Pocket ObGyn – Müllerian anomalies
See Abbreviations
Definitions and Epidemiology (Hum Reprod Update 2011;17:761)
- An anomaly of the uterus, tubes, or upper vagina due to failure of dev, fusion, or resorption of Müllerian structures 5–6% of women (arcuate uterus 3.9%, septate uterus 2.3%, bicornuate 0.4%, uni- cornuate 0.3%, didelphys 0.3%). to 8% w/ infertility. to 13% w/ recurrent mis- carriage. to 25% w/ mixed infertility & recurrent miscarriage. Many also have a GU abnormality.
Etiology (Fritz MA, Speroff L. Clinical Gynecologic Endocrinology & Infertility. Philadelphia, PA: Lippincott Williams & Wilkins; 2011.)
- Sporadic: Multifactorial & 46 XX (92%); sex chromo mosaicism (8%).
- Risk factors: Hypoxia during Preg, MTX, DES, thalidomide, radiation, viral infxn
- Vertical fusion failure (canalization) ® urogenital sinus & Müllerian tubercle separate
- Lateral fusion failure (duplication) ® failure to merge bilateral Müllerian ducts
- Dev of the uterus, fallopian tubes, & upper vagina:
2 Müllerian (paramesonephric) ducts form from celomic epithelium beside the wolffian (mesonephric) ducts. In the absence of the SRY gene on the Y chromo & subseq MIS or AMH, Müllerian ducts proliferate & grow caudally & medially extending from the vaginal plate of the urogenital sinus to beside the developing ovary. In absence of testosterone, wolffian ducts involute. Canalization of the ducts occurs w/ a cranial lumen opening into peritoneal cavity. The paired ducts fuse in the midline forming the body of the uterus & the unfused lateral arms form the fallopian tubes. Resorption of medial aspects.
- Dev of urogenital sinus forms lower vagina, bladder, urethra
Urogenital sinus develops from the ventral portion of the cloaca (terminal hindgut; confluence of the urethra, rectum, & vagina). The caudal aspect of the parameso- nephric ducts fuses w/ the urogenital sinus to form the vaginal & cervix.
Figure 8.1 Types of congenital uterine anomalies
Classification of Müllerian Anomalies
(continued)
Figure 8.1 (Continued )
(From Fritz MA, Speroff L. Clinical Gynecologic Endocrinology & Infertility. Philadelphia, PA: Lippincott Williams & Wilkins; 2011)
Clinical Manifestations (Curr Opin Obstet Gynecol 2010;22:381; Fertil Steril 2008;89:219)
- Most often asymptomatic w/ nml secondary sex characteristics
- Sx can include primary amenorrhea or changes in menstrual cycle (uterine or vaginal malformations); dysmenorrhea or cyclic acute ± chronic pelvic pain;
Abn vaginal bleeding; foul-smelling vaginal discharge (worse at the time of menses); difficulty inserting a tampon; pelvic mass (from hematometra/hematocolpos); dyspareunia; infertility; recurrent Preg loss (esp septate uterus)
- Preg complications (higher rates of SAB, preterm birth, fetal malpresentation, labor dystocia, PPROM, placental abruption of previa, IUGR, & increased c-section) (Am J Obstet Gynecol 2011;205:558)
| Risk of pregnancy outcome by uterine anomaly | |||
| Preg loss (%) | Premature delivery (%) | Fetal survival (%) | |
| Bicornuate uterus | 40 | 62 | |
| Septate uterus | >60 | 6–28 | |
| Uterine didelphys | 35 | 19 | 60 |
| Unicornuate uterus | 44 | 25 | 43 |
| From Ribeiro SC. Müllerian duct anomalies: Review of current management. Sao Paulo Med J. 2009;127:92. | |||
Specific anomalies (Obstet Gynecol 2013;121:1134)
• Vaginal agenesis/MRKH syn
Müllerian agenesis of upper vagina, ± uterus/tubes ® blind pouch vagina. Affects 1 in 4000–10000 women. Nml ovarian & sexual dev. urinary tract, skeletal, & anter abdominal wall anomalies.
• Vaginal atresia
15% are segmental. Nml uterus, cervix, upper vagina. Primary amenorrhea. Hematocolpos ® cyclic pelvic pain. Ddx: Imperf hymen, transverse septum. Segmental has ³1 cm btw the upper & lower vaginal tract.
• Transverse vaginal septum
Defect in resorption, affects 1/2100–1/72000 women. Presents like vaginal agenesis. Preoperative dilation can thin the septum to improve mobilization of the vagina at repair
• Uterovaginal abnormalities (longitudinal vaginal septa)
Defect in resorption ® Preg loss, preterm deliv, dyspareunia, dysmenorrhea. 20% w/ renal anomalies. Up to 50% w/ endometriosis.
