Case report: A rare case of congenital vulvar malformation that is often overlooked

Case report: A rare case of congenital vulvar malformation that is often overlooked | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Case Report Case report: A rare case of congenital vulvar malformation that is often overlooked Yangyang Rao, Xialing Zhu, Min Chen, aqiang zhu This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9887434/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 20 You are reading this latest preprint version Abstract Purpose This study explores the clinical features, diagnostic criteria, and optimal timing for surgery in primary labia minora fusion, a rare congenital vulvar malformation, emphasizing that appropriate surgical timing can reduce the impact of retrograde menstrual flow and minimize long-term complications. Methods Retrospective analysis of clinical data from a 17-year-old patient with primary labia minora fusion. Results The patient underwent labiaplasty and perineal reconstruction, with good postoperative recovery. Dysmenorrhea symptoms were significantly alleviated compared to preoperatively, and the patient is able to resume normal sexual activity. Conclusion Primary labia minora fusion is extremely rare and is often mistaken for an anatomical variation that does not affect health. However, this deformity can cause functional low vaginal obstruction, resulting in retrograde menstrual flow and progressive dysmenorrhea, and increasing the risk of subsequent endometriosis. Once diagnosed, it is recommended to undergo surgical reconstruction as soon as possible, rather than postponing it until sexual intercourse becomes difficult or severe symptoms occur. labia minora fusion vulvar malformation dysmenorrhea Figures Figure 1 Figure 2 Figure 3 Introduction Female vulvar and vaginal malformations are caused by abnormal development of the terminal part of the Müllerian ducts and/or the urogenital sinus malformation during the embryonic stage. They are a rare type of female reproductive tract malformations[ 1 – 2 ].In this disease spectrum, common diseases include congenital absence of the vagina, vaginal atresia, vaginal septum, vaginal septum, vaginal oblique septum, hymenal atresia, etc. Besides, there are also some special types of vulvar-vaginal malformations that have rarely been reported. These malformations have complex and diverse clinical manifestations and often coexist with abnormalities in the urinary system, anus, and rectum. They are prone to misdiagnosis.This case reports a rare and specific type of vulvar malformatio,that is Primary labia minora fusion. By reviewing the literature, this study focuses on the diagnosis and differential diagnosis of this malformation, the selection of surgical timing, and the prevention of long-term complications, with the aim of enhancing clinicians' understanding of this type of disease, facilitating early diagnosis, and ensuring the implementation of appropriate treatment. Case Presentation The patient is a 17-year-old female, unmarried and has a stable boyfriend.Due to "having discovered vulvar deformity for 3 years, experiencing dysmenorrhea for 2 years, and being unable to have sexual intercourse", she visited our hospital's gynecology department in June 2023.Menstrual history and past medical history:She had her first menstrual period at the age of 14. Her menstrual cycle was regular. When she discovered that the menstrual blood and urine were expelled from the same opening, she went to another hospital for treatment. She was diagnosed with "genital malformation" and was advised to undergo surgery. However, the patient did not accept the surgery because it did not affect her life.One year after menarche, dysmenorrhea began to occur and gradually worsened. During menstruation, painkillers were often needed to be taken.She has no history of urinary incontinence or chronic pelvic pain during non-menstrual periods, and no history of external genital trauma, infection or local medication.Family history: The parents did not marry as close relatives, and the mother had no history of taking any medication during pregnancy.Physical examination: Height 168 cm, weight 56 kg. Both breasts are developing normally, pubic hair is visible, both large labia are normal, there is no normal female vaginal fissure. The prepuce of the clitoris is covered by the perineal skin from the anus to the pubic body. The urethral opening and vaginal opening cannot be exposed. There is an opening below the clitoris, with a diameter of approximately 0.5 cm. Urine and menstrual blood flow out through this opening. The anus is normal (Fig. 1 a).Auxiliary examinations: Chromosome karyotype is 46XX. The magnetic resonance imaging(MRI): The morphology and signal of the uterus, both