UMIN-ICDS Clinical Trial

Public title

Transrectal Oocyte Retrieval as an Alternative When Transvaginal Oocyte Retrieval Is Difficult or Not Acceptable

Acronym

TROR Study

Scientific Title

A Study of Transrectal Ultrasound-Guided Oocyte Retrieval in Patients for Whom Transvaginal Oocyte Retrieval Is Not Feasible or Acceptable

Scientific Title:Acronym

TROR Study

Region

Japan

Condition

Female infertility

Classification by specialty

Obstetrics and Gynecology

Classification by malignancy

Others

Genomic information

NO

Narrative objectives1

In recent years, the population of patients requiring fertility preservation has expanded to include adolescents and young adults (AYAs) with cancer, transgender and gender-diverse individuals, and patients with congenital vaginal agenesis. Accordingly, there is a growing need to establish alternative oocyte retrieval techniques for patients in whom transvaginal oocyte retrieval (TVOR) is difficult or not feasible. Transrectal oocyte retrieval (TROR), like TVOR, allows access to the ovaries from the vicinity of the ovaries and is therefore expected to achieve greater oocyte retrieval efficiency than the transabdominal approach. Although the safety and efficacy of TROR have been reported in other countries, no data are currently available in the Japanese population. This study is the first to introduce TROR in Japan and aims to evaluate its safety and feasibility.

Basic objectives2

Safety,Efficacy

Basic objectives -Others

Trial characteristics_1

Trial characteristics_2

Pragmatic

Developmental phase

Primary outcomes

Number of oocytes retrieved
Number of oocytes cryopreserved
Incidence of intraoperative and postoperative complications

Key secondary outcomes

Number of MII oocytes
Oocyte retrieval time
Postoperative pain
Adverse events, including postoperative infection and bleeding
Anti-Mullerian hormone level
Dose of medications administered

Study type

Interventional

Basic design

Single arm

Randomization

Non-randomized

Randomization unit

Blinding

Open -no one is blinded

Control

Uncontrolled

Stratification

Dynamic allocation

Institution consideration

Blocking

Concealment

No. of arms

1

Purpose of intervention

Treatment

Type of intervention

Maneuver

Interventions/Control_1

Transrectal Oocyte Retrieval
bowel preparation
antibiotic prophylaxis

Interventions/Control_2

Interventions/Control_3

Interventions/Control_4

Interventions/Control_5

Interventions/Control_6

Interventions/Control_7

Interventions/Control_8

Interventions/Control_9

Interventions/Control_10

Age-lower limit

16

years-old

<=

Age-upper limit

Not applicable

Gender

Female

Key inclusion criteria

1. Women who wish to undergo oocyte retrieval for the purpose of fertility preservation or assisted reproductive technology.
2. Patients who wish to preserve the hymen, or in whom transvaginal oocyte retrieval is considered difficult for anatomical or medical reasons.
3. Patients who have received sufficient explanation regarding the study and have provided written informed consent voluntarily.

Key exclusion criteria

1. Patients with active rectal or anal disease, such as proctitis, perianal abscess, or severe hemorrhoids.
2. Patients with pelvic or systemic infection.
3. Patients with a bleeding tendency or those receiving anticoagulant therapy in whom safe needle puncture is considered difficult.
4. Patients in whom insertion of a transrectal ultrasound probe is considered difficult.
5. Patients whom the principal investigator considers unsuitable for participation in the study.

Target sample size

5

Name of lead principal investigator

1st name	Yasushi
Middle name
Last name	Takai

Organization

Saitama Medical Center

Division name

Department of Obstetrics and Gynecology

Zip code

350-0844

Address

Kamoda 1981, Kawagoe City, Saitama Prefecture

TEL

049-228-3681

Email

yastakai@saitama-med.ac.jp

Name of contact person

1st name	Yasunari
Middle name
Last name	Nomoto

Organization

Saitama Medical Center

Division name

Center for Maternal-Fetal and Neonatal Medicine (Maternal and fetal division)

Zip code

350-0844

Address

Kamoda 1981, Kawagoe City, Saitama Prefecture

TEL

049-228-3681

Homepage URL

Email

nomotoya@saitama-med.ac.jp

Institute

Saitama Medical Center Department of Obstetrics and Gynecology

Institute

Department

Personal name

Organization

Self-funding

Organization

Division

Category of Funding Organization

Self funding

Nationality of Funding Organization

Co-sponsor

Name of secondary funder(s)

Organization

Saitama Medical Center, Institutional Review Board (IRB)

Address

Kamoda 1981, Kawagoe City, Saitama Prefecture

Tel

049-228-3902

Email

smcrinri@saitama-med.ac.jp

Secondary IDs

NO

Study ID_1

Org. issuing International ID_1

Study ID_2

Org. issuing International ID_2

IND to MHLW

Institutions

埼玉医科大学総合医療センター(埼玉県)　Saitama Medical Center（Saitama Prefecture）

Date of disclosure of the study information

2026

Year

10

Month

01

Day

URL releasing protocol

Publication of results

Unpublished

URL related to results and publications

Number of participants that the trial has enrolled

Results

Results date posted

Results Delayed

Results Delay Reason

Date of the first journal publication of results

Baseline Characteristics

Participant flow

Adverse events

Outcome measures

Plan to share IPD

IPD sharing Plan description

Recruitment status

Preinitiation

Date of protocol fixation

2026

Year

10

Month

01

Day

Date of IRB

Anticipated trial start date

2026

Year

10

Month

01

Day

Last follow-up date

2030

Year

12

Month

31

Day

Date of closure to data entry

Date trial data considered complete

Date analysis concluded

Other related information

Registered date

2026

Year

09

Month

29

Day

Last modified on

2026

Year

09

Month

29

Day

Link to view the page

Value
https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000072240