Disorders of sexual development (DSD)

Most common DSD if karyotype is XY (male)

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  Hypospadias: Urethra opens on underside of penis

  
  
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  Epispadias (less common): Urethra opens on top of penis

  
  
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  Cryptorchidism: Empty, small scrotum

  
  
  
  
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    Often with small or abnormal penis

  
  

Most common DSD if karyotype is XX (female)

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  Clitoromegaly ± congenital adrenal hyperplasia (CAH)

  
  
  
  
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    CAH causes virilization

  
  
  
  
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  Prominent or fused labia (less common)

Hypospadias

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  Penis ends bluntly instead of normal taper

  
  
  
  
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    Lateral echogenic lines at tip = prepuce folds

  
  
  
  
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  Penis may be small and curved upward (chordee)

  
  
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  Tulip sign: Small, curved penis between scrotal folds

Epispadias: Small, bifid penis

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  Associated with bladder extrophy

Clitoromegaly (mimics small penis)

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  Associated prominent or fused labia mimic scrotum

  
  
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  CAD association: Adrenal glands may be large or normal

Sex of fetus from genetic testing is key to diagnosis

Some aspect of DSD seen in 1-2% of all live births

Hypospadias in 1:200-250 males

CAH is autosomal recessive (25% recurrence risk)

Aneuploidy association: Trisomy 13, triploidy, trisomy 18

Associated anomalies in 1/2 (most upper urinary tract)

Do not assign sex at time of scan when DSD is suspected

Pay attention to morphology of tip of phallus

Look for testes in scrotum after 25 weeks

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  97% descended by 32 weeks