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Active, not recruitingNCT07030218FLAG-VSUpdated Jun 30, 2026

A Warning Red Flag Classification System to Predict Risk of Vasovagal Event During Office Hysteroscopy

An observational study in Vasovagal Syncope (VVS) and Presyncope, sponsored by Tanvir Hospital. Active, not recruiting at 1 site in India. Open to female participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-06-30.

Sponsored by Tanvir Hospital · Observational

Study type
Observational
Model
Case-only
Time perspective
Prospective
Enrollment
100
Ages
18 Years and older
Sex
Female
01

Study summary

The goal of this pilot cross sectional study is to identify participants at risk of vasovagal reaction/syncope(VVR/VVS) during office hysteroscopy. A predictive red flag classification system is being studied to improve procedural safety during office hysteroscopy. Researchers will perform office hysteroscopy as per the standard protocol by vaginoscopic technique. A nurse positioned at the head side of the participant will record signs and symptoms of VVR/VVS. The participant will be asked of the severity of the pain experienced during office hysteroscopy in relation to their menstrual cycle. The procedure will be discontinued at any point the participant wishes to stop.

Read the detailed description

Office hysteroscopy is increasingly utilized due to advancements in instrumentation and techniques; however, its adoption in routine gynecologic practice remains limited to 10-12% of cases. This under utilization is largely attributed to the perception of pain and lack of financial incentives. Consequently, fewer than 20% of gynecologists employ office hysteroscopy for the evaluation of intrauterine pathology.

Although generally safe, vasovagal syncope (VVS) is the most concerning complication, with a reported prevalence ranging from 0.21% to 1.85%. Other complications include pain, infection, and bleeding. Surgeons often fail to anticipate vasovagal responses during the procedure. This study aims to develop a red flag classification system based on pain response to enable early recognition and prevention of VVS during office hysteroscopy.

Research design This is a single center, prospective observational pilot study enrolling women undergoing office hysteroscopy over 10 months.

Sample Size Calculation As this is a pilot feasibility study, a formal power calculation for hypothesis testing was not applicable. Sample size was determined using a precision-based approach. Based on a published vasovagal event rate of 6.5 % during office hysteroscopy, we estimated that 100 participants would be required to estimate this proportion with a 95% confidence interval and a margin of error of ±5%, using the Wilson score method. No formal stopping rules or interim analyses were pre-specified, consistent with the pilot and exploratory nature of this study.

Statistical Analysis Descriptive analysis will be conducted for continuous and categorical variables. Chi-square tests will evaluate the association between pain classification and vasovagal events. The STROBE checklist will guide reporting.

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Conditions studied

  • Vasovagal Syncope (VVS)
  • Presyncope

Keywords

  • vasovagal syncope
  • hysteroscopy
  • red flag classification
  • presyncope
03

Who can participate

Ages eligible
18 Years and older
Sexes eligible
Female
Accepts healthy volunteers
Yes
Sampling method
Non-probability sample

Study population

women undergoing office hysteroscopy in the hospital / outpatient

Inclusion criteria

  • Women ≥18 years
  • Prior gynecological care
  • Informed consent provided

Exclusion criteria

Exclusion Criteria:

  • Inability to consent
  • Psychiatric disorders or anxiolytic use
  • Use of dilators or anesthesia above level 3a
  • Family history of VVS
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Study design

Observational model
Case-only
Time perspective
Prospective
Enrollment
100 participants (estimated)
Patient registry
No

Interventions

  • ProcedureOffice hysteroscopy

    In office hysteroscopy will utilize 1.9-2.9 mm hysteroscopes (primarily Bettocchi) by the technique of vaginoscopy, without anesthesia or up to level 3a analgesia, in accordance with International Consensus Statement for Recommended Terminology Describing Hysteroscopic Procedures. The choice of distension medium and hysteroscope is left to the operator's discretion. A nurse positioned at the head of the patient will record signs and symptoms of VVR/VVS.

05

What researchers measure

Primary outcomes

  1. To evaluate the feasibility of a predictive red flag classification system for identifying patients at risk of vasovagal syncope during office hysteroscopy(OH), with the goal of enhancing procedural safety.

