Testing clitoris and penis length in Nigeria to establish “normality”

The peer-reviewed article “Clitoral and penile sizes in healthy newborn babies in Ibadan, Nigeria” reports on a study by three researchers, one each from Ibidan, Nigeria; Stockholm, Sweden; and Manchester, England, who set out to measure the length and circumference of the genitalia of 515 newborn Nigerian infants. The rationale for this undertaking was to establish normal size ranges for penises and clitorises in Nigeria and compare the information with that of other “races” in other countries.

The justification is that establishing ‘normal’ genital ranges is a useful way of detecting otherwise unrecognized genital abnormalities.

OII believes that these measurements and comparisons are used to set the standards for intersex genital normalization surgeries in those countries which practice this form of non-consensual infant genital surgery.

We reject the need to determine the correctness of human genitalia based on non-functional issues.


Standards of penile and clitoral lengths are useful for diagnosis of genital abnormalities. Micropenis could be the only sign in pituitary/hypothalamic dysfunction while clitoromegaly may reflect abnormalities of neonatal and maternal origin. Ambiguous genitalia if missed at birth could be fatal especially in cases of congenital adrenal hyperplasia. There are no African reports on normal reference ranges of both penile and clitoral sizes. This study aimed to generate key information that did not exist on the size of external genitalia of newborn babies in Nigeria.


To establish the normal reference values for penile and clitoral sizes in Nigerian infants and to compare with standards from other ethnic populations.


A total number of 515 healthy newborn babies delivered at gestational ages 28 weeks or more were enrolled in the study. Clitoral or penile lengths and widths were taken less than 72 h after birth in all of them.

Results: The mean penile length in the 264 Nigerian males studied was 3.4±0.49 cm while the mean width was 1.2±0.17 cm. Nigerian newborn had similar penile sizes as the Caucasians (3.4±0.3 cm); larger than the Chinese (3.1±0.4 cm) but significantly smaller than those of Indian (3.6±0.4 cm), Turkish and Malaysian origin. The mean clitoral length in the 251 Nigerian females studied was 7.5±1.8 mm while the mean clitoral width was 4.4±0.89 mm. The clitoral sizes were significantly larger than those in the Caucasian (4±1.24 mm), Korean and Japanese babies.


The overall figures in Nigerian newborns deferred from values obtained from other countries. There were significant variations in clitoral and penile sizes between different ethnic populations. The measurement of genital sizes should be part of routine newborn physical examination.

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