Sperm counts and sperm sex ratio in male infertility patients

摘要

In recent years,investigators have noted a trend toward a declining proportion of male births in many industrialized nations.While men bear the sex-determining chromosome,the role of the female partner as it pertains to fertilization or miscarriage may also alter the gender ratio.We attempted to determine a man's secondary sex ratio (F1 generation) by directly examining the sex chromosomes of his sperm.We examined our male infertility clinic database for all men who had undergone a semen fluorescence in situ hybridization (FISH).Patient demographic and semen parameters were recorded.Chi-squared analysis was used to compare gender ratios (Ychromosomes/total chromosomes).Multivariable logistic regression was used to predict the odds of possessing a Y-bearing sperm after accounting for demographic and semen parameters.A total of 185 men underwent sperm FISH.For the entire cohort,the proportion of Y chromosome-bearing sperm was 51.5％.Men with less than five million motile sperm had a significantly lower proportion of Y chromosome-bearing sperm (50.8％) compared to men with higher sperm counts (51.6％; P=0.02).After multivariable adjustment,a higher sperm concentration,total motile sperm count and semen volume significantly increased the odds of having a Y chromosome-bearing sperm (P＜0.01).As a man's sperm production declines,so does the proportion of Y chromosome-bearing sperm.Thus,a man's reproductive potential may predict his ability to sire male offspring.