title: Multicenter contraceptive efficacy trial of injectable testosterone undecanoate in Chinese men.
abstract: BACKGROUND
  Hormonal male contraceptive regimens effectively and reversibly suppress sperm production, but there are few large-scale efficacy studies.
  
  
  OBJECTIVE
  The safety, contraceptive efficacy, reversibility, and feasibility of injectable testosterone undecanoate (TU) in tea seed oil as a hormonal male contraceptive was assessed.
  
  
  METHODS
  This was a multicenter, phase III, contraceptive efficacy clinical trial.
  
  
  METHODS
  A total of 1045 healthy fertile Chinese men were recruited throughout China into the study.
  
  
  METHODS
  Injections of 500 mg TU were administered monthly for 30 months. A definition of severe oligozoospermia (< or =1 x 10(6)/ml) was used as a criterion of spermatogenic suppression and as the threshold for entering the contraceptive efficacy phase.
  
  
  METHODS
  The primary outcome was pregnancy rate in the partner. Other outcomes include: semen parameters, testis volumes, reproductive hormone levels, and safety laboratory tests.
  
  
  RESULTS
  Forty-three participants (4.8%) did not achieve azoospermia or severe oligozoospermia within the 6-month suppression phase. A total of 855 participants entered into the efficacy phase, and 733 participants completed monthly TU treatment and follow-up. There were nine pregnancies in 1554.1 person-years of exposure in the 24-month efficacy phase for a cumulative contraceptive failure rate of 1.1 per 100 men. The combined method failure rate was 6.1%, comprising 4.8% with inadequate suppression and 1.3% with postsuppression sperm rebound. No serious adverse events were reported. Spermatogenesis returned to the normal fertile reference range in all but two participants.
  
  
  CONCLUSIONS
  Monthly injection of 500 mg TU provides safe, effective, reversible, and reliable contraception in a high proportion of healthy fertile Chinese men.
authors.affiliation: Department of Male Clinic Research, National Research Institute for Family Planning, 12 Da Hui Si Road, Haidian District, Beijing 100081, China. ygu90@yahoo.cn
authors.forename: Yiqun
authors.initials: Y
authors.lastname: Gu
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Liang
authors.forename: Weixiong
authors.initials: W
authors.lastname: Wu
authors.forename: Minli
authors.initials: M
authors.lastname: Liu
authors.forename: Shuxiu
authors.initials: S
authors.lastname: Song
authors.forename: Lifa
authors.initials: L
authors.lastname: Cheng
authors.forename: Liwei
authors.initials: L
authors.lastname: Bo
authors.forename: Chengliang
authors.initials: C
authors.lastname: Xiong
authors.forename: Xinghai
authors.initials: X
authors.lastname: Wang
authors.forename: Xiaozhang
authors.initials: X
authors.lastname: Liu
authors.forename: Lin
authors.initials: L
authors.lastname: Peng
authors.forename: Kangshou
authors.initials: K
authors.lastname: Yao
mesh_terms: D000293:Adolescent; D000328:Adult; D000465:Algorithms; D002681:China; D003267:Contraception / Q000009:adverse effects / Q000379:methods*; D003272:Contraceptive Agents, Male / Q000008:administration & dosage / Q000009:adverse effects; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007273:Injections, Intramuscular; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D013076:Sperm Count; D013739:Testosterone / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives*; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D003272:Contraceptive Agents, Male; D013739:Testosterone; C010792:testosterone undecanoate