Congenital anomalies Flashcards
Outline the normal embryological development of the fallopian tubes, uterus, cervix and vagina
Müllerian ducts (paramesonephric duct) are formed as a pouch of parietal peritoneum adjacent to genital ridge, follow the line of the Wolffian duct. At week 5-6 these are indistinguishable from male tract.
Signalled by an absence of AMH from female gonads, from week 6 the two ducts fuse together – starting in the middle and move cranial and caudal. Fallopian tubes remain unfused and open to peritoneal cavity. Completed by 10th week. Wolffian duct regresses.
Lower aspect forms upper 1/3 of vagina. This fuses with the sinovaginal bulb of the urogential sinus to form hymen and distal 2/3 of vagina
Midline septum then absorbs to form single cavity – uterus, cervix, upper vagina complete by week 22.
What embryological abnormality causes uterus didelphys bicollis?
Failure of the Müllerian ducts (paramesonpehric) to fuse in the midline at 6-10weeks
A longitudinal vaginal septum is commonly associated with uterus didelphys bicollis, and is confirmed on pelvic examination in this patient. What symptoms might she describe that relate to this finding?
Difficulty with intercourse, dyspareunia
Difficulty or pain with tampon insertion
Persisting menses despite tampon insertion
Cyclical symptoms if septum obstructed - usually presents at menarche onset
May be asymptomatic
What additional investigations should you perform in a woman with uterine didelphys bicollis that are relevant to her long term health?
Cervical smears - ensure both sampled if possible
Renal tract imaging - USS or IVP, associated renal anomalies common (agenesis, pelvic kidney, horseshoe kidney)
Skeletal survey
What are late pregnancy complications associated with uterine didelphys bicollis?
PTB Malpresentation IUGR Labour dystocia CS PPH
Pre-pregnancy surgical options for uterine didelphys bicollis and vaginal septum and justification
- Resection of vaginal septum - to improve intercourse symptoms and reduce risk of labour dystocia
- Cervical cerclage - no benefit
- Strassman metroplasty - no benefit AND assoc morbidity
- Hemihysterectomy - no benefit AND assoc morbidity from vasculature disruption
- Laparoscopy +/- endo excision - to improve spontaneous pregnancy, only if significant retrograde menstruation and fertility delay
What is the differential diagnosis for ambiguous genitalia?
46XX virilisation – CAH, exposure to exogenous androgens (maternal androgen secreting tumor, danazol or testosterone use), placenta aromatase deficiency
46XY - Partial androgen insensitivity, androgen synthesis defect – 5-alpha-reductase deficiency, exposure to anti-androgens e.g. cyproterone
Mixed gonadal dysgenesis - Mosaic Turner’s
Ovotestis
What are investigations for ambiguous genitalia?
Confirm maternal Hx and medication use
Karyotype + SRY assessment
Electrolytes
17-OHP
ACTH stimulation test
LH, FSH – basal and GnRH stimualted
AMH
USS to assess if uterus and gonads present
Consider EUA
Laparoscopy and gonadal biopsy if uncertain
What is the definition of precocious puberty in girls?
Premature onset of menarche <9yo or secondary characteristics <8yo
What is the approximate incidence of precocious puberty in girls?
5%
What are two classifications and causes within each of precocious puberty?
Central = gonadotrophin dependent
- Idiopathic HPO axis maturation (most common, often FHx) - Tumour - Craniopharyngioma, SOL - Trauma - Hydrocephalus - Arachnoid cyst - Infection - meningitis, encephalitis - Irradiation - Hypothyroidism - Redundant GnRH tissue
Peripheral = gonadotrophin independent
- CAH and adrenal tumor - HCG secreting tumors - liver, adrenal, choriocarcinoma, ovarian - Ovarian tumor 2-5% - granulosa cell 60%, sertoli leydig - Functional ovarian cyst - Exogenous oestrogen - e.g. creams for adhesions - McCune Albright syndrome - Testotoxicosis genetic inheritance - Severe hypothyroidism - TSH stimulates LH and FSH receptors