ovaries, and the upper part of the vagina showed no abnormalities (Fig. 1 b, 1 c). A small amount of liquid signal was observed at the distal end of the vagina (above the fusion level), suggesting possible hematoma (Fig. 1 d).No abnormalities were detected by transrectal ultrasound and urinary system ultrasound. Sex hormone tests are all within normal ranges. CA125is 21.6 U/L. The results of the vaginal secretion test showed a positive reaction to the sialidase test.Based on the above information, our diagnosis is Primary labia minora fusion. we performed a small labia augmentation and perineal reconstruction surgery on her under general anesthesia.During the operation, a 6-sized cervical dilation rod was inserted through the external vaginal opening and then moved into the vagina, making a vertical downward guide.the skin and mucous membranes of the fusion area are cut in the middle from top to bottom. At this point, the normal vaginal vestibule below is completely exposed, allowing for the clear visualization of the urethra and vaginal opening (Fig. 2a).Then we used 3 − 0 absorbable sutures to reconstruct the labia minora and the posterior labial union. It can be seen that the edges of the vaginal vestibule after suturing present a serrated shape(Fig. 2b).A urinary catheter was placed after the operation for 2 days. After the catheter was removed, the patient's urinary control function was normal. External application of estrogen ointment was used for 2 weeks to promote mucosal healing and prevent re-adhesion. Three months after the surgery, the patient came to my clinic (unfortunately, she refused to have her vulva photographed). The patient's menstrual blood and urine were now being expelled through different orifices, the dysmenorrhea had significantly improved compared to before the surgery, no oral painkillers were needed, and vaginal sexual intercourse had been successfully completed. Discussion Primary labia minora fusion refers to the fusion of the midline of the inner labia that exists at birth. It is caused by the persistence of the distal urogenital sinus. The degree to which the fused inner labia cover the urethral opening and the external vaginal opening can vary, and it can be classified as complete or partial covering of the urethral opening and the external vaginal opening(Fig. 3 a, 3 b).Occasionally, it may be accompanied by urinary tract infections, ureteral dilation, and hydronephrosis. After puberty, it may also be associated with vaginal or uterine cavity blood accumulation and pelvic masses.The physical examination revealed that there was a layer of perineal skin tissue covering the perineal opening and the normal anal opening, while the vestibule of the vagina, the urethral and vaginal openings were concealed by it. A normal uterus, cervix and bilateral appendages were present, and there was a low incidence of other accessory mesonephric duct developmental abnormalities [ 3 – 4 ]. After a clear diagnosis of Primary labia minora fusion, surgical treatment is the best option. The surgical method is simple and effective.Reviewing this case, the patient was diagnosed at the onset of menstruation. However, due to the absence of obvious symptoms, the patient refused the surgery. Three years later, severe dysmenorrhea gradually worsened, suggesting that menstrual blood reflux had occurred.Therefore, the drainage channel for menstrual blood is not completely blocked. It is still wide enough to cause an increase in pressure within the vagina, thereby facilitating the reverse flow of menstrual blood through the fallopian tubes into the pelvic cavity.Poor drainage of menstrual blood can also increase the risk of infection. During the vaginal secretion examination for the patient, we found that the sialidase test was positive, indicating the presence of bacterial vaginosis.In cases of obstructive malformations such as septate uterus and uterine agenesis, there is ample evidence indicating that delayed surgery is associated with a higher incidence of endometriosis and chronic pelvic pain [ 5 – 6 ].The preoperative MRI of this patient showed a small amount of fluid accumulation at the distal end of the vagina, confirming the existence of functional obstruction.After the surgery,The dysmenorrhea was significantly relieved, further confirming that the dysmenorrhea was caused by the obstruction. Therefore, we believe that congenital fusion of the labia minora should be regarded as a functional low-level vaginal obstruction. The timing of the surgery should be based on factors such as whether the obstruction affects urine discharge or if there are recurrent urinary tract infections. For asymptomatic patients, it is recommended to undergo surgical reconstruction after the onset of menstruation, rather than