Data research

The HFEA has recently launched a data research newsletter. This aims to provide information about the UK national register of fertility treatments held by the HFEA, including details on our upcoming reports and our award-winning dashboard, as well as further information on how to access data from our national UK fertility register for research purposes via the Register Research Panel (RRP). Sign up here to the newsletter Data Research Update.

What is the HFEA Register?

The Human Fertilisation and Embryology Authority (HFEA) is required by the Human Fertilisation and Embryology Act 1990 (The 1990 Act) to ensure every licensed fertility clinic in the United Kingdom (UK) submits treatment information, in order to retain oversight of the fertility sector. The HFEA holds information on fertility treatments, patients, partners, donors and children born as a result of these treatments in the UK on a secure databased known as ‘The Register’, which is believed to be the longest running database of its kind in the world.

We have collected data on all IVF and donor insemination treatments performed in the UK since 1 August 1991. In recent years this has represented nearly 100,000 cycles of treatment and storage. Summary register information can be accessed through our publications and dashboard. Cycle-level data can be made available to researchers through application to our Register Research Panel.

Over 1.9 million IVF treatment cycles undertaken between 1991 and 2022

Between 1991 and 2021, more than 390,000 live births resulted from fertility treatments

Around 52,500 patients had IVF treatment in 2022

We held our first live data research webinar on Accessing the UK fertility national register for research in February 2025. This event provided an overview of the UK’s national fertility register and how to apply for access. The recording is available below.

What data do we collect on our Register?

Clinics complete information about patients and their treatment cycles using specific forms. The types of forms, the information that we have collected, and the methods of data collection have changed over the years, so some of the data we hold is not present across all years of the Register or to the same degree of quality.

Our Register holds information about the following:

• Registration includes a record for each person involved in the treatment. This also includes demographics of patients, their partners, and donors.
• Treatment cycle and early outcomes includes a record for each treatment cycle and provides information about the cycle, including what type of cycle it is.
• Types of treatment in the Register include:
  • Donor Insemination (DI)
  • In-Vitro Fertilisation (IVF)
    • Intracytoplasmic sperm injection (ICSI)
    • Frozen embryo transfer (FET)
    • Egg freezing
    • Egg donation
    • Embryo storage
  • Where relevant, data on egg collection, egg thaw, embryo creation and use, and thaw transfer are available (e.g. the number of eggs collected, the number of embryos transferred).
• Early outcomes of IVF and DI includes data on the number of foetal pulsations and gestational sacs identified during the ultrasound scan around seven weeks after the treatment cycle.
• Outcome (for IVF and DI) includes foetal outcome, number of babies born, sex, and birthweight.
• Movement in and out of eggs/embryos/donor sperm includes a record of each movement into or out of storage of a licensed clinic for eggs, embryos and donor sperm.

It is important to note that while data on cycles using donor sperm, eggs, and/or embryos is collected on the Register, data that identifies donors on the register cannot be disclosed.

For a current list of all data fields collected on the Register please see our Data Dictionary. You can also find details about commonly requested data fields in our FAQ section below.

How does the HFEA collect the Register data?

The Register is a database, compiled by the HFEA from data submitted by licensed fertility clinics through an electronic submission system. Data is typically available two years following the initial treatment, this is due to requirements on submitting outcome information from the clinics and the time required to complete data validation exercises.

How is consent collected?

Following the amendment of the Human Fertilisation and Embryology Act 1990, since 1 October 2009 patients have been given a consent form to choose whether they agree to allow personal information about themselves, and any child(ren) born as a result of the treatment, to be disclosed for research purposes. Patients can choose the personal information about the child(ren) to be handled differently.

The 2010 Regulations provided retrospective changes prior to 2009 to allow the use of register data in research. Patients were informed that they could opt-out of having their data used in research if they received treatment prior to 1 October 2009.

The national data opt-out is a policy that allows individuals to opt out of their confidential patient information being used for research and planning purposes. It does not apply in situations where the participant has given explicit consent for use of their data. This includes where the HFEA asks for patient’s consent to use personal information held in the Register for research purposes. However, the policy may apply if researchers plan to link to third party datasets.

Find out more about how we manage patient’s information.

Find out more about our Privacy Policy.

What about patient confidentiality?

Research can only take place within the strict confines of the laws, which provides very strong protection of patient, donor, and offspring confidentiality. Researchers must ensure anyone who has access to personal data understands their responsibilities for confidentiality, data protection and information security and is left in no doubt about the consequences of misconduct. Researchers must also certify that their organisation has met information governance requirements.

Any disclosure, even inadvertent or indirect, of an individual’s information that’s contained on our Register is a criminal offence outlined in the 1990 Act.

How can I obtain Register data?

There are two ways to access cycle-based Register data depending on the identifiability of the information.

1. Anonymised register data

The anonymised datasets which contain data on all treatment cycles between 1991 and 2018 are outlined below. For further information, please see the Guide to the Anonymised Register.

The data in the anonymised register has been stripped of direct identifiers of patients and any children born as a result of treatment, and uses techniques such as suppression, offsetting and aggregation.

