Stretched penile length and total serum testosterone in term male neonates

Abstract

Introduction the reference values of stretched penile length vary with different ethnic group. There is paucity of data on the reference range of total serum testosterone in neonates especially in Africa. This study therefore was to determine the normal stretched penile length, total serum testosterone levels in term male newborns and to correlate them with anthropometric parameters. Methods this was a prospective cross-sectional study. One hundred and twenty-four consecutive healthy term male neonates were recruited in the first 72 hours of postnatal life. The stretched penile length (SPL) was measured with a rigid metric ruler. Weight, length and occipitofrontal circumference were also measured. Total serum testosterone level was determined using Enzyme Linked Immunoassay. Data were analysed using the Statistical Package for Social Sciences for Windows version 20. Results a total of 124 term male neonates were recruited. The postnatal age of recruited neonates was one to 70 hours with a mean of 22.8 ± 17.6 hours and the mean of estimated gestation age was 38.5 ± 1.3 weeks. The range of stretched penile length was from 2.1 to 3.9 cm with a mean of 3.2 ± 0.4 cm and SPL less than 2.2 cm was considered as micropenis. The mean total serum testosterone level was 357.4 ± 241.7 ng/dl. The SPL had a positive correlation with the birth weight, length and total serum testosterone. The total serum testosterone and birth length were predictors of stretched penile length. Conclusion among the studied population the mean stretched penile length was 3.2 cm and mean total serum testosterone was 357.4 ng/dL.

Penile size in term newborns in Addis Ababa, Ethiopia

“…6 In the current study, our finding of mean SPL as 3.28 ± 0.42 cm for all gestational age is closely similar with the mean SPL of babies from other African countries (Table 3). [11][12][13]18,19 On the other hand, our finding is lower than an earliest publication on penile standards for American newborns by Feldman et al which reported a larger (3.5 ± 0.7 cm) penile length for full-term infants. 8 Studies that employed a similar methodology reported different penile sizes for Asian population as it was summarised in Table 3.…”

Anthropometric Predictors of Appropriate-Sized Plastibell for Neonatal Circumcision

“…The implication of this is that irrespective of age, most penile glans has about same size. This is explained by the fact that penile size is about a constant in infancy due to a steady state of serum testosterone required for penile growth ( 14 , 15 ). It becomes a disincentive for using age to determine the appropriate size of Plastibell in neonates.…”

Society for Endocrinology UK Guidance on the initial evaluation of a suspected difference or disorder of sex development (Revised 2021)

“…In newborn girls, the length of the clitoris does not seem to be dependent on gestation and a newborn with a length greater than 8mm requires further evaluation 40 . Micropenis is defined as a stretched penile length of less than 2.5SD from the mean and based on contemporary studies from a wide range of countries, a stretched penile length of less than 2cm would represent a reasonable cut off for micropenis in the newborn 34,41–45 . In approximately 25% of affected cases, XY DSD is part of a complex multi‐system condition 37,46 and the coexistence of a systemic metabolic disorder, other associated conditions or dysmorphic features would lower the threshold for investigation as would a family history of consanguinity, stillbirths, multiple miscarriages, fertility problems, genital abnormalities, hernias, delayed puberty, genital surgery, unexplained deaths and the need for steroid replacement.…”