waiting until there are difficulties in sexual life or persistent dysmenorrhea before addressing the issue. Summary This case not only provides a detailed description of the clinical features, but also focuses on exploring the association between this malformation and the risks of progressive dysmenorrhea and endometriosis. Primary fusion of the labia minora not only affects sexual intercourse function, but more importantly, may cause functional low vaginal obstruction, resulting in retrograde menstrual flow, progressive dysmenorrhea, and increasing the risk of secondary endometriosis. The accurate diagnosis depends on meticulous physical examination, chromosome karyotype, pelvic MRI and urinary system ultrasound. Once diagnosed, especially after the onset of menarche, it is recommended to perform labia minora plastic surgery and perineal weight reconstruction as soon as possible, rather than postponing it until sexual intercourse difficulties or severe symptoms occur. Declarations Ethics statement Written informed consent was obtained from the individual(s) for the publication of any potentially identifiable images or data included in this article. Funding no funding Data availability No data was used for the research described in the article. Author contributions All authors contributed to the study conception and design. The operation on this patient was performed by YR and XZ. Material preparation, data collection , and analysis were performed by YR、AZ and MC. All authors have read and approved the final version of the manuscript. Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Acknowledgments We thank the patient for agreeing to let us report on this case report. References Roly ZY, Backhouse B, Cutting A, Tan TY, Sinclair AH, Ayers KL, Major AT, Smith CA. The cell biology and molecular genetics of Müllerian duct development. Wiley Interdiscip Rev Dev Biol. 2018;7(3):1–13. Mullen RD, Behringer RR. Molecular genetics of Müllerian duct formation, regression and differentiation. Sex Dev. 2014;8(5):281–96. Acién P, Navarro V, Acién M. Embryological-clinical classification of female genital tract malformations - a review and update. Reprod Biomed Online. 2025 Jul;51(1):104751. Liang Z, Chen J, Yu X, Zhu L. Persistent Labial Minora Fusion in Reproductive Age Women: A Retrospective Case Series of Nine Patients and Review of Literature. Organogenesis. 2021 Apr 3;17(1-2):20-25. Bhamidipaty-Pelosi S, Kyei-Barffour I, Volpert M, O'Neill N, Grimshaw A, Eriksson L, Vash-Margita A, Pelosi E. Müllerian anomalies and endometriosis: associations and phenotypic variations. Reprod Biol Endocrinol. 2024 Dec 19;22(1):157. Sanfilippo JS, Wakim NG, Schikler KN, Yussman MA. Endometriosis in association with uterine anomaly. Am J Obstet Gynecol. 1986 Jan;154(1):39-43. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 27 Jun, 2026 Reviews received at journal 27 Jun, 2026 Reviewers agreed at journal 27 Jun, 2026 Reviews received at journal 24 Jun, 2026 Reviewers agreed at journal 24 Jun, 2026 Reviews received at journal 23 Jun, 2026 Reviews received at journal 23 Jun, 2026 Reviews received at journal 21 Jun, 2026 Reviewers agreed at journal 21 Jun, 2026 Reviews received at journal 19 Jun, 2026 Reviewers agreed at journal 18 Jun, 2026 Reviewers agreed at journal 18 Jun, 2026 Reviewers agreed at journal 18 Jun, 2026 Reviewers agreed at journal 18 Jun, 2026 Reviewers agreed at journal 18 Jun, 2026 Reviewers invited by journal 18 Jun, 2026 Editor invited by journal 09 Jun, 2026 Editor assigned by journal 03 Jun, 2026 Submission checks completed at journal 03 Jun, 2026 First submitted to journal 01 Jun, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9887434","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":665325232,"identity":"2756c15f-87a8-4eb1-b1dc-6a6fcdc40a55","order_by":0,"name":"Yangyang 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15:40:05","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9887434/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9887434/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":113257951,"identity":"fc8859ec-3bcb-4d0a-99ad-1724111896f3","added_by":"auto","created_at":"2026-06-28 16:52:26","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":309146,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003e(a) \u003c/strong\u003eThe actual picture of the patient's external genitalia. \u003cstrong\u003e(b) \u003c/strong\u003eThe MRI results show that there are normal structures of the uterus and both ovaries. \u003cstrong\u003e(c) \u003c/strong\u003eThe MRI results show the upper part of the vagina showed no abnormalities . \u003cstrong\u003e(d) \u003c/strong\u003eThe MRI results show\u003cstrong\u003e \u003c/strong\u003ea small amount of liquid signal was observed at the distal end of the vagina (above the fusion level).