Please note, we are currently reviewing our anonymised register datasets to ensure consistency with our other publications. This follows from large-scale data migration work which has led to improvements in data quality. Should you require access to the datasets please contact register.research@hfea.gov.uk.

Anonymised register data for 2017 - 2018

Anonymised register data for 2015 - 2016

Anonymised register data for 2010 - 2014

Anonymised register data for 2005 - 2009

Anonymised register data for 2000 - 2004

Anonymised register data for 1995 - 1999

Anonymised register data for 1991 - 1994

See publications using the anonymised Register data.

2. Project-specific data via application to the Register Research Panel

Use of either de-personalised or personally identifiable data will require an approval of the project from the HFEA Register Research Panel (RRP) and a favourable opinion from a Health Research Authority (HRA) established or recognised Research Ethics Committee (see Sections 6 of the application form).

De-personalised or de-identified data is stripped of direct identifiers, and cannot be easily linked to a specific person, but contains some fields which could be used to indirectly identify an individual through combinations of information by the people handling the data (e.g. sex, month and year of birth, date of embryo transfers, geographies or other personal characteristics). The data will be released with controls in line with the ICO Anonymisation Code of Practice.

The data request may include direct identifiers (e.g. name, NHS number, date of birth). This may be necessary if a research project involves linking the Register dataset with other datasets, such as NHS health records. To access identifiable data, an existing legal gateway must be presented (see Section 5 of the application form). The direct identifiers are usually only used to link to other approved datasets by a data processor, and only data stripped of direct identifiers is transferred to researchers.

The datasets created by the HFEA are usually cycle-based but can be individual-based which include records of patients with multiple cycles.

To ensure patient confidentiality and safe research access to our data a legally-binding data sharing agreement needs to be in place before the project starts.

As indicated in “How is consent collected?”, personal information of patients and partners who did not provided their consents for disclosing data for research purpose will not be released.

See publications from the RRP approved projects below.

What is the Register Research Panel?

The Register Research Panel (RRP) is a committee run every two months by the HFEA. They make decisions on whether to grant or refuse applications from researchers to access data from the HFEA Register for research purposes.

All decisions made by the RRP are prescribed by the Human Fertilisation and Embryology (Disclosure of Information for Research Purposes) Regulations 2010 (2010 Regulations), which sets out when the HFEA may grant a request from a research establishment to process disclosable protected information. The Authority also receive annual updates about the approved research projects, to stay up-to-date on the ongoing research being carried out using Register data. Where changes are required to a research project, such as project renewals or a change in team members, researchers must submit requests for amendments to the RRP for approval.

How do I apply to the RRP?

If you are part of a UK-based research establishment (such as a university, other body or institution carrying out medical or other research), are interested in accessing project-specific cycle-level data from the HFEA Register to use in your research, and you feel that your project is in the interests of the public and/or improving patient care and services, then you can contact us and start an application to the RRP.

1. Contact us via RRP research enquiry form to discuss your research project idea using HFEA Register data and the data you wish to have access to before you complete the application form. Not all enquiries need to progress to the formal application stage, for example it may be that your requirement can be satisfied through existing published data. Please include the following information in your enquiry:
   • Your name
   • Name of your research establishment
   • A brief description of your project including research aims and objectives
   • Data you are interested in
   • Nature of the advice you are seeking
2. Complete the RRP application form and data specification sheet. If you have any questions during the application process, please refer to the FAQ section below or email register.research@hfea.gov.uk.
   On average it takes a minimum of 5 months to release data after a full approval at a RRP meeting. If further information is required or an application is conditionally approved additional 4 months likely to be added. Therefore, it is important to provide all the information necessary for the application with clear justification for the study and each of the data fields you wish to have access.
3. Send the following documents to register.research@hfea.gov.uk.
   • A signed and completed RRP application form
   • Data specification sheet
   • A CV of the Chief Investigator
   • Any other documents referred to in the completed application
4. Your application will be processed, and we will confirm that we have received all required evidence to commence assessment of your application against the approval standards. We may request that you make some amendments or provide additional supplementary information before your application is ready to be considered by the RRP. Examples of this might include:
   • Recommendations to add more details if the information provided is unclear
   • Recommendations on changes to the data specification sheet, to ensure you will have the most valuable data to answer your research question

