development of female genitalia

What are the two genital ducts present in both male and female fetuses during IUL?

Müllerian (paramesonephric) duct and Wolffian (mesonephric) duct.

What is the origin of the Müllerian duct?

Invagination of coelomic epithelium.

What is the origin of the Wolffian duct?

Intermediate mesoderm.

What does the Müllerian duct form?

Female internal genitalia.

What does the Wolffian duct form?

Male internal genitalia.

Which duct develops first: Müllerian or Wolffian?

Wolffian duct.

What is the role of the Wolffian duct in Müllerian development?

It acts as a template for Müllerian duct formation.

Failure of Wolffian duct growth is associated with what Müllerian abnormality?

Absent Müllerian duct.

What important association should be ruled out with Müllerian anomalies?

Renal anomalies.

What does the Müllerian duct carry along bilaterally?

A fold/sheath of coelomic epithelium.

What does this fold/sheath of coelomic epithelium form?

Broad ligament.

At what gestational age does the Müllerian duct form the female internal genital organs?

~9 weeks IUL.

At what gestational age does the Wolffian duct regress in females?

~10 weeks IUL.

What are the main remnants of the Wolffian duct in females?

Epoophoron, paroophoron and Gartner's duct.

Where are Wolffian duct remnants located?

Broad ligament.

What is the epoophoron?

Cranial remnant of mesonephric tubules.

What is the paroophoron?

Caudal remnant of mesonephric tubules.

What is Gartner's duct?

Remnant of the mesonephric duct.

Where is a Gartner's cyst typically located?

Anterolateral wall of the vagina.

How does a Gartner's cyst typically present?

As a vaginal swelling; may be asymptomatic, cause difficult intercourse or a feeling of something coming out of the vagina.

What are the important differentials of a Gartner's cyst?

Bartholin cyst and cystocele.

How is a Gartner's cyst distinguished from a cystocele clinically?

Gartner cyst: non-reducible, absent rugae and absent cough impulse. Cystocele: reducible, rugae present and cough impulse present.

What is the management of an asymptomatic Gartner's cyst?

No intervention.

What is the management of a symptomatic Gartner's cyst?

Removal/excision of the cyst.

What structures constitute the female internal genitalia?

Fallopian tubes, uterus, cervix and vagina.

What does each Müllerian duct form?

One fallopian tube, half of uterus, half of cervix and upper 1/3 of vagina.

How do the two Müllerian ducts fuse?

They initially lie lateral to the Wolffian ducts and then cross the Wolffian ducts to meet in the midline.

In what direction does Müllerian duct fusion occur?

From below upwards.

By when is complete Müllerian duct fusion normally complete?

~10 weeks IUL.

By when does the uterine septum normally resolve?

~18–20 weeks IUL (5th month).

By when does the endometrium differentiate?

~20 weeks IUL.

What is the origin of the ovaries?

Genital ridge.

What is the origin of the lower 2/3 of the vagina?

Urogenital sinus.

Which structures are unaffected in Müllerian malformations?

Ovaries and lower 2/3 of vagina.

What is the basic defect in Müllerian malformations?

Abnormal formation and/or fusion of Müllerian ducts.

What is the most common Müllerian anomaly?

Septate uterus.

What is the most common presentation of Müllerian anomalies?

Recurrent abortions.

Which Müllerian anomaly has the best reproductive outcome?

Arcuate uterus.

Which Müllerian anomaly has the worst reproductive outcome?

Septate uterus.

Which Müllerian anomaly is most commonly associated with renal anomalies?

Unicornuate uterus.

Which Müllerian anomalies are associated with unilateral renal agenesis?

Unicornuate uterus and obstructed hemivagina.

What is Class I Müllerian anomaly?

Bilateral absence of Müllerian ducts → Müllerian agenesis.

What structures are absent in Müllerian agenesis?

Fallopian tubes, uterus, cervix and upper 1/3 of vagina.

Are ovaries and ovulation normal in Müllerian agenesis?

Yes.

What is Class II Müllerian anomaly?

Unicornuate uterus due to one Müllerian duct being present.

What structures are present in a unicornuate uterus?

One fallopian tube, 1/2 uterus, 1/2 cervix and 1/2 upper 1/3 vagina.

What types of rudimentary horn can occur with a unicornuate uterus?

Communicating or non-communicating rudimentary horn.

What are important features associated with a unicornuate uterus?

Unilateral dysmenorrhea, ectopic pregnancy, ectopic ovary and unilateral renal anomalies.

What is the typical HSG appearance of a unicornuate uterus?

