Penile length of newborns in Singapore.

Micropenis is an important sign in congenital hypopituitarism and various disorders. Documented norms for penile length exist only for babies of Caucasian and Middle-Eastern origin. This study was carried out to establish such norms for Asian newborns. We studied 228 male live births within their first three days of life. Stretched penile lengths were marked off on unmarked wooden spatulas, which were placed vertically along the dorsal aspect of the penis, with one rounded end on the pubic bone. The mean penile length +/- S.D. for the full-term Asian baby was 3.6 +/- 0.4 cm. Race had a significant effect: Chinese 3.5 cm, Malay 3.6 cm and Indian 3.8 cm. Penile length correlated with birth weight and gestational age. Asian babies thus have similar norms to Caucasian babies. An Asian newborn whose penis measures less than 2.6 cm has micropenis and may need prompt investigation for underlying endocrine disorders.