title: Development and in vitro testing of a new method of urine preparation for retrograde ejaculation; the Liverpool solution.
abstract: OBJECTIVE
  To design a new method for oral preparation of urine for sperm retrieval after retrograde ejaculation (RE) and to test the motility of sperm exposed to prepared and unprepared urine.
  
  
  METHODS
  In vitro testing of urine conditions and sperm motility.
  
  
  METHODS
  Assisted conception unit at a teaching hospital in the United Kingdom.
  
  
  METHODS
  Ten healthy volunteers to provide urine and sperm specimens from men attending the unit for semen analysis.
  
  
  METHODS
  Various solutions of sodium bicarbonate and sodium chloride were drunk by a single subject until a suitable regimen was achieved. This regimen (called the Liverpool solution) was then tested on 10 volunteers. Samples of sperm were then added to prepared urine, unprepared urine, and culture medium, and the motility was analyzed.
  
  
  METHODS
  Urinary pH and osmolarity, sperm motility.
  
  
  RESULTS
  Urine produced by the 10 volunteers had a mean pH of 7.47 (range, 7.23-7.79) and a mean osmolarity of 289 mOsmol/L (range, 225-412 mOsmol/L), similar to that of medium. The progressive motility of sperm exposed to the unprepared urine was reduced (42.4% of sperm in medium), whereas that in the prepared urine was similar to that in the control medium.
  
  
  CONCLUSIONS
  Liverpool solution can be used in any unit treating couples with RE, and it is a noninvasive and inexpensive regimen that may optimize urine pH and osmolarity for sperm survival after RE.
authors.affiliation: Hewitt Centre for Reproductive Medicine, Liverpool Women's Hospital, Liverpool, Merseyside, United Kingdom. tomaust@doctors.org.uk
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Aust
authors.forename: Stephanie
authors.initials: S
authors.lastname: Brookes
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Troup
authors.forename: William D
authors.initials: WD
authors.lastname: Fraser
authors.forename: D Iwan
authors.initials: DI
authors.lastname: Lewis-Jones
mesh_terms: D000284:Administration, Oral; D003470:Culture Media / Q000737:chemistry; D004326:Drinking; D004542:Ejaculation; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007248:Infertility, Male / Q000503:physiopathology / Q000628:therapy* / Q000652:urine; D008297:Male; D009994:Osmolar Concentration; D017693:Sodium Bicarbonate / Q000008:administration & dosage* / Q000652:urine; D012965:Sodium Chloride / Q000008:administration & dosage* / Q000652:urine; D013081:Sperm Motility; D013094:Spermatozoa; D013997:Time Factors; D014556:Urine / Q000737:chemistry / Q000166:cytology
chemical_list: D003470:Culture Media; D012965:Sodium Chloride; D017693:Sodium Bicarbonate