:chemistry*; D001826:Body Fluids / Q000737:chemistry*; D015992:Body Mass Index; D004032:Diet; D005260:Female; D006801:Humans; D008019:Life Style; D008597:Menstrual Cycle; D008875:Middle Aged; D009765:Obesity / Q000150:complications; D057234:Preoperative Period; D014599:Uterus / Q000737:chemistry* / Q000473:pathology*; D055815:Young Adult
chemical_list: D000596:Amino Acids
keywords: BMI; amino acids; diet; human uterine fluid; menstrual cycle