The ratio of 2nd to 4th digit length and reproductive function of infertile male patients

Abstract

Abstract Purpose To investigate the relationship between the ratio of index to ring finger lengths (2D:4D ratio), reflecting androgen exposure in utero, and reproductive function among men. Methods Male patients (N = 180) who consulted for fertility issues participated in the study. The palms of both hands were scanned, and the 2D:4D ratio was calculated. Data on semen volume, sperm concentration and total motility, total and motile sperm counts, and serum hormone concentrations were obtained. Spearman correlation coefficients between the 2D:4D ratio and hormone and semen quality parameters were calculated. Results The total sperm count was significantly negatively correlated with the 2D:4D ratio of the left hand (r = −0.154, p = 0.039) but not with that of the right hand (r = −0.045, p = 0.548). Testosterone showed weak negative correlations with the 2D:4D ratio in the left (r = −0.142, p = 0.058) and right (r = − 0.149, p = 0.046) hands. Follicle‐stimulating hormone levels were negatively correlated with the 2D:4D ratios of the left (r = −0.173, p = 0.020) and right (r = −0.164, p = 0.027) hands. Other semen quality parameters or luteinizing hormone levels showed no significant correlation with the 2D:4D ratios. Conclusions No clear associations were observed between the 2D:4D ratios and reproductive function.

Keywords

• androgens
• digit ratio
• hormone
• male infertility
• semen quality