Single-sided spill with a banana-shaped uterus.

What cannula may be required on HSG for a unicornuate uterus?

Leech-Wilkinson cannula.

What is Class III Müllerian anomaly?

Uterus didelphys.

What causes uterus didelphys?

Bilateral Müllerian ducts fail to fuse, or fuse only in the region of the vagina.

What is the anatomy of uterus didelphys?

Two fallopian tubes, two uterine halves, two cervices and two vaginas OR a single vagina.

What is a longitudinal vaginal septum associated with?

Uterus didelphys.

What can an obstructed hemivagina cause?

Hematocolpos and dysmenorrhea/pelvic mass.

What renal anomaly is associated with obstructed hemivagina?

Ipsilateral renal agenesis.

What is Class IV Müllerian anomaly?

Bicornuate uterus.

What is the anatomy of a bicornuate uterus?

Two fallopian tubes, two uterine cavities/horns, one cervix and one vagina.

What is the key external feature of a bicornuate uterus?

Divided/cleft fundus.

What is Class V Müllerian anomaly?

Septate uterus.

What causes a septate uterus?

Both Müllerian ducts fuse, but the intervening septum fails to resolve.

What is the key external appearance of a septate uterus?

Externally normal uterus with an internal septum.

What is the fundal appearance in septate uterus?

Fundus is not divided.

What is Class VI Müllerian anomaly?

Arcuate uterus.

What is an arcuate uterus?

Mildest Müllerian anomaly with a mildly indented/flat-topped fundus.

What is the reproductive outcome of arcuate uterus?

Best reproductive outcome.

What is Class VII Müllerian anomaly?

In-utero exposure to diethylstilbestrol (DES).

What is DES?

Synthetic estrogen previously given to females, including for prevention of abortions.

What is the most common vaginal defect associated with in-utero DES exposure?

Vaginal adenosis.

What is vaginal adenosis?

Areas of vagina lined by columnar epithelium.

What is the most common cancer associated with DES exposure?

Clear cell carcinoma.

What cervical abnormalities can DES exposure cause?

Cervical hoods/collars.

What is the most common uterine finding after DES exposure?

Hypoplastic uterus.

What is the most specific uterine finding after DES exposure?

T-shaped uterus.

What are chronic reproductive outcomes of DES exposure?

Increased risk of breast cancer and increased chances of premature menopause.

Are renal anomalies typically associated with DES exposure?

No.

What are important abnormalities in male fetuses exposed to DES?

Cryptorchidism, testicular hypoplasia, hypospadias, microphallus and renal anomalies.

How can bicornuate and septate uterus be differentiated by the fundus?

Bicornuate: fundus divided/externally indented. Septate: fundus externally normal.

Can HSG reliably differentiate bicornuate from septate uterus?

No.

On HSG, what angle between the two horns favors bicornuate uterus?

Obtuse angle >105°.

On HSG, what angle between the two horns favors septate uterus?

Acute angle <75°.

On HSG, what inter-horn distance favors bicornuate uterus?

4 cm.

On HSG, what inter-horn distance favors septate uterus?

What is the most common Müllerian anomaly?

Septate uterus.

What is the most common Müllerian anomaly associated with recurrent abortions?

Septate uterus.

What is the most common anomaly associated with ectopic pregnancy?

Unicornuate uterus.

Which Müllerian anomaly is associated with preterm labour?

Bicornuate uterus.

Why does preterm labour occur with Müllerian anomalies?

Altered shape/capacity of the uterus.

Which Müllerian anomalies are associated with malpresentation?

Especially uterus didelphys, septate uterus and bicornuate uterus.

What is the most common presentation of malpresentation in Müllerian anomalies?

Breech presentation.

What is the most common cause of recurrent breech presentation?

Müllerian malformations.

Which anomalies are associated with transverse lie?

Septate and bicornuate uterus.

Which Müllerian anomalies are NOT typically associated with transverse lie?

Unicornuate uterus and uterus didelphys.

What obstetric complication has increased risk in Müllerian anomalies?

Cesarean section.

What hypertensive complication may be associated with Müllerian anomalies?

Pregnancy-induced hypertension (PIH).

What gynecological complication can result from outflow tract obstruction?

Hematometra.

What can hematometra lead to?

Endometriosis.

What symptom commonly results from Müllerian/outflow tract obstruction?

Dysmenorrhea.

Which Müllerian anomaly is specifically associated with dysmenorrhea?

Unicornuate uterus.

What gynecological bleeding abnormality may occur with Müllerian anomalies?

AUB (abnormal uterine bleeding).