Condition category
Urological and Genital Diseases
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status

Plain English Summary

Background and study aims
Infertility is when a couple cannot get pregnant (conceive), despite having regular unprotected sex. The underlying cause of infertility is unclear in most men who suffer from the condition. The aim of this study is to find out whether male infertility can be caused by particular changes in DNA (the genetic material) and by unusual levels of reproductive hormones.

Who can participate?
Infertile men aged 18-65.

What does the study involve?
Participants are asked to complete a questionnaire and undergo blood sampling and clinical examination. A semen sample is also tested. Some participants have testicular biopsies (tissue samples from the testicles) as part of their treatment for infertility and a small amount of testicular tissue is stored. Participants are followed up over the telephone by a study investigator (clinician or nurse) on up to two occasions during the 3 years after the study.

What are the possible benefits and risks of participating?
The results of this study will advance the understanding of infertility in men, and may improve diagnostic methods and treatments for couples affected by infertility in the future. The results of the tests performed during this study could lead to incidental findings which are likely to require further medical assessment. In this case, participants are referred for the appropriate medical care that would be offered to an NHS patient. Some participants may experience pain or mild discomfort from giving a blood sample which involves inserting a needle into their arm to take blood. However, blood samples are collected by a trained member of the research team who is experienced in taking blood. All information and results from the study are kept strictly confidential and only used by researchers involved in the study.

Where is the study run from?
Imperial College Healthcare NHS Trust (UK)

When is the study starting and how long is it expected to run for?
July 2014 to March 2023

Who is funding the study?
Imperial College Trust (UK)

Who is the main contact?
Dr Channa N. Jayasena

Trial website

Contact information



Primary contact

Dr Channa Jayasena


Contact details

Imperial College London
6th Floor Commonwealth Building
Hammersmith Hospital
Du Cane Road
W2 0NN
United Kingdom
+44 (0)208 383 3242

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Investigating the regulation of male fertility: an observational cohort study


Study hypothesis

The study aims to identify factors that may be causing male infertility. These factors will provide better understanding of male infertility and its underlying pathophysiology.

Ethics approval

West London Research & Gene Therapy Advisory Committee, 15/07/2014, ref: 14/LO/1038

Study design

Observational cohort study.

Primary study design


Secondary study design

Cohort study

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details to request a patient information sheet


Male infertility


Patients will be recruited via the Andrology department at Hammersmith Hospital, London. The aim is to recruit approximately 2000 men. Participants will be asked to complete a questionnaire, undergo blood sampling and clinical examination. A semen sample will also be analysed. Some participants have testicular biopsies as part of their treatment for infertility and a small amount of testicular tissue will be stored. Data will be processed statistically and used to highlight the key mechanisms underlying male infertility. Participants will be followed up over the telephone by a study investigator (clinician or nurse), on up to two occasions during the 3 years following study recruitment.

Intervention type



Drug names

Primary outcome measure

Genetic/molecular abnormalities, assessed using state-of-the-art techniques at the time including Sanger sequencing, next generation sequencing, array comparative genomic hybridisation (CGH), polymerase chain reaction (PCR) and enzyme assays and/or immunoassays, at baseline

Secondary outcome measures

1. Sperm parameters, measured using routine semen analysis at baseline
2. Smoking status, measured using a questionnaire at baseline
3. Weight, measured using scales at baseline
4. Sperm count abnormalities, measured using routine semen analysis at baseline

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Infertile men
2. 18-65 years of age

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. History of anaemia
2. Needle phobia
3. Impaired ability to provide full consent to take part in the study

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Imperial College Healthcare NHS Trust
W12 0HS
United Kingdom

Sponsor information


AHSC Joint Research Compliance Office

Sponsor details

510A 5th Floor Lab Block
Charing Cross Hospital
Fulham Palace Road
W6 8RF
United Kingdom

Sponsor type

Research organisation



Funder type


Funder name

Imperial College Trust (ref: P52570)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

The planned publication date is approximately one year after the trial end date in a high-impact peer reviewed journal.

IPD sharing plans
The current data sharing plans for the current study are unknown and will be made available at a later date.

Intention to publish date


Participant level data

To be made available at a later date

Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes

05/05/2020: Due to current public health guidance, recruitment for this study has been paused. 14/08/2019: The following changes were made to the trial record: 1. The recruitment end date was changed from 14/07/2019 to 31/12/2022. 2. The overall trial end date was changed from 14/07/2019 to 01/03/2023. 3. The intention to publish date was changed from 14/07/2020 to 01/03/2024.