Uterine anomalies

The development of the female genital apparatus originates during embryogenesis from Muller's ducts from which the salpinges, uterus and the upper third of the vagina derive; the lower third of the vagina and the vulva (labia minora and labia majora) derive from the urogenital sinus; the clitoris originates from the genital tubercle¹. An arrest of the organogenetic stages can cause uterine and vaginal abnormalities of varying degrees. Congenital uterine malformations (CUMs) have an incidence of 5.5% in the general population, 8% in infertile patients,13% in women with a history of miscarriage, up to an incidence of 25% in women with previous miscarriage and history of infertility².

Clinic
Most women with CUM are asymptomatic. Among symptomatic patients, the extent and characteristics of symptoms vary2. Obstructive abnormalities may be associated with primary amenorrhoea, recurrent pelvic pain, dysmenorrhoea, pelvic mass. Non-obstructive uterine abnormalities such as septate uterus and dysmorphic T-shaped uterus correlate with infertility and pregnancy complications. Complete and partial septum uteri correlate with the worst reproductive outcomes such as reduced rate of conception, increased risk of miscarriage in the first trimester and fetal malpresentation at delivery. Unification defects (bicornuate and unicornuate uteri) do not appear to reduce fertility but are associated with an increased risk of adverse outcomes during pregnancy.

Classification
One of the most commonly used classifications is theESHRE/ESGE of 2013 by which all uterine malformations can be categorised^3,4.

_{ESHRE/ESGE classification of uterine anomalies}

UTERUS SEVENTH
It is the most frequent uterine malformation (55% of Muller anomalies) and is the consequence of incomplete reabsorption of the uterovaginal septum after fusion of Muller's ducts⁵. Two types of septum can be distinguished:

• complete septum: the septum completely divides the uterine cavity up to the OUI. Cervical and/or vaginal abnormalities may coexist.
• incomplete septum: the septum originates from the uterine fundus and does not reach the OUI.

The diagnosis of uterus septum is made by performing 3D ultrasound and confirmatory diagnostic hysteroscopy. Numerous classifications for the diagnosis have been developed over the years. According to the 2013 ESHRE/ESGE criteria, the ultrasound diagnosis of a septum uterus is made if the indentation of the uterine fundus on 3D evaluation is >50% of myometrial wall thickness⁴. According to the 2016 ASRM classification for the diagnosis of uterus septum it is necessary that the distance from the interostial line to the apex of the indentation is >1.5 cm and that the angle of indentation is < 90°.⁶. In 2018, the CUME classification was developed, the most accurate and reproducible in accordance with the opinion of most experts, for which a diagnosis of a septum is made if the depth of indentation is at least 1 cm ⁷ 

UTERO A T
The T-shaped uterus (T-shaped uterus or dysmorphic uterus) is an abnormality that correlates with infertility and/or repeated miscarriages due to difficult implantation of the blastocyst in the uterus⁷. In the literature, a pregnancy rate of 73% after hysteroscopic correction of the anomaly is reported with 48% of pregnancies conceived spontaneously without recourse to fertilisation techniques. L'3D ultrasound examination is based on three diagnostic criteria established by CUME: 1) lateral indentation angle ≤130°; 2) lateral indentation thickness ≥7mm; 3) angle T ≤40°.⁷.


Treatment
Individualised approach for each patient in consideration of ultrasound findings and medical history. In patients with a history of recurrent miscarriage, infertility and unfavourable obstetrical outcomes, hysteroscopic correction is indicated⁸. The treatment of the septum uterus consists of performing a hysteroscopic metroplasty with the aim of re-establishing a normal uterine cavity by removing the fibrotic septum, leaving a myometrial thickness at the bottom of 1 cm-1.5 cm. The hysteroscopic correction of the T-shaped uterus consists of incising the fibromuscular tissue of the uterine side walls in order to recreate a regular cavity.

Bibliography

1. 1. Buttram VC Jr, Gibbons WE. Mu€llerian anomalies: a proposed classification. An analysis of 144 cases. Fertil Steril 1979;32:40-6
   2. Chan YY et al: Reproductive outcomes in women with congenital uterine anomalies: a systematic review. Ultr Og Gyn 2011;38:371-382
   3. Grimbizis GF, Campo R; on Behalf of the SC of the CONUTA ESHRE/ESGE Working Group, Gordts G, Brucker S, Gergolet M, Tanos V, Li T-C, De Angelis C, Di Spiezio Sardo A. Clinical approach for the classification of congenital uterine malformations.Gynecol Surg 2012;9:119-129.
   4. Grigoris F. Grimbizis, Stephan Gordts, Attilio Di Spiezio Sardo, et al. The ESHRE/ESGE consensus on the classification of female genital tract congenital anomalies. Human Reproduction, Vol.28, No.8 pp. 2032-2044, 2013
   5. Heinonen PK. Complete septate uterus with longitudinal vaginal septum. Fertil Steril. 2006; 83(3):700
   6. Comparison of the ESHRE-ESGE and ASRM classifications of Müllerian duct anomalies in everyday practice
   7. Ludwin A, Martins WP, Nastri CO et al. Congenital Uterine Malformation by Experts (CUME): better criteria for distinguishing between normal/arcuate and septate uterus? Ultrasound Obstet Gynecol. 2018 Jan;51(1):101-109
   8. R.F. Valle, G.E. Ekpo et al. Hysteroscopic metroplasty for the septate uterus: review and meta-analysis. J Minim Invasive Gynecol, 20 (1) (2013), pp. 22-42

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