Imperforate Hymen: A Comprehensive Systematic Review

Imperforate hymen (IH) is an uncommon congenital anomaly of the female genital tract, with the hymen completely obstructing the vaginal opening. Despite the simple diagnosis and treatment of IH, missed or delayed diagnosis is often a clinical problem owing to its low incidence, nonspecific symptoms, or insufficient physical examination. The aim of this study is to identify the characteristics, clinical presentations, treatment modalities, and outcomes of imperforate hymen patients. In this study, a literature search of PubMed databases was performed for sources published up to 3 July 2018 for English-language studies with the term “imperforate hymen”. The literature review identified 251 citations and 155 articles (143 case reports, 12 case series) containing 253 patients who were finally included (two papers were not written in English). Among 236 postnatal patients, the mean age of the patients was 10.7 ± 4.7 years. Abdominal pain (54.2%), urinary retention (20.3%), abnormal menstruation (14.0%), dysuria (9.7%), increased urinary frequency (5.1%), severe presentation of renal failure (n = 5, 2.1%), and urinary tract infection (n = 1, 0.4%) were presented. Most patients diagnosed with the condition underwent surgical treatment (83.5%), most of whom were treated via a hymenotomy (35.2%) and hymenectomy (36.4%), and the use of prophylactic antibiotics were only used in 7 patients. There were no differences in outcomes between two surgical methods. In addition, 141 (59.7%) patients showed improvement and 5 deceased patients were not related to IH or the operation itself; Complications, such as vaginal adhesion, were only noted in 6.6% of patients. In addition, among 17 cases of newborns with a diagnosis of IH before birth, hymenectomy (n = 5, 29.4%) and hymenotomy (n = 9, 52.9%) were the main treatment modalities and showed improved prognosis in 52.9% of newborns. Because IH diagnosis is easy and postsurgical prognosis is good, clinicians should carefully examine every female patient at birth. IH should be considered regarding adolescent girls with abdominal pain, lower back pain, or urinary retention, and perform appropriate physical examinations of the genital introitus. In addition, accurate diagnosis as IH, not misdiagnosing as vaginal septum or agenesis, is important to prevent severe complications such as stricture and ascending infection.


Rationale
3 Describe the rationale for the review in the context of what is already known. 3 Objectives 4 Provide an explicit statement of questions being addressed with reference to participants, interventions, comparisons, outcomes, and study design (PICOS).

Protocol and registration 5
Indicate if a review protocol exists, if and where it can be accessed (e.g., Web address), and, if available, provide registration information including registration number.
N/A Eligibility criteria 6 Specify study characteristics (e.g., PICOS, length of follow-up) and report characteristics (e.g., years considered, language, publication status) used as criteria for eligibility, giving rationale.

4-5
Information sources 7 Describe all information sources (e.g., databases with dates of coverage, contact with study authors to identify additional studies) in the search and date last searched.

4-5
Search 8 Present full electronic search strategy for at least one database, including any limits used, such that it could be repeated.

4-5
Study selection 9 State the process for selecting studies (i.e., screening, eligibility, included in systematic review, and, if applicable, included in the meta-analysis).

4-5 (Figure1)
Data collection process 10 Describe method of data extraction from reports (e.g., piloted forms, independently, in duplicate) and any processes for obtaining and confirming data from investigators.

4-5
Data items 11 List and define all variables for which data were sought (e.g., PICOS, funding sources) and any assumptions and simplifications made.

Supplementary
Tables and Tables   Risk of bias in individual  studies   12 Describe methods used for assessing risk of bias of individual studies (including specification of whether this was done at the study or outcome level), and how this information is to be used in any data synthesis.
N/A Summary measures 13 State the principal summary measures (e.g., risk ratio, difference in means). N/A Synthesis of results 14 Describe the methods of handling data and combining results of studies, if done, including measures of consistency (e.g., I 2 ) for each meta-analysis.

Section/topic # Checklist item Reported on page #
Risk of bias across studies 15 Specify any assessment of risk of bias that may affect the cumulative evidence (e.g., publication bias, selective reporting within studies).

N/A
Additional analyses 16 Describe methods of additional analyses (e.g., sensitivity or subgroup analyses, meta-regression), if done, indicating which were pre-specified.

Study selection 17
Give numbers of studies screened, assessed for eligibility, and included in the review, with reasons for exclusions at each stage, ideally with a flow diagram. Study characteristics 18 For each study, present characteristics for which data were extracted (e.g., study size, PICOS, followup period) and provide the citations.
Supplementary Table 1 Risk of bias within studies 19 Present data on risk of bias of each study and, if available, any outcome level assessment (see item 12).

N/A
Results of individual studies 20 For all outcomes considered (benefits or harms), present, for each study: (a) simple summary data for each intervention group (b) effect estimates and confidence intervals, ideally with a forest plot. Tables,  Supplementary  Table   Synthesis of results  21 Present results of each meta-analysis done, including confidence intervals and measures of consistency.

5-8, Tables, Supplementary Table
Risk of bias across studies 22 Present results of any assessment of risk of bias across studies (see Item 15). Supplementary  Tables  Additional analysis  23 Give results of additional analyses, if done (e.g., sensitivity or subgroup analyses, meta-regression [see Item 16]).

Summary of evidence 24
Summarize the main findings including the strength of evidence for each main outcome; consider their relevance to key groups (e.g., healthcare providers, users, and policy makers).

8-10
Limitations 25 Discuss limitations at study and outcome level (e.g., risk of bias), and at review-level (e.g., incomplete retrieval of identified research, reporting bias).

Conclusions 26
Provide a general interpretation of the results in the context of other evidence, and implications for future research.

Funding 27
Describe sources of funding for the systematic review and other support (e.g., supply of data); role of funders for the systematic review.