\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-9887434/v1/0993b53b64b521477c9a7273.png"},{"id":113258165,"identity":"27076a6c-0873-426a-9fc7-7da0b272d1bb","added_by":"auto","created_at":"2026-06-28 16:55:41","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":338747,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003e(a) \u003c/strong\u003ePictures during the surgery. \u003cstrong\u003e(b) \u003c/strong\u003ePictures after the surgery\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-9887434/v1/4ef722b8fe8ca4a8aa822ae7.png"},{"id":113258176,"identity":"c940b8c8-de45-478d-b36f-d815e25fb586","added_by":"auto","created_at":"2026-06-28 16:55:56","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":134566,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003e(a)\u003c/strong\u003eThe urethral opening and the external genital opening are completely covered. \u003cstrong\u003e(b) \u003c/strong\u003eThe urethral opening and the external genital area opening are covered.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-9887434/v1/090d84e0213b424e15f245fe.png"},{"id":113271436,"identity":"ce7f294b-3057-4605-97ec-423669eb5b30","added_by":"auto","created_at":"2026-06-28 20:12:57","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1156609,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9887434/v1/51b25063-37ab-421f-afac-49501f2acb98.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Case report: A rare case of congenital vulvar malformation that is often overlooked","fulltext":[{"header":"Introduction","content":"\u003cp\u003eFemale vulvar and vaginal malformations are caused by abnormal development of the terminal part of the M\u0026uuml;llerian ducts and/or the urogenital sinus malformation during the embryonic stage. They are a rare type of female reproductive tract malformations[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e].In this disease spectrum, common diseases include congenital absence of the vagina, vaginal atresia, vaginal septum, vaginal septum, vaginal oblique septum, hymenal atresia, etc. Besides, there are also some special types of vulvar-vaginal malformations that have rarely been reported. These malformations have complex and diverse clinical manifestations and often coexist with abnormalities in the urinary system, anus, and rectum. They are prone to misdiagnosis.This case reports a rare and specific type of vulvar malformatio,that is Primary labia minora fusion. By reviewing the literature, this study focuses on the diagnosis and differential diagnosis of this malformation, the selection of surgical timing, and the prevention of long-term complications, with the aim of enhancing clinicians' understanding of this type of disease, facilitating early diagnosis, and ensuring the implementation of appropriate treatment.\u003c/p\u003e"},{"header":"Case Presentation","content":"\u003cp\u003eThe patient is a 17-year-old female, unmarried and has a stable boyfriend.Due to \"having discovered vulvar deformity for 3 years, experiencing dysmenorrhea for 2 years, and being unable to have sexual intercourse\", she visited our hospital's gynecology department in June 2023.Menstrual history and past medical history:She had her first menstrual period at the age of 14. Her menstrual cycle was regular. When she discovered that the menstrual blood and urine were expelled from the same opening, she went to another hospital for treatment. She was diagnosed with \"genital malformation\" and was advised to undergo surgery. However, the patient did not accept the surgery because it did not affect her life.One year after menarche, dysmenorrhea began to occur and gradually worsened. During menstruation, painkillers were often needed to be taken.She has no history of urinary incontinence or chronic pelvic pain during non-menstrual periods, and no history of external genital trauma, infection or local medication.Family history: The parents did not marry as close relatives, and the mother had no history of taking any medication during pregnancy.Physical examination: Height 168 cm, weight 56 kg. Both breasts are developing normally, pubic hair is visible, both large labia are normal, there is no normal female vaginal fissure. The prepuce of the clitoris is covered by the perineal skin from the anus to the pubic body. The urethral opening and vaginal opening cannot be exposed. There is an opening below the clitoris, with a diameter of approximately 0.5 cm. Urine and menstrual blood flow out through this opening. The anus is normal (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ea).Auxiliary examinations: Chromosome karyotype is 46XX. The magnetic resonance imaging(MRI): The morphology and signal of the uterus, both ovaries, and the upper part of the vagina showed no abnormalities (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eb, \u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ec). A small amount of liquid signal was observed at the distal end of the vagina (above the fusion level), suggesting possible hematoma (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ed).No abnormalities were detected by transrectal ultrasound and urinary system ultrasound. Sex hormone tests are all within normal ranges. CA125is 21.6 U/L. The results of the vaginal secretion test showed a positive reaction to the sialidase test.Based on the above information, our diagnosis is Primary labia minora fusion.