Body Mass Index In Relation To Sperm Count:An Systematic Review And Meta-analysis

ObjectiveThis study aims to assess the association between BMI and sperm count through a systematic review with meta-analysis.MethodsA system review of available literature was performed to investigate the impact of BMI on spermcount. Relevant studies published until December 2015 were identified from a Pubmed and EMBASE search.ResultsA total of 23 studies were include in the meta-analysis, resulting in a sample of 13694 men from the general population and attending fertility clinics. Data were stratified according to the total sperm count as normozoospermia, oligozoospermia and azoospermia. Standardized weighted mean difference in sperm concentration did not differ significantly across BMI categories. There was a J-shaped relationship between BMI categories and risk for abnormal sperm count. Compared with men of normal weight, the odds ratio(95%CI) for abnormal sperm count was 1.15(0.93-1.43) for underweight,1.12(1.02-1.22) for overweight,1.32(1.10-1.59) for obese and 2.09(1.62-2.70) for morbidly obese men.ConclusionOverweight and obesity were associated with an increased prevalence of azoospermia or oligozoospermia. There is no significant association between underweight and abnormal sperm count. Whether weight loss could improve sperm parameters should be evaluate further.