title: The efficacy of test tube warming devices used during oocyte retrieval for IVF.
abstract: OBJECTIVE
  To investigate whether commonly used test tube warming devices maintain a constant temperature in follicular fluid aspirates.
  
  
  METHODS
  By using a digital thermocouple, temperature was measured and comparisons were made between an analog dry block heater, a digital dry block heater, and a thermostatic test tube heater.
  
  
  RESULTS
  For small fluid volumes, temperature in the block heaters increased above 37 degrees C after being in the block for over 2 min. The thermostatic heater maintained a constant temperature, but this was below the factory setting of 36.9 degrees C. Temperature maintenance was influenced by fluid volume in each tube.
  
  
  CONCLUSIONS
  One of the key factors in the handling of gametes and embryos is the maintenance of constant temperature. Test tube warming devices require verification of their ability to maintain fluid at the desired temperature. Temperature may vary with fluid volume and the type of test tube warming device used.
authors.affiliation: Department of Obstetrics and Gynaecology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong. queeniey@cuhk.edu.hk
authors.forename: Queenie Sum Yee
authors.initials: QS
authors.lastname: Yeung
authors.forename: Christine May
authors.initials: CM
authors.lastname: Briton-Jones
authors.forename: Grace Ching Ching
authors.initials: GC
authors.lastname: Tjer
authors.forename: Tony Tak Yu
authors.initials: TT
authors.lastname: Chiu
authors.forename: Christopher
authors.initials: C
authors.lastname: Haines
mesh_terms: D000328:Adult; D004867:Equipment Design; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods*; D006801:Humans; D018587:Oocyte Donation / Q000379:methods*; D011247:Pregnancy; D013048:Specimen Handling; D013696:Temperature