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003ewe performed a small labia augmentation and perineal reconstruction surgery on her under general anesthesia.During the operation, a 6-sized cervical dilation rod was inserted through the external vaginal opening and then moved into the vagina, making a vertical downward guide.the skin and mucous membranes of the fusion area are cut in the middle from top to bottom. At this point, the normal vaginal vestibule below is completely exposed, allowing for the clear visualization of the urethra and vaginal opening (Fig.\u0026nbsp;2a).Then we used 3\u0026thinsp;\u0026minus;\u0026thinsp;0 absorbable sutures to reconstruct the labia minora and the posterior labial union. It can be seen that the edges of the vaginal vestibule after suturing present a serrated shape(Fig.\u0026nbsp;2b).A urinary catheter was placed after the operation for 2 days. After the catheter was removed, the patient's urinary control function was normal. External application of estrogen ointment was used for 2 weeks to promote mucosal healing and prevent re-adhesion.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThree months after the surgery, the patient came to my clinic (unfortunately, she refused to have her vulva photographed). The patient's menstrual blood and urine were now being expelled through different orifices, the dysmenorrhea had significantly improved compared to before the surgery, no oral painkillers were needed, and vaginal sexual intercourse had been successfully completed.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003ePrimary labia minora fusion refers to the fusion of the midline of the inner labia that exists at birth. It is caused by the persistence of the distal urogenital sinus. The degree to which the fused inner labia cover the urethral opening and the external vaginal opening can vary, and it can be classified as complete or partial covering of the urethral opening and the external vaginal opening(Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e3\u003c/span\u003ea,\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e3\u003c/span\u003eb).Occasionally, it may be accompanied by urinary tract infections, ureteral dilation, and hydronephrosis. After puberty, it may also be associated with vaginal or uterine cavity blood accumulation and pelvic masses.The physical examination revealed that there was a layer of perineal skin tissue covering the perineal opening and the normal anal opening, while the vestibule of the vagina, the urethral and vaginal openings were concealed by it. A normal uterus, cervix and bilateral appendages were present, and there was a low incidence of other accessory mesonephric duct developmental abnormalities [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eAfter a clear diagnosis of Primary labia minora fusion, surgical treatment is the best option. The surgical method is simple and effective.Reviewing this case, the patient was diagnosed at the onset of menstruation. However, due to the absence of obvious symptoms, the patient refused the surgery. Three years later, severe dysmenorrhea gradually worsened, suggesting that menstrual blood reflux had occurred.Therefore, the drainage channel for menstrual blood is not completely blocked. It is still wide enough to cause an increase in pressure within the vagina, thereby facilitating the reverse flow of menstrual blood through the fallopian tubes into the pelvic cavity.Poor drainage of menstrual blood can also increase the risk of infection. During the vaginal secretion examination for the patient, we found that the sialidase test was positive, indicating the presence of bacterial vaginosis.In cases of obstructive malformations such as septate uterus and uterine agenesis, there is ample evidence indicating that delayed surgery is associated with a higher incidence of endometriosis and chronic pelvic pain [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].The preoperative MRI of this patient showed a small amount of fluid accumulation at the distal end of the vagina, confirming the existence of functional obstruction.After the surgery,The dysmenorrhea was significantly relieved, further confirming that the dysmenorrhea was caused by the obstruction. Therefore, we believe that congenital fusion of the labia minora should be regarded as a functional low-level vaginal obstruction. The timing of the surgery should be based on factors such as whether the obstruction affects urine discharge or if there are recurrent urinary tract infections. For asymptomatic patients, it is recommended to undergo surgical reconstruction after the onset of menstruation, rather than waiting until there are difficulties in sexual life or persistent dysmenorrhea before addressing the issue.