Asked by: Lord Winston (Labour - Life peer)
Question to the Department of Health and Social Care:
To ask His Majesty's Government, of the human eggs which were harvested and frozen by vitrification from 2014-24 for social purposes, how many (1) did not thaw satisfactorily or were considered unsuitable for an attempt at fertilisation, (2) of those thawed underwent attempts at fertilisation with or without intracytoplasmic sperm injection, and (3) of those fertilised produced viable embryos suitable for uterine transfer.
Answered by Baroness Merron - Parliamentary Under-Secretary (Department of Health and Social Care)
The information is not held in the format requested. The Human Fertilisation and Embryology Authority (HFEA) has advised that it does not hold information on the method of freezing for the whole period requested, the reasons the eggs were frozen, or how many eggs did not thaw satisfactorily or were considered unsuitable and how many of the eggs thawed underwent attempts at fertilisation. The following table shows the number eggs fertilised, the number of embryos created, and the number of embryos transferred from 2014 to 2023:
Eggs fertilised | 29,029 |
Embryos created | 18,498 |
Embryos transferred | 2,949 |
Data is as recorded by the HFEA on 17 December 2025 and reflects the data on this date and therefore may change over time.
Asked by: Lord Winston (Labour - Life peer)
Question to the Department of Health and Social Care:
To ask His Majesty's Government how many women having uterine transfer of one or more embryo(s) produced from frozen oocytes after thawing had a positive pregnancy test between 2014-24; and how many of these pregnancies resulted in a spontaneous abortion (1) before 12 weeks of gestation, and (2) after 13 weeks of gestation.
Answered by Baroness Merron - Parliamentary Under-Secretary (Department of Health and Social Care)
The information is not available in the format requested. The Human Fertilisation and Embryology Authority (HFEA) holds information on the number of pregnancies, interpreted as instances where one of more foetal heart pulsation was recorded, and records of total numbers of miscarriages, not by weeks, from 2014 to 2023 which is shown in the following table:
Pregnancies | 609 |
Miscarriages | 93 |
The data is as shown on the HFEA’s register database on 17 December 2025. This is a live database so these figures reflect the data on this day and are likely to change over time. This reflects time needed for clinics to submit data and undergo validation as stated on the HFEA register. Data shown includes only treatments using patients own thawed eggs.
Asked by: Lord Winston (Labour - Life peer)
Question to the Department of Health and Social Care:
To ask His Majesty's Government how many embryos derived from frozen eggs were transferred to the uterus for the purpose of producing a baby between 2014-24.
Answered by Baroness Merron - Parliamentary Under-Secretary (Department of Health and Social Care)
Information is not available in the format requested. The Human Fertilisation and Embryology Authority (HFEA) has provided information on the total number of embryos transferred from patients’ own thawed eggs for the period 2014 to 2023, rather than a subset of eggs stored, which is shown in the following table:
Embryos transferred | 2,949 |
The data is as shown on the HFEA’s register database on 17 December 2025. This is a live database so these figures reflect the data on this day and are likely to change over time. This reflects time needed for clinics to submit data and undergo validation as stated on the HFEA register. Data shown includes only treatments using patients own thawed eggs.
Asked by: Lord Winston (Labour - Life peer)
Question to the Department of Health and Social Care:
To ask His Majesty's Government how many women in the UK had their oocytes frozen for social purposes in (1) 2015, (2) 2016, (3) 2017, (4) 2018, (5) 2019, (6) 2020, (7) 2021, (8) 2022, (9) 2023, (10) 2024, and (11) 2025.
Answered by Baroness Merron - Parliamentary Under-Secretary (Department of Health and Social Care)
The Human Fertilisation and Embryology Authority (HFEA) does not hold information on the reasons eggs were frozen. Data from 2015 to 2023 is available on the number of patients undergoing egg freezing cycles per year, without the reasons the eggs were frozen, and are as follows: 1,020 in 2015; 1,165 in 2016; 1,365 in 2017; 1,755 in 2018; 2,130 in 2019; 2,030 in 2020; 3,400 in 2021; 3,910 in 2022; and 5,515 in 2023. This information is from the HFEA Register.
