Stretched penile length at birth: a systematic review

Area of Science:

• Endocrinology
• Pediatrics
• Neonatology

Background:

• Micropenis is diagnosed at birth using stretched penile length (SPL), a method established 80 years ago.
• Recent studies show discrepancies in normative data, necessitating a methodology revision.
• Current diagnostic criteria may not accurately reflect current populations.

Purpose of the Study:

• To compare normative data for SPL at birth.
• To examine the methodology of SPL measurement.
• To evaluate independent variables influencing SPL.

Main Methods:

• Systematic review of MEDLINE, EMBASE, Scielo, Cochrane Library, and Web of Science.
• Included normative studies of healthy, full-term newborns (first month of life).
• Analyzed study characteristics, methodology, and independent variables.

Main Results:

• 49 studies and 21,399 children were analyzed.
• Significant discrepancies exist between normative SPL data.
• Ethnic group and gestational age were key independent variables.
• Methodological aspects were largely consistent.

Conclusions:

• Existing normative data for stretched penile length (SPL) show significant discrepancies.
• Ethnic group and gestational age influence SPL.
• Developing customized reference charts for specific populations is recommended over universal cut-offs.