title: [Effect and safety of L-carnitine in the treatment of idiopathic oligoasthenozoospermia: a systemic review].
abstract: OBJECTIVE
  To evaluate the effect and safety of L-carnitine in the treatment of idiopathic oligoasthenozoospermia based on current clinical evidence.
  
  
  METHODS
  We searched the Cochrane Library, PubMed, MEDLINE, EMBASE, CNKI, VIP, CBM and Wanfang Database from the establishment to April 2014 for the published literature on the treatment of idiopathic oligoasthenozoospermia with L-carnitine. We conducted literature screening, data extraction, and assessment of the methodological quality of the included trials according to the inclusion and exclusion criteria, followed by statistical analysis with the RevMan 5. 2 software.
  
  
  RESULTS
  Seven randomized controlled trials involving 751 patients with idiopathic oligoasthenozoospermia met the inclusion criteria, and 678 of them were included in the meta-analysis. L-carnitine treatment achieved a significantly increased rate of spontaneous pregnancy as compared with the control group (RR = 3.2, 95% CI 1.74 to 5.87, P = 0.0002). After 12-16 and 24-26 weeks of medication, total sperm motility (WMD = 5.21, 95% CI 2.78 to 7.64, P < 0.0001 and WMD = 9.29, 95% CI 1.28 to 17.29, P = 0.02) and the percentage of progressively motile sperm (WMD = 12.44, 95% CI 4.58 to 20.31, P = 0.002 and WMD = 9.76, 95% CI 3.56 to 15.97, P = 0.002) were remarkably higher than those in the control group, but no statistically significant differences were observed in sperm concentration between the two groups (WMD = 4.91, 95% CI -2.63 to 12.45, P = 0.2 and WMD = 0.93, 95% CI -3.48 to 5.34, P = 0.68). After 12-16 weeks of treatment, the percentage of morphologically abnormal sperm was markedly decreased in the L-carnitine group as compared with the control (WMD = -2.48, 95% CI -4.35 to -0.61, P = 0.009), but showed no significant difference from the latter group after 24-26 weeks (WMD = -4.38, 95% CI -9.66 to 0.89, P = 0.1). No statistically significant difference was found in the semen volume between the two groups after 12-16 or 24-26 weeks of medication (WMD = -0.13, 95% CI -0.43 to 0.18, P = 0.42 and WMD = 0.28, 95% CI -0.02 to 0.58, P = 0.07). No serious L-carnitine-related adverse events were reported in 4 of the randomniized controlled trials.
  
  
  CONCLUSIONS
  The current evidence indicates that L-carnitine can improve spontaneous pregnancy and semen parameters in the treatment of idiopathic oligoasthenozoospermia, with no serious adverse reactions.
authors.forename: Xue-jun
authors.initials: XJ
authors.lastname: Shang
authors.forename: Ling-ling
authors.initials: LL
authors.lastname: Wang
authors.forename: Dun-sheng
authors.initials: DS
authors.lastname: Mo
authors.forename: Hong-cai
authors.initials: HC
authors.lastname: Cai
authors.forename: Da-dong
authors.initials: DD
authors.lastname: Zheng
authors.forename: Yuan-zhong
authors.initials: YZ
authors.lastname: Zhou
mesh_terms: D005260:Female; D006801:Humans; D008297:Male; D011247:Pregnancy; D053627:Asthenozoospermia / Q000188:drug therapy; D002331:Carnitine / Q000009:adverse effects / Q000494:pharmacology; D018873:Pregnancy Rate; D016032:Randomized Controlled Trials as Topic; D055101:Semen Analysis; D013076:Sperm Count; D013081:Sperm Motility
chemical_list: D002331:Carnitine