Definition

• New nomenclature: disorders of sexual development (DSD) known formerly as ambiguous genitalia
• Congenital conditions in which development of chromosomal, gonadal or anatomical sex is atypical, most commonly:
  
  • congenital adrenal hyperplasia
  • gonadal dysgenesis
  • partial androgen insensitivity
• For DSD classification, see Supporting information

Factors suggesting DSD

• Overt genital ambiguity (e.g. cloacal extrophy)
• Apparent female genitalia with enlarged clitoris, posterior labial fusion or inguinal/labial masses
• Apparent male genitalia with bilateral undescended testes, isolated perineal hypospadias, micropenis (normal penis ≥1.9 cm), or mild hypospadias with undescended testis
• Family history of DSD e.g. complete androgen insensitivity syndrome (CAIS)
• Discordance between genital appearance and antenatal karyotype
• Pseudo-ambiguity (atrophic vulva and clitoral oedema) in growth-restricted or preterm female babies

• Avoid gender assignment before expert evaluation
• Consultant to discuss with parents
  
  • always use the term ‘baby’ and avoid using ‘he’, ‘she’ or, most importantly, ‘it’
  • advise parents about delaying registration and informing wider family and friends until gender assignment complete
  • liaise with laboratory to enable evaluation without indicating gender in laboratory request forms
• Link with expert centre for appropriate evaluation
• Communicate openly with family
• Respect family concerns and culture
• DSD is not shameful
  
  • best course of action may not be clear initially
  • parents need time to understand sexual development

First line investigations

• Blood pressure
• Karyotype of QF-PCR (urgent)
• Imaging
  
  • abdominal and pelvic ultrasound by an experienced paediatric sonographer 
  • assess presence and nature of internal genitalia, including gonads
• Blood tests
  
  • cortisol short synacthen test
  • 17-OHP (delay until day 3 to allow maternal hormonal effects to decline)
  • testosterone and oestradiol
  • LH, FSH
  • U&E and glucose

Further investigations (following discussion with specialist endocrine advice)

• dHT (dihydrotestosterone)
• DHEA (dihydroepiandrosterone)
• Androstenedione 
• ACTH
• LHRH and hCG stimulation 
• ACTH stimulation test
• AMH (anti-mullerian hormone) imaging studies
• Molecular genetic studies [e.g. for complete androgen insensitivity syndrome (CAIS)]
• Urine: steroid profile
• Biopsy of gonad

• Avoid unnecessary admission to NNU
• Check serum electrolytes and plasma glucose 
  
  • in congenital adrenal hyperplasia electrolytes usually not abnormal until day 4
• Involves a multidisciplinary team with an identified person (usually consultant neonatologist) acting as primary contact with family
• Specific treatment dependent on many factors and diagnosis
  
  • discuss with specialists