23/10/2014 08:54 BST | Updated 22/12/2014 05:59 GMT

Egg Freezing -12 Frequently Asked Questions

Egg freezing is in the news this week as Apple and Facebook have announced that they will offer egg freezing to their female employees. There is a lot misinformation about egg freezing and so here are 12 frequently asked questions and their answers.

1.Why do women freeze their eggs?

Previously, it was mainly used for women diagnosed with cancer to preserve their fertility before cancer treatment. Nowadays, it is used by women who want to postpone having children. It could be for a number of reasons - not having an ideal partner, pursuing education or career, caring for parents or just to take pressure off relationships.

2. Do all women of similar age have the same number of eggs in their ovaries?

Not always. If you have a family history of early menopause, you are at risk of having an early menopause and thus fewer eggs for your age. Please ask your mother for her age at menopause. If you have taken steroids or have had ovarian surgery, you may have fewer eggs for your age. Endometriosis of ovaries can also affect egg quantity and quality.

3.How can I find out how many eggs are there in my ovaries?

You need to see a fertility expert and have a detailed ultrasound scan and blood test for Anti Mullerian Hormone (AMH). An antral follicle count (AFC) with Doppler blood flow scan can give more information.

4.What does the egg freezing process involve?

The egg freezing cycle involves taking daily injections of follicle stimulating hormone (FSH) from second day of your period for around 10 days with a small needle under your skin. You will have 3-4 ultrasound scans and blood tests to monitor the growth of your follicles. Once your follicles have ripened as shown by scan and oestrogen levels in your blood, you will receive a trigger injection under the skin to mature the eggs. The egg collection is planned 36 hours afterwards.

5.How are eggs collected?

You are given mild sedation so that you will not feel any pain. Eggs are collected by a doctor emptying the fluid from follicles by passing a needle through the vagina into the ovary. The procedure lasts for around 15-25 minutes. You will be told about how many eggs are collected after the procedure. You will need to rest at home after your egg collection.

6.How can I make sure that I reduce my risks and increase chances of having good eggs?

It is important that you do not smoke, eat healthily and are not under-weight or over-weight. Modern stimulation protocol within your own cycle with the use of GN RH analogue for trigger can help to obtain good quality eggs and also eliminate health risks such as ovarian hyperstimulation syndrome. Checking blood flow to your follicles during monitoring can help to identify good eggs. Aiming for "quality" is paramount.

7.How many eggs should I freeze?

It depends on your age and egg reserve. If you are under 36, we aim to freeze around 12 eggs. If you are older, we are likely to get fewer eggs for freezing. It is important that very high doses of stimulation are not given just to get very high number of eggs. It can compromise the quality of eggs and put your health at risk.

8.What is the best method for freezing?

The best method for freezing eggs is rapid freezing also known as vitrification. It avoids formation of ice crystals. The survival rates for eggs with this method can be more than 80%. If you freeze 12 eggs, 8 or 9 eggs are expected to survive

9.What is the best time to freeze eggs?

The earlier is better for egg freezing. The ideal age would be from mid twenties to early thirties.

10.What is the success rate?

The success rate depends on the age of the woman and method of egg freezing. With younger women and the use of vitrification provide highest success rates. Recent research confirms the need to freeze around 12 eggs for women under 36 to have up to 50% chance of having a child later, compared to 7% for an older group of women with fewer eggs. The success rate reduces with age of eggs.

It is not a cast iron insurance policy but it is offers some women a chance of conceiving with their own eggs if they do not leave it too late.

11.How many babies have been born following egg freezing?

There are nearly 2000 healthy babies born following egg freezing.

12.How much does it cost?

The total cost of one cycle of egg freezing could be around £3500- £4500. Always question if high doses of drugs are prescribed, as they cost more and may not be necessary. There is an annual storage fee of around £200 and the current standard storage time is 10 years in the UK.