\u003c/p\u003e"},{"header":"Summary","content":"\u003cp\u003eThis case not only provides a detailed description of the clinical features, but also focuses on exploring the association between this malformation and the risks of progressive dysmenorrhea and endometriosis. Primary fusion of the labia minora not only affects sexual intercourse function, but more importantly, may cause functional low vaginal obstruction, resulting in retrograde menstrual flow, progressive dysmenorrhea, and increasing the risk of secondary endometriosis. The accurate diagnosis depends on meticulous physical examination, chromosome karyotype, pelvic MRI and urinary system ultrasound. Once diagnosed, especially after the onset of menarche, it is recommended to perform labia minora plastic surgery and perineal weight reconstruction as soon as possible, rather than postponing it until sexual intercourse difficulties or severe symptoms occur.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics statement\u0026nbsp;\u003c/strong\u003eWritten informed consent was obtained from the individual(s) for the publication of any potentially identifiable images or data included in this article.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u0026nbsp;\u003c/strong\u003eno funding\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e No data was used for the research described in the article.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u0026nbsp;\u003c/strong\u003eAll authors contributed to the study conception and design. The operation \u003cins cite=\"mailto:Accdon\" datetime=\"2024-07-17T09:49\"\u003eon\u003c/ins\u003e this patient was performed by YR and XZ. Material preparation, data collection\u003cins cite=\"mailto:Accdon\" datetime=\"2024-07-17T09:49\"\u003e,\u003c/ins\u003e and analysis were performed by YR、AZ\u003cins cite=\"mailto:Accdon\" datetime=\"2024-07-17T09:49\"\u003e\u0026nbsp;and\u003c/ins\u003e MC. All authors \u003cins cite=\"mailto:Accdon\" datetime=\"2024-07-17T09:49\"\u003ehave\u0026nbsp;\u003c/ins\u003eread and approved the final \u003cins cite=\"mailto:Accdon\" datetime=\"2024-07-17T09:49\"\u003eversion of the\u0026nbsp;\u003c/ins\u003emanuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDeclaration of competing interest\u0026nbsp;\u003c/strong\u003eThe authors declare that they have no known competing financial interests or personal relationships that could have appeared to\u0026nbsp;\u003c/p\u003e\n\u003cp\u003einfluence the work reported in this paper.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgments\u0026nbsp;\u003c/strong\u003eWe thank the patient for agreeing to let us report on this case report.\u0026nbsp;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eRoly ZY, Backhouse B, Cutting A, Tan TY, Sinclair AH, Ayers KL, Major AT, Smith CA. The cell biology and molecular genetics of M\u0026uuml;llerian duct development. Wiley Interdiscip Rev Dev Biol. 2018;7(3):1\u0026ndash;13. \u003c/li\u003e\n\u003cli\u003eMullen RD, Behringer RR. Molecular genetics of M\u0026uuml;llerian duct formation, regression and differentiation. Sex Dev. 2014;8(5):281\u0026ndash;96. \u003c/li\u003e\n\u003cli\u003eAci\u0026eacute;n P, Navarro V, Aci\u0026eacute;n M. Embryological-clinical classification of female genital tract malformations - a review and update. Reprod Biomed Online. 2025 Jul;51(1):104751. \u003c/li\u003e\n\u003cli\u003eLiang Z, Chen J, Yu X, Zhu L. Persistent Labial Minora Fusion in Reproductive Age Women: A Retrospective Case Series of Nine Patients and Review of Literature. Organogenesis. 2021 Apr 3;17(1-2):20-25. \u003c/li\u003e\n\u003cli\u003eBhamidipaty-Pelosi S, Kyei-Barffour I, Volpert M, O\u0026apos;Neill N, Grimshaw A, Eriksson L, Vash-Margita A, Pelosi E. M\u0026uuml;llerian anomalies and endometriosis: associations and phenotypic variations. Reprod Biol Endocrinol. 2024 Dec 19;22(1):157. \u003c/li\u003e\n\u003cli\u003eSanfilippo JS, Wakim NG, Schikler KN, Yussman MA. Endometriosis in association with uterine anomaly. Am J Obstet Gynecol. 