    During OH, a nurse positioned at the head of the patient will measure and record the tolerance level of the patient at the completion of the procedure using the Red flag Classification: Level Description Classification 0 Pain ≤ normal menstruation (Well tolerated) Green Flag 1. Pain \> menstruation, no signs of distress (Tolerated) Green Flag 2. Level 1 + objective signs (sweating, pallor, malaise) (Tolerated)Red Flag 3. Level 2 + facial pallor ± loss of consciousness (Not tolerated) Red Flag Normal menstruation is when the pain during periods does not interfere with daily activities. The level of pain tolerated by the women in relation to the menstruation. The feasibility will be assessed by 1) the checking the nurses records which capture the pain scores for any delays or missing data, 2 ) the number of post- procedural pain and tolerance score recorded by the nurse, 3) time taken to complete data 4)Completeness of the data. This information will be used to refine the protocol.

    Time frame: The tolerance level will be assessed perioperative/periprocedural, i.e from the initiation of OH procedure until the completion of the OH procedure.

Secondary outcomes

  1. To assess the potential barriers in implementing the red flag classification system, as preparation for a future large-scale validation study

    The potential barriers are assessed by 1) reviewing the recruitment rate versus the target sample size, 2 ) drop out rate, 3 ) nurses feedback on the ease of recording the tolerance classification, 4) Patient's understanding of the classification and their acceptability to report pain.

    Time frame: The tolerance level will be assessed perioperative/periprocedural, i.e from the initiation of OH procedure until the completion of the OH procedure.

Other outcomes

  1. To measure visual analogue score for pain post procedure separately from the tolerance score.

    The visual analogue score for pain is described as - zero which is equivalent to no pain and 10 is the worst possible pain

    Time frame: The visual analogue score of pain will be assessed postoperative/postprocedural, i.e immediately after the completion of the OH procedure.

  2. To measure the body mass index of participant undergoing office hysteroscopy

    To measure the weight in kilograms, height in meters, which will be combined to report body mass index (BMI) in kg/m\^2)

    Time frame: BMI is calculated when the participant is enrolled in the study to perform office hysteroscopy.

06

Study locations

1 site
  • Tanvir Hospital
    Hyderabad, Telangana 500073, India
07

References and documents

Publications

  • Viechtbauer W, Smits L, Kotz D, Bude L, Spigt M, Serroyen J, Crutzen R. A simple formula for the calculation of sample size in pilot studies. J Clin Epidemiol. 2015 Nov;68(11):1375-9. doi: 10.1016/j.jclinepi.2015.04.014. Epub 2015 Jun 6. PubMed 26146089 ↗
  • Ubeda A, Cabrera S, Escales C, Funes B, Martinez M, Puche A, Martinez Garcia S. Predictors of vasovagal symptoms or syncope during outpatient diagnostic hysteroscopy: A prospective observational study. Eur J Obstet Gynecol Reprod Biol. 2025 May;309:121-125. doi: 10.1016/j.ejogrb.2025.03.044. Epub 2025 Mar 20. PubMed 40121697 ↗
  • Munro MG, Kasiewicz JL, Desai VB. Office versus Institutional Operative Hysteroscopy: An Economic Model. J Minim Invasive Gynecol. 2022 Apr;29(4):535-548. doi: 10.1016/j.jmig.2021.12.008. Epub 2021 Dec 18. PubMed 34933096 ↗
  • Isaacson K. Office hysteroscopy: a valuable but under-utilized technique. Curr Opin Obstet Gynecol. 2002 Aug;14(4):381-5. doi: 10.1097/00001703-200208000-00004. PubMed 12151827 ↗

Study documents

  • Protocol and statistical analysis plan · Jun 25, 2026
  • Informed consent form · Jun 13, 2025

Documents are hosted by the registry — open the source record to download them.

Individual participant data

Plan to share: Yes — all individual participant data (IPD) that underlie results in a publication

Supporting information: Study protocol, Sap, Icf, Csr

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Registry details

Key details

Study ID
NCT07030218
Lead sponsor
Tanvir Hospital
Responsible party
Tanvir Singh (Dr, Tanvir Hospital) — Principal investigator
First posted
Jun 22, 2025
Start date
Jun 20, 2025
Primary completion
Jul 10, 2026 (estimated)
Completion
Jul 12, 2026 (estimated)
Last update
Jun 30, 2026

Study contacts

Tanvir Dr.
principal investigator · Tanvir Hospital

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is active, not recruiting, as verified in Jul 2025. You cannot join it, but the record below documents what was studied.

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