3.1.1: Uterine Malformations
- Page ID
- 94910
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)3.1.1.1 Definition and Clinical Presentation
These are malformations that occur during embryogenesis due to abnormal development of the Müllerian duct(s). Based on the type of malformation, the clinical presentations are variable. These include amenorrhea, infertility, recurrent miscarriages/abortions, pain, preterm birth, cervical insufficiency, premature rupture of membranes, fetal malpresentation, fetal growth restriction, placental abruption, placenta previa, placental retention, and cesarean birth 1. Women with canalization defect unification defect are less likely to achieve clinical pregnancy and live birth; they were more likely to experience spontaneous early pregnancy loss after In-Vitro Fertilization Embryo Transfer (IVF-ET) when compared with women with normal uterus.1
3.1.1.2 Types
The following is based on the American Fertility Society (AFS). The following malformations are recognized (Figure 3.1.1).2
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Class I
Müllerian agenesis (absent uterus): Hypoplasia (marked reduction in the size of the uterus) or agenesis (complete absence) of parts of the uterus. The latter includes
- Vaginal hypoplasia or agenesis
- Cervical hypoplasia or agenesis
- Fundal hypoplasia or agenesis
- Tubal hypoplasia or agenesis
- Combined hypoplasia and agenesis of different parts of the uterus
Mayer-Rokitansky-Kuster-Hauser syndrome is a congenital aplasia of the uterus and the upper part (2/3) of the vagina in women showing normal development of secondary sexual characteristics and a normal 46, XX karyotype. It affects at least 1 out of 4500 women and presents with primary amenorrhea
Figure 3.1.1. Diverse uterine malformations in humans.
Image Source: Sciencia58. "Uterine malformation". (2023) This work is openly licensed via CC0 Creative Commons license. Available from Wikimedia Commons.
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Class II
Unicornuate uterus: There is a partial or complete lack of one Müllerian duct, leading to an imaging abnormality, a "banana-shaped uterus." One Müllerian duct gives rise to one half of the uterus, which fuses with the other half, developing from the other Müllerian duct to form a normal uterus. Several subtypes of the unicornuate uterus (Figure 3.1.2) include
- A hemiuterus without a rudimentary horn
- A hemiuterus with a non-functional rudimentary horn (no cavity in the rudimentary horn)
- A hemiuterus with a functional, communicating rudimentary horn
- A hemiuterus with a functional, non-communicating rudimentary horn
Figure 3.1.2 Types of unicornuate uterus anomaly.
Image Source: Ladke, Pooja, Ashish N Ambhore, Avinash Dhok, Kajal Mitra, and Vrushali Dalvi. “A Unique Case of Unicornuate Uterus With a Non-Communicating Rudimentary Horn and Hematometra.” Cureus 14, No. 12 (2022): e32640. This work is openly licensed via CC-BY license. doi.org/10.7759/cureus.32640
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Class III
Uterus didelphys/didelphis (double uterus): This anomaly results from the failure of fusion of both Müllerian ducts, leading to the formation of a "double uterus." It might also be associated with a double cervix and a vaginal partition.
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Class IV
Bicornuate uterus (uterus with two horns): This anomaly results from the failure of fusion of only the upper parts of the Müllerian system, leading to a bifurcated upper part of the uterus. The caudal (lower) part of the uterus is normal.
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Class V
Septate uterus (uterine septum or partition): After the fusion of the two Müllerian ducts, the septum between them persists, leading to the splitting of the uterine cavity. The persistent septum could be complete or partial.
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Class VI
DES drug-related uterus: Diethylstilbestrol (DES) exposure during pregnancy can cause uterine abnormalities, including
- Uterine shape: T-shaped or hypoplastic cavity
- Uterine muscle layers: disruption of the development of the uterine muscle layers
- Uterotubal junction: maldevelopment of the uterotubal junction
- Vaginal epithelium non-stratification and lack of vaginal glands resorption leading to vaginal adenosis
The American Society for Reproductive Medicine (ASRM) Task Force on Mullerian Anomalies Classification updated the original AFS classification to include additional anomalies. For further details, please refer to ASRM mullerian anomalies classification 2021.
Glossary Terms
- Embryogenesis
- Complicated process by which a fertilized egg develops into an embryo
- Müllerian ducts
- Pair of ducts near the Wolffian ducts in a developing embryo. In the male embryo, they degenerate with the appearance of testicular anti-Müllerian hormone
- Placental abruption
- Premature separation of the normally implanted placenta from the uterus
- Placenta previa
- Abnormal placentation in which the placenta implants in the lower segment of the uterus (the zone of dilation) and may cover part or all of the opening of the cervix
- Placental retention
- Occurs when the placenta fails to be expelled after the birth of the fetus. A placenta is retained when the uterus fails to contract after the delivery of content, or when the placenta is abnormally attached to the myometrium
Footnotes
- Kang, Jia, and Jie Qiao. “Impact of Congenital Uterine Anomalies on Reproductive Outcomes of IVF/ICSI-Embryo Transfer: A Retrospective Study.” European Journal of Medical Research 29, no. 1 (2024). doi.org/10.1186/s40001-023-01544-2
- Buttram, V. C., V. Gomel, A. Siegler, A. DeCherney, W. Gibbons, and C. March. “The American Fertility Society Classifications of Adnexal Adhesions, Distal Tubal Occlusion, Tubal Occlusion Secondary to Tubal Ligation, Tubal Pregnancies, Müllerian Anomalies and Intrauterine Adhesions.” Fertility and Sterility 49, no. 6 (June 1, 1988): 944–55. doi.org/10.1016/S0015-0282(16)59942-7
- Herlin, Morten Krogh, Michael Bjørn Petersen, and Mats Brännström. “Mayer-Rokitansky-Küster-Hauser (MRKH) Syndrome: A Comprehensive Update.” Orphanet Journal of Rare Diseases, 15, No. 214 (2020). doi.org/10.1186/s13023-020-01491-9
Image Acknowledgements
Ladke, Pooja, Ashish N Ambhore, Avinash Dhok, Kajal Mitra, and Vrushali Dalvi. “A Unique Case of Unicornuate Uterus With a Non-Communicating Rudimentary Horn and Hematometra.” Cureus 14, No. 12 (2022): e32640. This work is openly licensed via CC-BY license. doi.org/10.7759/cureus.32640