• Uterine didelphys
Defect in lateral fusion w/ double uterus & cervix ± double vaginas ® postmenar- chal dysmenorrhea, abd pain, palpable abdominal mass. Linked w/ ipsilateral renal agenesis (OHVIRA/Herlyn–Werner–Wunderlich syn)
• Unicornuate uterus
Only 1 Müllerian duct formed, w/ absent/incomplete contralateral side. 5% of all uterine anomalies; 1/4020–1/5400 . 74% have rudimentary horn, generally not communicating w/ hemiuterus. 40% w/ renal anomalies. 15% w/ endometriosis. Rarely extrapelvic or absent ovaries. Ectopic Preg can occur in uterine rudimen-
tary horn; for rupture ® prompt surgical mgmt ± MTX. Recommend removal of rudimentary horns prior to Preg. Obstetric & infertility complications: Late 1st & early 2nd trimester SAB (25%), decreased fecundity, preterm deliv (20%), 3rd trimester fetal demise (10%), placenta accreta, postpartum atony.
• Cervical atresia
4 categories: (1) Agenesis, (2) fragmentation, (3) fibrous cord, (4) obst. 50% also w/ vaginal agenesis. 33% w/ uterine anomalies. endometriosis, hematosalpinx, & pelvic adhesive dz. Rx unclear given very rare condition.
Diagnostic Workup/Studies (Fertil Steril 2008;89:219)
- Goal: Identify dilated/obstructed uterus &/or mass, pelvic anatomy, distance of an obstructed vagina from the perineum, thickness of a vaginal septum or atretic segment, & presence/absence of urinary tract anomalies
- Physical exam including pelvic ± rectal exam (adol/young adults). Exam under anesthesia ± vaginoscopy (pediatric pop).
- MRI is most sensitive imaging test for uterine anomalies & is preferred
- Pelvic US & HSG also imaging tools
- Vaginoscopy (gold std for vaginal or cervical anomalies)
- Laparoscopy (gold std for uterine anomalies)
- ± intraoperative ± karyotype.
Treatment and Medications (Fertil Steril 2008;89:1)
- Uterine/vaginal obst ® immediately relieve obst (Surg)
If unable to proceed to OR immediately, place Foley catheter to avoid urinary retention. Consider percutaneous drainage, laparoscopic drainage, continuous OCPs to suppress endometrial growth until surgical repair.
- Vaginal anomaly ® surgical or mechanical If not emergent, medical/ surgical intervention when emotionally mature/reproductive age. Vaginal dilators are used post-op to prevent stenosis. Overall pts have a satisfactory sex life similar to the nml pop. Discuss Preg options, IVF, surrogacy. Pts need multidisciplinary support including mental health providers & social work.
Progressive perineal dilation: 1st-line therapy as surgical neovagina stenosis & multi reoperations. More successful if greater depth of vaginal dimple, increased frequency of dilation, & sexual intercourse.
Surgical mgmt:
Vecchietti procedure (abdominal or laparoscopic technique w/ gradual traction on the vaginal dimple) ® creation of a neovagina in 6 mo for 90% of pts. Must use vaginal mold continuously for the 1st 3 mo post-op.
McIndoe neovagina (dissection btw the urethra & rectum) ® place split-thickness skin graft
Davydov neovagina (abdominal or laparoscopic-assisted technique w/ dissection of rectovesical space, mobilization of the peritoneum, creation of vaginal forni- ces, & attachment of the peritoneum to the introitus)
Williams vulvovaginoplasty (uses a vulvar flap to make a vaginal tube). Dilation is needed for a long period. Abn angle of neovagina.
Rotational flaps (use pudendal thigh, gracilis myocutaneous, labia minora, & other fasciocutaneous reconstruction). Also can create vagina from bowel.
- Septum ® hysteroscopic resxn of uterine or longitudinal vaginal Low or midtransverse vaginal septum approached vaginally; high septum & segmental vaginal atresia combine vaginal & abdominal approach. Pull through vaginoplasty if small length of atretic segment. Skin flaps or bowel if segment btw upper & lower vagina is larger.
- Bicornuate uterus – Strassman metroplasty unifies the 2 cavities. Rarely performed given difficulty & risk of future uterine rupture in
- Rudimentary horn, obstructed hemivaginas, ® laparoscopic resxn
- Cervical atresia ® hysterotomy & uterovaginal anastamosis vs. hysterectomy
- Didelphys, bicornuate rarely require Uterine septum outcomes improved w/ resxn if 1st trimester loss or desires IVF.