Congenital anomalies

Question 1

Outline the normal embryological development of the fallopian tubes, uterus, cervix and vagina

Answer 1

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.

Question 2

What embryological abnormality causes uterus didelphys bicollis?

Answer 2

Failure of the Müllerian ducts (paramesonpehric) to fuse in the midline at 6-10weeks

Question 3

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?

Answer 3

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

Question 4

What additional investigations should you perform in a woman with uterine didelphys bicollis that are relevant to her long term health?

Answer 4

Cervical smears - ensure both sampled if possible
Renal tract imaging - USS or IVP, associated renal anomalies common (agenesis, pelvic kidney, horseshoe kidney)
Skeletal survey

Question 5

What are late pregnancy complications associated with uterine didelphys bicollis?

Answer 5

PTB
Malpresentation
IUGR
Labour dystocia
CS
PPH

Question 6

Pre-pregnancy surgical options for uterine didelphys bicollis and vaginal septum and justification

Answer 6

1. Resection of vaginal septum - to improve intercourse symptoms and reduce risk of labour dystocia
2. Cervical cerclage - no benefit
3. Strassman metroplasty - no benefit AND assoc morbidity
4. Hemihysterectomy - no benefit AND assoc morbidity from vasculature disruption
5. Laparoscopy +/- endo excision - to improve spontaneous pregnancy, only if significant retrograde menstruation and fertility delay

Question 7

What is the differential diagnosis for ambiguous genitalia?

Answer 7

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

Question 8

What are investigations for ambiguous genitalia?

Answer 8

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

Question 9

What is the definition of precocious puberty in girls?

Answer 9

Premature onset of menarche <9yo or secondary characteristics <8yo

Question 10

What is the approximate incidence of precocious puberty in girls?

Answer 10

5%

Question 11

What are two classifications and causes within each of precocious puberty?

Answer 11

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