1986 Jan;154(1):39-43. \u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-womens-health","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bmwh","sideBox":"Learn more about [BMC Women's Health](http://bmcwomenshealth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bmwh/default.aspx","title":"BMC Women's Health","twitterHandle":"","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"labia minora fusion, vulvar malformation, dysmenorrhea","lastPublishedDoi":"10.21203/rs.3.rs-9887434/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9887434/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003ePurpose\u003c/strong\u003e This study explores the clinical features, diagnostic criteria, and optimal timing for surgery in primary labia minora fusion, a rare congenital vulvar malformation, emphasizing that appropriate surgical timing can reduce the impact of retrograde menstrual flow and minimize long-term complications.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods \u003c/strong\u003eRetrospective analysis of clinical data from a 17-year-old patient with primary labia minora fusion.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults \u003c/strong\u003eThe patient underwent labiaplasty and perineal reconstruction, with good postoperative recovery. Dysmenorrhea symptoms were significantly alleviated compared to preoperatively, and the patient is able to resume normal sexual activity.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion\u003c/strong\u003e Primary labia minora fusion is extremely rare and is often mistaken for an anatomical variation that does not affect health. However, this deformity can cause functional low vaginal obstruction, resulting in retrograde menstrual flow and progressive dysmenorrhea, and increasing the risk of subsequent endometriosis. Once diagnosed, it is recommended to undergo surgical reconstruction as soon as possible, rather than postponing it until sexual intercourse becomes difficult or severe symptoms occur.\u003c/p\u003e","manuscriptTitle":"Case report: A rare case of congenital vulvar malformation that is often overlooked","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-06-28 10:37:08","doi":"10.21203/rs.3.rs-9887434/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-06-27T13:08:23+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-06-27T11:36:08+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"79973964431901512616119034527228120019","date":"2026-06-27T11:33:30+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-06-24T06:22:51+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"20798065359815399165864358833579932110","date":"2026-06-24T06:17:51+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-06-24T00:28:13+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-06-23T21:30:13+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-06-21T10:35:41+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"328405385085966153053280012999387176425","date":"2026-06-21T10:33:18+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-06-19T11:20:43+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"242274765649208154341584967160741086488","date":"2026-06-18T19:33:40+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"95550991394957873920992753530638335526","date":"2026-06-18T14:06:04+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"50567426082882119895057286893896277295","date":"2026-06-18T09:22:53+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"147760404336722437416357184861198654328","date":"2026-06-18T09:00:50+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"76512955447709946442347186526016712529","date":"2026-06-18T08:43:54+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-06-18T08:39:33+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2026-06-09T12:22:39+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-06-04T00:48:05+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-06-04T00:47:20+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Women's Health","date":"2026-06-01T15:23:38+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-womens-health","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bmwh","sideBox":"Learn more about [BMC Women's Health](http://bmcwomenshealth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bmwh/default.aspx","title":"BMC Women's Health","twitterHandle":"","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"72735e10-7a7a-4a13-a408-9554bcbb93f4","owner":[],"postedDate":"June 28th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-07-18T00:53:12+00:00","versionOfRecord":[],"versionCreatedAt":"2026-06-28 10:37:08","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9887434","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9887434","identity":"rs-9887434","version":["v1"]},"buildId":"7rjqhiLT3MXkJMwkYKINL","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}