Anogenital Distance and Penile Length in Infants with Hypospadias or Cryptorchidism:Comparison with Normative Data

Abstract

BACKGROUND: Anogenital distance (AGD) in animals is a sensitive biomarker of fetal endocrine disruption and the associated testicular dysgenesis syndrome (TDS). However, AGD in human infants with cryptorchidism and hypospadias, which are potential manifestations of TDS during childhood, is not clearly described. OBJECTIVE: Our aim was to compare AGD in boys with cryptorchidism or hypospadias against normative data. METHODS: Boys with isolated cryptorchidism (n = 71, age 13.4 ± 5.8 months) or hypospadias (n = 81, age 11.4 ± 6.2 months) were recruited from a tertiary center for measurement of AGD and penile length; they were compared with 487 healthy full-term boys from a birth cohort by deriving age-specific standard deviation scores (SDS). RESULTS: Boys with cryptorchidism were older (p = 0.048) compared with boys with hypospadias. Boys with hypospadias had shorter mean AGD and penile length SDS than healthy boys (both p < 0.0001). Mean AGD and penile length SDS values in boys with cryptorchidism were longer than mean values in boys with hypospadias (both p < 0.01) and shorter than mean values in healthy boys (both p < 0.0001). Mean penile length SDS decreased as the severity of hypospadias increased (ptrend = 0.078). CONCLUSIONS: In the study population, AGD and penile length were reduced in boys with hypospadias or cryptorchidism relative to normative data derived from a longitudinal birth cohort. The findings support the use of AGD as a quantitative biomarker to examine the prenatal effects of exposure to endocrine disruptors on the development of the male reproductive tract.