Asked by: Lord Winston (Labour - Life peer)
Question to the Department of Health and Social Care:
To ask His Majesty's Government how many women in the UK whose eggs were frozen before they reached the age of 35 years subsequently had a live birth after these egg(s) were thawed, fertilised and transferred to the uterus.
Answered by Baroness Merron - Parliamentary Under-Secretary (Department of Health and Social Care)
The information is not available. The Human Fertilisation and Embryology Authority (HFEA) has advised that it cannot provide the information as requested due to how the data is stored on the HFEA Register.
Work is currently ongoing so that this information can be provided over the next 12 to 18 months.
Asked by: Lord Winston (Labour - Life peer)
Question to the Department of Health and Social Care:
To ask His Majesty's Government how many women in the UK whose eggs were frozen after the age of 35 subsequently had a live birth after their egg(s) had been thawed.
Answered by Baroness Merron - Parliamentary Under-Secretary (Department of Health and Social Care)
The information is not available. The Human Fertilisation and Embryology Authority (HFEA) has advised that it cannot provide the information as requested due to how the data is stored on the HFEA Register.
Work is currently ongoing so that this information can be provided over the next 12 to 18 months.
Asked by: Lord Winston (Labour - Life peer)
Question to the Department of Health and Social Care:
To ask His Majesty's Government how many human eggs (oocytes) were harvested and frozen by vitrification between the years 2014–24 for social purposes according to records kept by the Human Fertilisation and Embryology Authority; and how many of these eggs were subsequently thawed in order to undertake clinical treatment using in vitro fertilisation.
Answered by Baroness Merron - Parliamentary Under-Secretary (Department of Health and Social Care)
The Human Fertilisation and Embryology Authority does not hold information on the method of freezing for the whole period requested, or the reasons eggs were frozen.
Data is available from 2014 to 2023 showing 263,692 eggs collected for patients’ own use in egg storage and 33,861 eggs thawed for patients’ own use.
Asked by: Lord Winston (Labour - Life peer)
Question to the Department of Health and Social Care:
To ask His Majesty's Government what provisions they have put in place to ensure medical follow up of children who were conceived by in vitro fertilisation following oocyte freezing.
Answered by Baroness Merron - Parliamentary Under-Secretary (Department of Health and Social Care)
The Human Fertilisation and Embryology Authority (HFEA), as the United Kingdom wide regulator of fertility treatment, has no statutory role in the medical follow up for children conceived through in vitro fertilisation, including instances where thawed eggs are used in treatment.
The HFEA’s expert Scientific and Clinical Advances Advisory Committee monitors new studies relating to assisted reproductive technologies, including any impact on children born from treatments.
Asked by: Lord Winston (Labour - Life peer)
Question to the Department of Health and Social Care:
To ask His Majesty's Government according to the records of the Human Fertilisation and Embryology Authority (HFEA), how many women undergoing egg collection for the purposes of egg storage required admission to hospital or experienced other significant morbidity following ovarian stimulation and egg collection; and how many women were reported to have experienced internal abdominal haemorrhage or other damage in the abdomen following attempts at oocyte harvest.
Answered by Baroness Merron - Parliamentary Under-Secretary (Department of Health and Social Care)
The Human Fertilisation and Embryology Authority does not categorise information on hospital admissions, significant morbidity, or internal abdominal haemorrhage or other damage in the abdomen by fertility treatment type.
Asked by: Lord Winston (Labour - Life peer)
Question to the Department of Health and Social Care:
To ask His Majesty's Government how many women have had their eggs (oocytes) frozen in each year between 2014 and 2019.
Answered by Lord Markham - Shadow Minister (Science, Innovation and Technology)
The following table shows the number of patients storing their own eggs in each year from 2014 to 2019.
Year of treatment | Number of patients |
2014 | 611 |
2015 | 906 |
2016 | 1,064 |
2017 | 1,209 |
2018 | 1,595 |
2019 | 1,937 |
Source: The Human Fertilisation and Embryology Authority (HFEA)
Note:
The data is as shown on the HFEA’s register database on 21 October 2022. This is a live database so these figures reflect the data on this day are likely to change over time. Data shown includes patients storing their eggs for future use.