Disorders of sexual development Flashcards
Describe the embryology of the uterus and the vagina
Begins at 3/40 until trimester 2
Derived from the mullerian ducts, urogenital sinus & vaginal plate
closely associated with development of the urinary system
the internal female reproductive tract (tubes, uterus, upper 1/3 of vagina) is formed from the fusion of the mullerian ducts when there is an absence of AMH
What are the 3 categories of Mullerian duct abnormalities?
- lateral fusion abnormalities
- vertical fusion abnormalities
- agenesis
Give 4 examples of lateral fusion abnormalities of the mullerian duct?
Septate/arcuate
Bicornuate
Unicornuate
Uterine didelphys
What is a septate uterus?
- uterus appears as a single organ but has a midline septum that is either partial or complete
- arcuate uterus has only a small septate indentation present
What is a bicornuate uterus?
Single chamber vagina and cervix with complete or partial septate uterus and two uterine bodies
what is a uni-cornuate uterus?
When there is destruction of one of the mullerian ducts during the embryonic period, this abnormality is often associated with a missing kidney or uterer on ipsilateral side
What is uterine didelphys?
Complete duplication of the vagina, cervix and uterus
Give 4 examples of vertical fusion abnormalities of the mullerian duct
- transverse vaginal septum
- absent cervix
- cervical stenosis
- cervical incompetence
What are the obstetric implications of mullerian duct abnormalities?
- fertility issues - (agenesis = cannot get pregnant)
- miscarriage - increased risk, resection of septum may improve pregnancy rates
- increased risk of APH
- malpresentation
- increased risk of CS due to incoordinate contractions
What determines the male phenotype?
SRY gene on Y c’some makes SRY protein which stimulates germ cells and testes to form
Presence of testosterone (from leydig cells) stimulates the Wolffian duct development (vas deferens, epididymis, seminal vesicles)
Presence of AMH (from Sertoli cells) prevent Mullerian duct development
Testosterone is converted to DHT by alpha reductase
DHT stimulates the male external genitalia via androgen receptor
What determines female phenotype?
Lack of Y chromosome means DAX-1 stimulates gonads to become ovaries
Lack of AMH means that mullerian duct develops
Lack of testosterone results in regression of Wolffian duct
Lack of testosterone, DHT, alpha reductase means the external female genitalia form
What are the 5 conditions associated with Karyotype XY but female phenotype?
- androgen insensitivity syndrome
- 5alpha reductase deficiency
- true gonadal dysgenesis (swyer syndrome)
- AMH deficiency
- Abnormal androgen synthesis
What are the 5 main management steps for a XY karyotype, female phenotype?
- MDT input, tertiary centre
- psychologica support
- physical development and maintenance - estrogen replacement
- removal of gonads
- Fertility
What are the symptoms someone with uterine didelphyis might present with?
- outlet obstruction
- tampon failure
- sexual dysfunction
- possible reduced fertility if obstructing
What extra investigations does someone need once uterine didelphys diagnosed?
- renal USS
- dual smears
