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Updated: Jun 6, 2026
Anogenital Distance and Perineal Measurements of the Pelvic Organ Prolapse (POP) Quantification System
Published on: September 20, 2018
Reference values for Japanese fetal penile length
Toshiyuki Hata1,2, Yume Takahashi3, Miyu Konishi3
1Department of Obstetrics and Gynecology, Miyake Clinic, 369-8 Ofuku, Minami-Ku, Okayama, 701-0204, Japan. hata.toshiyuki@kagawa-u.ac.jp.
Purpose:
To determine reference values for Japanese fetal penile length using ultrasonography at 18-21 + 6 as well as 28-31 + 5 weeks of gestation.
Methods:
Three hundred and five pregnant women were enrolled in the study, and fetal penile length was measured at both 18-21 + 6 and 28-31 + 5 weeks of gestation. All 305 fetuses were successfully measured. Outer penile length (OPL) of the male fetus was measured, and OPL reference values were determined. Intra- and inter-observer agreements regarding OPL were also assessed with Bland-Altman plots and intra- and inter-correlation coefficients.
Results:
OPL showed an increasing trend with advancing gestation at 18-21 + 6 (r = 0.2757, p < 0.001) and 28-31 + 5 (r = 0.2306, p < 0.001) weeks. Intra- and inter-reproducibilities of OPL were excellent. Intra- and inter-correlation coefficients of OPL were 0.982287 and 0.885602, respectively, at 18-21 + 6 weeks, and 0.994104 and 0.97343, respectively, at 28-31 + 5 weeks.
Conclusion:
Our results provide reference values for Japanese fetal penile length, which may promote accurate prenatal diagnoses of hypospadias, micropenis, and buried penis in Japan.
