Fertility preservation is the process of freezing eggs (oocytes), sperm, embryos or reproductive tissue so that a person can use them to hopefully have their own biological children in the future.  Preservation of fertility is possible for men and women, girls and teenage boys.

Whether a treatment is available on the NHS depends on where you live.  Generally people who need treatment for medical reasons, for example for cancer, can have this on the NHS, whereas those who are having it as a lifestyle choice can’t.

There are many reasons why fertility preservation might be considered, for example:


  • If you (or your child) are about to have treatment for a serious condition (such as cancer) that could affect your (or your child’s) ability to have children in the future
    • Certain types of cancer treatment including chemotherapy and radiotherapy can cause infertility
  • If you’re in the Armed Forces
    • You may choose to freeze your sperm, eggs or embryos before deployment to preserve your fertility in case of injury
  • If you’re not ready for a family yet
    • You might want to preserve your fertility because you haven’t met the right partner yet, you don’t feel financially or emotionally ready or you have other life plans you want to pursue
  • If you’re a transgender person
    • If you’re a male transitioning to a female or a female transitioning to a male, you may want to preserve your fertility before you start hormone therapy or have reconstructive surgery

There are several different ways of preserving fertility:

Egg Freezing

Egg freezing involves collecting a woman’s eggs, freezing them and then thawing them at a later date so they can be used in fertility treatment.  Women essentially undergo the first half of an in vitro fertilisation (IVF) cycle which involves taking drugs to stimulate the ovaries and then undergoing a procedure under sedation (or occasionally general anaesthetic) to collect the eggs.  At this point, instead of fertilising the eggs with sperm, the eggs are frozen and stored in tanks of liquid nitrogen.  When you want to use the eggs, they are thawed and those that survive intact will be injected with sperm.  An embryo is then transferred into your womb.  It may be recommended for you to take hormones for a few weeks prior to embryo transfer to nourish the lining of the womb beforehand.

Egg freezing takes on average between 2 and 3 weeks so if you are waiting to start treatment for cancer, this delay, and the effect it may have on your prognosis, should be discussed with your oncologist.  Some women are not well enough to freeze their eggs at the time of their cancer diagnosis.

In order to have a live birth following egg freezing, it is preferable to freeze at least 15 eggs.  Depending on your ovarian reserve, it may be recommended to have more than one cycle of stimulation to maximise the number of eggs that can be collected and stored and therefore increase the chances of you having a baby in the future.  Some women may have insufficient ovarian reserve to warrant freezing their eggs.

Ovarian Tissue Freezing

Ovarian tissue freezing is a fertility preservation option for women who are unable to freeze their eggs and for younger girls who haven’t started ovulating.  It is only available in specialist centres.  It involves an operation under a general anaesthetic to remove part or all of an ovary.  This is usually possible using keyhole (laparoscopic) surgery.  The tissue is frozen and when a pregnancy is desired, transplanted back into the body (usually back into the pelvis).  This requires another operation, again usually keyhole, under general anaesthetic.  Some women may then be able to get pregnant naturally whilst others may require IVF.  The ovarian tissue may be removed when your family is complete.

Sperm Freezing

Sperm freezing is the most effective method of preserving man’s fertility and can be stored from as young as 13 if needed.

You may want to consider sperm freezing if:

  • You have a condition, or are facing medical treatment for a condition that might affect your fertility
  • You are about to have a vasectomy and want sperm available in case you change your mind about having more children in the future
  • You have a low sperm count or the quality of your sperm is deteriorating
  • You have difficulty producing a sperm sample on the day of fertility treatment/you may not be around at the time of treatment e.g. if you work away a lot
  • You are at risk of injury or death
  • You are a male transitioning to a female you may want to preserve your fertility before you start hormone therapy or have reconstructive surgery, both of which can lead to the partial or total loss of your fertility


IVF using frozen sperm is just as successful as IVF using fresh sperm and there are no known risks from using frozen sperm in treatment.  Not all sperm survive the freezing and thawing process though.  Before sperm is stored, it is usually divided between a number of ‘straws’, which means that not all sperm needs to be thawed at once and it can be used in multiple treatments.  The standard storage period for sperm is 10 years but some men in certain circumstances can store their sperm for up to 55 years.

When you want to use your sperm, you and your partner will need to have fertility treatment which may involve either insemination, IVF or intracytoplasmic sperm injection (ICSI).  Your doctor will discuss this with you when the time comes.

Testicular Tissue Freezing

Testicular tissue freezing is a specialist technique to preserve the fertility of men who do not produce viable sperm in their ejaculate.  It involves an operation under general anaesthetic.  When a pregnancy is desired, sperm obtained from testicular tissue is injected into eggs (ICSI), so the woman needs to undergo ovarian stimulation and egg collection.  The injected eggs are then incubated and an embryo transferred into the uterus, between 2 and 6 days later.

Embryo Freezing

 Women undergoing treatment for conditions that may affect their fertility, for example cancer, can freeze their eggs (see above) but, if they are in a relationship at the time, they could freeze embryos instead.  Embryos are more likely to survive the freeze thaw process than eggs.  Although most embryos survive the freeze thaw process, not all do.  Once thawed, success rates are comparable to fresh embryos.

The process for freezing embryos is similar to freezing eggs.  Women essentially undergo the first half of an IVF cycle which involves taking drugs to stimulate the ovaries and then undergoing an operation under sedation (or occasionally general anaesthetic) to collect the eggs.  The eggs are then fertilised with sperm using standard IVF or ICSI depending on the quality of the sperm.  Once fertilised, the embryos are frozen in tanks of liquid nitrogen until you’re ready to use them.

Not all embryos are suitable for freezing so only good quality embryos will be chosen to freeze.  The standard storage period for embryos is usually 10 years although, in certain circumstances, this can be extended for up to 55 years.  Embryos are not affected by the length of time they are frozen for.

Before embryos are frozen, it is important that you and your partner give consent by signing the necessary forms.  These detail exactly what you would like to happen to your embryos in a variety of different circumstances for example if you or your partner die.  If one person withdraws consent at any point before the embryos are transferred, then the embryos cannot be used in treatment and they will be allowed to perish.

More information on fertility preservation is available from the Human Fertilisation and Embryo Authority, HFEA