IntrOductIOnBenign prostatic hyperplasia (BPH) is the most common prostate disease, characterized by nonmalignant enlargement of the prostate gland in aging men. It is a major health issue among elderly men. BPH increases markedly after the 4 th decade of life. Its incidence increases to 90% in men over 80 years [1]. Although the exact pathogenesis of BPH is not completely understood, aging, testosterone levels, lower urinary tract infections, inflammation, alteration in cell signaling are considered significant risk factors for the development of BPH [2]. Of these factors, testosterone is said to be the major factor since it is known to play an important role in growth of prostate gland. The effects of several growth factors involved in the development of BPH like fibroblast growth factors (FGFs), vascular endothelial growth factors (VEGFs), and insulin like growth factors (IGFs) are modulated by dihydrotestosterone (DHT), a derivative of testosterone [3].The relative length of 2 nd and 4 th digit is a marker for prenatal androgen exposure. A low 2D:4D ratio is associated with a high prenatal androgen exposure. Since there are practical difficulties in measurement of testosterone exposure in the fetus, researchers have adopted a non-invasive method in the form of measurement of 2D:4D ratio, a widely accepted retrospective biomarker for prenatal androgen exposure [4]. It has been shown that alterations in digit ratio (2D:4D) is associated with a wide range of physiological & psychological characteristics like alcoholism [5], attention deficit disorder [6], visuo-spatial ability [7], susceptibility to coronary artery disease [8], assertiveness and aggression [9], homosexuality [10] and depression [11]. It is also found to be linked with prostatic cancer [12].Testosterone is implicated in the development of prostate gland as it promotes prostate cell proliferation [13]. DHT is found to be a critical mediator of prostatic growth [14]. However, relatively low levels of serum testosterone are found in patients with BPH [15]. Exposure to varying levels of androgens in fetal life is found to affect several attributes of masculinity in males. This may also be true with respect to the growth of prostate in adult life and its subsequent hyperplasia in old age. Studies have not been conducted till date to determine the effect of prenatal androgen exposure on the growth of prostate gland and BPH. The present study is an indirect measure of prenatal testosterone exposure and its relation to development of BPH. The main objective of the present study was to assess the causal relationship between the 2D:4D ratio and incidence of BPH. MAterIAls And MethOdsThe present study recruiting 105 participants was conducted between June 2013 and February 2014 in the Department of Urology, Kempegowda Institute of Medical Sciences Hospital and Research Centre, Bangalore. They were divided into three groups -BPH, non BPH and controls with 35 participants in each group. Written informed consent was obtained from all the study subjects/ legal...