title: Preconception folic acid treatment affects the microenvironment of the maturing oocyte in humans.
abstract: OBJECTIVE
  To investigate the influence of folic acid supplementation on the follicular fluid concentrations of folate and total homocysteine and their relationship to the diameter of the follicle.
  
  
  METHODS
  Observational study.
  
  
  METHODS
  Tertiary referral fertility clinic at the Erasmus MC, University Medical Center, Rotterdam, The Netherlands.
  
  
  METHODS
  Thirty-seven women undergoing IVF or intracytoplasmic sperm injection treatment.
  
  
  METHODS
  No interventions other than routine stimulation treatment and the recommendation of folic acid supplementation.
  
  
  METHODS
  Concentrations of folate and total homocysteine in monofollicular and pooled follicular fluid and the diameter of the follicle.
  
  
  RESULTS
  Folic acid supplementation significantly increased folate and decreased total homocysteine concentrations in pooled follicular fluid. In monofollicular fluid, folate concentrations only were significantly increased in supplemented women. The total homocysteine concentration appeared to be significantly correlated with the diameter of the follicle (r = 0.27). Samples from single follicles were less prone to artifacts in the measurements of the folate and total homocysteine concentration.
  
  
  CONCLUSIONS
  Preconception folic acid supplementation significantly alters both folate and total homocysteine concentrations in follicular fluid. The correlation between the diameter of the follicle and total homocysteine concentration in follicular fluid warrants further investigation.
authors.affiliation: Department of Obstetrics and Gynecology, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.
authors.forename: Jolanda C
authors.initials: JC
authors.lastname: Boxmeer
authors.forename: R Montserrate
authors.initials: RM
authors.lastname: Brouns
authors.forename: Jan
authors.initials: J
authors.lastname: Lindemans
authors.forename: Eric A P
authors.initials: EA
authors.lastname: Steegers
authors.forename: Elena
authors.initials: E
authors.lastname: Martini
authors.forename: Nick S
authors.initials: NS
authors.lastname: Macklon
authors.forename: Régine P M
authors.initials: RP
authors.lastname: Steegers-Theunissen
mesh_terms: D000328:Adult; D019587:Dietary Supplements; D005260:Female; D005307:Fertilization in Vitro; D005492:Folic Acid / Q000627:therapeutic use*; D015571:Follicular Fluid / Q000187:drug effects / Q000502:physiology; D006710:Homocysteine / Q000378:metabolism; D006801:Humans; D054315:Oocyte Retrieval; D009865:Oocytes / Q000187:drug effects / Q000502:physiology*; D006080:Ovarian Follicle / Q000166:cytology / Q000187:drug effects; D020554:Sperm Injections, Intracytoplasmic
chemical_list: D006710:Homocysteine; D005492:Folic Acid