King’s Speech

Lord Winston Excerpts

Wednesday 20th May 2026 Lords Chamber

[Lord Winston (Lab)]

It is with great pleasure that I follow the noble Baroness, Lady Walmsley. I want to offer something of importance to all women. A newborn girl has around 1 million eggs at birth in her ovaries. By puberty, most of those microscopic eggs have already disappeared, often leaving some 300,000, according to our laboratory calculations. This loss continues in all women throughout childbearing life. By the age of 45, few viable eggs are left in the ovaries and the chance of women getting pregnant spontaneously is less than 2% per month.

No medical treatment prevents this loss of eggs, so egg freezing is increasingly used to preserve female fertility. Frozen eggs are stored in liquid nitrogen but, unlike freezing embryos, which is highly successful, egg freezing is much more difficult—for technical and scientific reasons that I do not have time to explain. Egg freezing is a massive industry, mostly in private clinics. Many women are being encouraged to freeze their eggs. To have much chance of success, eggs must be collected and frozen early in reproductive life, before a woman is 30 or, at the latest, 35.

Information is available for the last 15 years or so from the Human Fertilisation and Embryology Authority, which reports all this data to Parliament in some form. IVF is needed for frozen eggs to become babies, so this is relevant to the HFEA’s work. About eight years ago, the authority claimed that the chance of a woman getting pregnant with her frozen eggs was around 13%. Sadly, this estimate was grossly inaccurate, because its report counted only the transfer of embryos derived from frozen eggs to the uterus. There are many steps in egg freezing before embryos are created. Freezing itself has a failure rate, as we will see in a second, as do many early stages which are not being recorded. To get enough eggs from the ovary, they must be reasonably mature eggs. They must be produced through fertility drugs given in increasing doses, not without some risks.

However, some eggs do not freeze well and do not mature properly. At least 20% that are frozen do not thaw normally. Already there is an increased risk of damage from the thawing. When they have gone through this process, they are then exposed to sperm if they are normal, but they may not fertilise. Of those that are fertilised, many do not develop into embryos. Others may have chromosomal abnormalities—aneuploidy—and other cellular abnormalities which prevent their chance of being a normal embryo.

The HFEA’s figures from the last 10 years record about a quarter of a million eggs being currently in store—263,692 eggs have been frozen and stored. Some 34,000 eggs have been used for the treatment of women in the last 10 years. From these, 2,949 embryos were formed and transferred. That resulted in 609 women getting pregnant, about a 20% success rate. However, there were at least 93 miscarriages, which is 15% of the pregnancies. Therefore, after thawing 34,000 eggs, the real success rate of egg freezing is a pregnancy rate of around 1.7%.

This is not being told to the women. It is not fully reported in the numbers of live births. We do not know the precise status of these embryos. We do not have follow-up; we do not have information about any serious side-effects of the treatment. The HFEA says that it no longer keeps such statistics and that it could take up to 18 months for the Minister to get information.

Egg freezing means a great profit for private clinics. Patients usually pay £5,000 for each treatment but sometimes more—sometimes over £10,000. Some clinics have boasted to me—I have this on record—that they get a better than 60% pregnancy rate after egg freezing, which is more than what is achieved by sex in a comfortable bed. I hope that my noble friend the Minister will write to me about these deeply distressing statistics. They are largely hidden from women, who are frequently told by clinics that they should take out an effective insurance plan for their future well-being and happiness. This is not good information.