Definition of Clitoromegaly
Clitoromegaly is defined as abnormal enlargement of the clitoris, with a clitoral length exceeding 6.5 mm (95th percentile) in neonates, and values ≥8 mm warranting further investigation. 1
Anatomical Measurement Standards
- In full-term and preterm female neonates, the mean clitoral length at day 3 of life is 3.69±1.53 mm, with a maximum normal measurement of 6.5 mm at the 95th percentile 1
- Clitoral size does not vary significantly with gestational age or birth weight, so clitoromegaly should not be attributed to prematurity 1
- In non-erect adult females, the clitoris typically has a diameter of no more than 0.5 cm 2
- The anogenital ratio >0.6 should be considered a sign of virilization in neonates 1
Clinical Classification
The condition is characterized by severity using the Prader scale, though this is most commonly applied to assess genitalia in disorders of sex differentiation (DSD) 2. The guidelines distinguish between:
- Moderate clitoromegaly: May regress with medical therapy, particularly in congenital adrenal hyperplasia (CAH) 3
- Severe clitoromegaly: Consensus recommendations support clitoroplasty in these cases 3
Etiology Categories
Clitoromegaly can be either congenital or acquired 4, 5:
Congenital Forms
- Usually caused by hormonal disturbances or intersex states 5
- Typically obvious at birth 5
- Most commonly due to excess androgens in fetal life 4
Acquired Forms
- Hormonal causes: Androgen excess from endocrinopathies, masculinizing tumors, or synthetic androgen use 5
- Non-hormonal causes: Neurofibromatosis, epidermal inclusion cysts, or sebaceous cysts 5, 6
- Idiopathic: When no underlying etiology is identified despite comprehensive evaluation 2
Important Clinical Caveat
When clitoromegaly develops after the neonatal period, the underlying etiology must be thoroughly explored, as acquired causes require different management approaches than congenital conditions 5. In extremely premature infants, transient clitoromegaly may occur due to temporarily elevated androgens of ovarian and adrenal origin, which typically resolves spontaneously 7.