Study Of The Penile Growth Of Normal Males

Objective: Penis size is an important measure of male sexual development whose development may affect sexual function and fertility. Early and delayed development of the penis will lead to quite difference of penis size at the same age especially in puberty. In order to accurately judge whether it is normal on penis size and growth, penis size of the patient must be accurately measured at first, then we will make reasonable judgments comparing with the size and growth pattern of normal penis. Now there have been measure reports about normal penis size, but in domestic data theses sample quantities are few, or dividing group is not reasonable, or scope of referencing to group is too limited to provide use for the clinical reference . In oder to obtain the size and growth pattern of normal penis which can provide use for the clinical reference and be applied to discuss the growth relationship between penis and testicle , we performed the measure of the penis size in chinese normal male, including all ages from newborn to adult.Methods: The measured groups were mainly from outpatients without penis disease. The penile length, diameter of penis coronal and testicular volume were measured directly. In order to be referenced conveniently, each age varying from 0 to 18 years was divided into a group coupled with the newborn infants and adult group.Results: A total of 2187 normal male subjects were from southern and western areas , most of them were the Han nationality ,about 20% were minority peoples. They were divided into 21 groups. According to the statistical results, firstly the normal reference value on penis size and testicular volume of each age were obtained. Secondly the growth of normal penis was approved : the growth rate of penis length of subjects less than 1 year was relatively fast (P<0.01), which was slow in 1~11 year old group, and compared with the adjacent group, there was no significant difference (P>0.05). 11~15 years old ones got into the period of rapid growth. It exhibited highly significant interobserver variation (P<0.01). Over 15 years old, penile size was increasing with age, but significant difference was not noted. There was a positive correlation between penile length and age (r=0.449,p=0.0). Thirdly Over 11 years old ,diameter of penis coronal had a more rapid growth and got synchronous increase with penis length. There was a positive correlation between diameter of penis coronal and age (r=0.591,p=0.0). Fourthly testicular growth was as follows: it was about one year earlier than the penis. the growth rate of testicular volume of subjects less than 1 year was fast (P<0.05), which was slow in 1~9 year old group, and compared with the adjacent group, there was no significant difference (P>0.05). 9~15 years old ones got into the period of rapid growth. It exhibited highly significant interobserver variation (P<0.01). Over 15 years old, testicular volume was increasing with age, but significant difference was not noted. There was a positive correlation between tsticular volume and age (r=0.487,p=0.0). Testicular growth was similar to penis, but the growth was one year earlier than the penis. Fifth there was a positive correlation between tsticular volume and penis length (r=0.797,p=0.0).Conclusions: The study involve a wide and extensive population. The direct measurements are simple and reliable. And These data are in accordance with the pattern of Chinese male penile growth. The results provide the reference of domestic penile growth which can be consulted in the clinical diagnosis.