4. A favourable opinion from a HRA established or recognised Research Ethics Committee (REC) is required (see Section 6 of the application form). Once you have had confirmation from the HFEA team that the Register holds the data you are requesting, and that it would be available to access through the RRP, then you should submit a REC application through the HRA’s Integrated Research Application System (IRAS). It is not necessary to have received a favourable opinion from the REC by the time your project proposal is considered by the RRP, but an application to REC should have been submitted by the time of application to RRP.
5. Completed applications will be added to the agenda of the next available RRP meeting, with the panel functioning on a first come first serve basis (at the time of final submission). The team will let you know the date of the meeting your project will be considered at. Unfortunately, it is not guaranteed that the application will be added to the closest calendar meeting as there is limited availability on each agenda, but the team will aim to do so wherever possible. The panel will make one of the following decisions:
   • Approve the application
   • Conditionally approve the application
     • For example, in circumstances where you are awaiting an opinion from REC, the RRP may grant approval conditional on receiving a favourable opinion from REC, and no data will be released until those documents have been received.
       Usually up to 56 days will be given to address the conditions.
   • Seek further clarification
     • The panel may require additional clarification on a few specific areas before they are able to make their final decision. As an example, this may be a request for additional justification on a specific data field, or it may be to confirm security arrangements.
     • Where clarification is sought, you have 56 days to submit additional information before your application is automatically refused. Wherever possible we will support you in providing this information to allow your project to be considered again at the next RRP meeting.
   • Reject the application
     • The panel will lay out their concerns and give indications of where improvements should be made for you to submit a new application in the future.
6. We aim to send a letter regarding the decision within 20 working days of the RRP meeting, however for more complex outcomes, such as detailed requests for clarification, this may take longer.

What happens after our project is approved by the RRP?

After you have received notice that your application has been approved by the RRP, the team will get in touch to discuss your data authorisation. This will form a legally-binding contract laying out exactly what data you will receive, and your obligations in line with our regulations.

Additionally, if you will be using one or more third parties to carry out data linkage, we will also use this time to create data sharing/processing agreements for all parties to sign.

Once these agreements have been signed, we will require payment of £5,000 prior to creating your bespoke dataset. After payment has been received, we will prepare and send you the encrypted dataset described in your data authorisation within 90 days.

While your research project is ongoing you should consider the following:

• You will be required by the 2010 Regulations to submit an annual report to update the RRP on the progress of your report.
• Any amendments to your research project, including but not limited to those listed below, will need to be considered and approved by the RRP. Please contact us and submit the Register Research Project Change Form for:
  
  • Change in organisation or chief investigator
  • New variables requested for an existing data set (may incur a fee)
  • Change in research aims
  • Substantial change in collaborators (the staff members in the research team who have access to the Register data)
  • More recent data requested (may incur a fee)
  • Another amendment which is not specified above

When your research project comes to an end, and/or your data authorisation from the HFEA has expired, you are required to destroy all data, and provide proof of data destruction to the RRP.

If you wish to continue to access the data after the current authorisation period, please contact us and submit the Register Research Project Renewal Form and submit to register.research@hfea.gov.uk.

Ongoing research projects approved by RRP

• Predict IVF outcomes using advanced machine learning techniques
  Chief investigator: Floriane Moy
  Research establishment: Gaia Ltd.
• The impact of duration of freezing of IVF embryos on pregnancy and perinatal outcomes – analysis of U.K. national data
  Chief investigator: Edwin Amalraj Raja
  Research establishment: University of Aberdeen
• General Health Outcomes in Subfertile Men: a UK register-based cohort study
  Chief investigator: Alastair Sutcliffe
  Research establishment: University College London
• Associations between Assisted Reproductive Technologies and Women's Mental Health: an investigation using clinical data linkage
  Chief investigator: Lauren Carson and Robert Stewart
  Research establishment: South London and Maudsley NHS Trust
• Effects of Assisted Reproductive Technology (ART) on long-term Birth Weight trends: A National Cohort Study
  Chief investigator: Stephen Roberts
  Research establishment: University of Manchester
• Environmental determinants of IVF treatment
  Chief investigator: Tom Clemens
  Research establishment: University of Edinburgh
• Educational outcomes in children born after assisted reproductive technology: a population-based linkage study
  Chief investigator: Alastair Sutcliffe
  Research establishment: University College London
• Prolonged effects of assisted reproductive technologies on health of women and their children: a record linkage study for England (PEARL)
  Chief investigator: Claire Carson
  Research establishment: University of Oxford
• General health and hospital admissions in children born after ART: a population based linkage study
  Chief investigator: Alastair Sutcliffe
  Research establishment: University College London
• Development and validation of prognostic models to predict pregnancy outcomes following in-vitro fertilization (IVF) treatment
  Chief investigator: David J McLernon
  Research establishment: University of Aberdeen

Completed research projects approved by RRP

• Perinatal outcomes of singletons born following in-vitro fertilisation: a comparison of different embryo transfer strategies using UK data
  David J McLernon, University of Aberdeen
• Live birth predication model over multiple IVF cycles
  Ines de Santiago, University of Cambridge
• Ethnic variation in fresh and frozen embryo transfer outcomes
  Mariano Mascarenas, Leeds Teaching Hospitals NHS Trust
• Cancer risk in children born after IVF/ICSI
  Alastair Sutcliffe, University College London
• Cancer risk and mortality in women after IVF
  Alastair Sutcliffe, University College London
• Effect of ethnicity on the success of assisted reproduction technologies
  Walid Maalouf, University of Nottingham
• EpiHealth Outcomes Project: The effect of maternal age, embryo cryopreservation and culture on perinatal outcomes and child health
  Daniel Brison, Central Manchester University Hospitals NHS Foundation Trust

What research has been done using data from the HFEA Register?

We rely on researchers to let us know when they have published research using our datasets. If you have a publication to contribute to the bibliography below, please contact us at register.research@hfea.gov.uk.

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