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Our data

We collect data and statistics about the fertility treatment cycles performed each year in the UK. We use this data to improve patient care and help researchers to conduct world-class research, whilst ensuring very strong protection of patient, donor and offspring confidentiality. This page explains more.

Why do we collect data?

By law, clinics have a duty to submit data to us about fertility treatments taking place and babies born as a result. We hold this data on a secure database known as ‘The Register’, which is the longest running database of its kind in the world

Clinics have a legal obligation to submit this data to us because it allows us to:

  • retain oversight of what’s happening in the fertility sector
  • look for trends and where improvements can be made
  • ensure we can make decisions based on the latest evidence
  • publish reports of interest to the public and to drive improvements in the sector
  • make data available to researchers conducting important research.

Anonymised Register

To allow researchers to make good use of the data we collect, we publish an anonymised version of the Register. The anonymised Register allows researchers to access a large and rich data set, but one that does not identify any patients, or children born as a result of treatment.

Research using anonymised data can still answer important questions, like which factors influence treatment outcomes, or which factors indicate that a patient should have only one or two embryos transferred during treatment.

Find out more about the anonymised Register and how to make the most of it.

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

What research has been completed using our data?

World-class research has been carried out using our data, either alone or by linking to other datasets.

Studies have gone on to inform academic and public debate into assisted reproduction and factors affecting outcomes.

The below examples show the wide range of research topics using our data.

  • Predicting the success of IVF
    The University of Aberdeen and the Erasmus MC-University Medical Centre in the Netherlands used our data to create a calculator to help predict the likelihood of a successful cycle of IVF based on certain factors. Further details can be found at ‘Online calculator that tries to predict IVF success released’.
  • Assessing the risk of childhood cancer
    A collaboration between researchers at UCL, University of Oxford and University of Edinburgh linked our data with the National Registry of Childhood Tumours to assess the cancer risk among children born after assisted reproduction. They found that there is no increased risk in cancer for children born from IVF. Further details can be found at ‘Cancer Risk among Children Born after Assisted Conception’.
  • Assessing the safety of pre-implantation Genetic Testing for Monogenic disorders (PGT-M)
    Researchers used the anonymised Register to assess the safety of pre-implantation Genetic Testing for Monogenic disorders (PGT-M), a treatment which involves checking the genes or chromosomes of embryos for a specific genetic condition before IVF takes place to avoid passing it onto any resulting child. The researchers concluded that PGT-M is a safe procedure. Further details can be found at ‘Reproductive outcome following pre-implantation genetic diagnosis (PGD) in the UK’.
  • Examining the link between ovarian stimulation and miscarriage
    The anonymous Register was used by researchers to assess the relationship between the response women had to ovarian stimulation and miscarriage following IVF. They found a strong association between the number of eggs collected and the rate of miscarriage, with the miscarriage rate falling from 20% to 13% when an increased number of eggs was collected before levelling off. Further details can be found at ‘Association between response to ovarian stimulation and miscarriage following IVF: an analysis of 124 351 IVF pregnancies’.

If you are currently carrying out research using our data, we are keen to hear how you get on. Please email to let us know of your progress.

What about patient confidentiality?

Research can only take place within the strict confines of the law, which provides very strong protection of patient, donor and offspring confidentiality (stronger still than normal medical confidentiality).

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

I’m a researcher, how can I apply to use your data?

Researchers who intend to use data in our Register only and not link to other datasets can use our anonymised version of the data in our Register. This anonymised data contains a large proportion of all the Register data going back to 1991, with the patient identifiers removed.

If the anonymised Register is not useful for your intended project, or you intend to undertake research linking the Register with another dataset, you’ll need to contact us directly for further information about the process and legal requirements. Should you wish to contact us with ideas for research or to discuss potential future projects, please email

In accordance with the Human Fertilisation and Embryology (Disclosure of Information for Research Purposes) Regulations 2010, a fee of £5,000 will be charged to cover the cost of extracting data from the Register and preparing the information for disclosure. There may be additional charges to cover any required legal costs.

Our data dictionary

Our data dictionary sets out the definitions and characteristics of each piece of data and how they are validated.

Download the data dictionary

Review date: 24 August 2024