Arrow In this section

Why is age important?

Age is an important independent factor affecting female fertility. Women are waiting longer to begin a family. Age related decline in fertility may take place at a quicker pace than what most women expect. This is due to age related decline in the number and quality of eggs in the ovaries. Decline in natural fertility accelerates after the age of 35 years and this decline is not completely offset by assisted conception treatments. The chance of a live birth following IVF treatment with fresh embryo transfer varies with age. This is 37% for women below 35 years of age and declines to 15% for a woman who is 40 years of age (National averages, HFEA Trends and Figures, published March 2018).

Age and egg quality

Advancing age also has an impact on egg quality. An important reason for decline in egg quality is due to increased frequency of genetic abnormalities in the egg with increasing age. This results in lower success with assisted conception and an increase in miscarriage.

Women who are over 35 years of age should seek advice sooner from their GP if they are finding it difficult to achieve a pregnancy.

What is ovarian reserve?

Women are born with a fixed number of follicles in their ovaries. At birth this may number around 1 million. By the onset of puberty this number would have dropped to around 300,000. Only about 300 are ovulated during the reproductive years and the rest of the follicles are lost by a process called atresia. This process of atresia is gradual and occurs even during pregnancy or when a woman is on the contraceptive pill. The rate of loss of egg-containing follicles may vary from woman to woman. Smoking accelerates this loss of follicles. This decline in egg quantity is called ‘loss of ovarian reserve’. Blood tests for hormones such as follicle stimulating hormone (FSH), Anti-mullerian hormone (AMH) and an ultrasound for checking the antral follicle count (AFC) give an assessment of ovarian reserve.


What about women with other medical conditions?

Thanks to advances in medical care, we can offer assisted conception treatment to women with underlying medical conditions, such as Diabetes, heart disease, blood disorders, kidney disease etc. Women with underlying conditions are often referred for such treatment directly by their medical consultant team or by their GP.

Every woman with a pre-existing medical condition is assessed individually to ascertain the risks to her with assisted conception treatment and pregnancy. Often there is a delay in starting treatment as an assessment is requested from their medical consultant regarding suitability to proceed with assisted conception treatment and risks with pregnancy. An opinion is sought from the pre-conception clinic at Saint Mary’s Hospital to assess risks in pregnancy to the mother and baby. Changes to medications may be requested prior to starting assisted conception treatment.

In situations where the woman has a life threatening medical condition, the decision to proceed with any treatment will be taken jointly in a multi-disciplinary meeting. Rarely, assisted conception treatment may be refused based on input from different specialties and a full discussion in our team. If attending the clinic for your first appointment, you should bring a list of all medications and medical correspondence.


Lifestyle factors:


Research has shown IVF is more successful when women are within the ideal weight range for their height. There are also added risks to a pregnancy when women are overweight. Most CCG’s only fund NHS IVF for women with a Body Mass Index (BMI) between 19-30. A healthy balanced diet for both partners can help increase success. 

Folic Acid and Vitamin D

Women are also advised to take Folic Acid supplements daily (0.4mg) when trying to conceive. We also advise all women trying to have a baby to take 10 micrograms of Vitamin D daily. You can obtain Folic Acid and Vitamin D from any chemist.


Both partners MUST NOT smoke when undergoing NHS-funded IVF treatment as, aside from the known damage to health this causes, smoking decreases success rates of IVF.  If either of you smoke, you will be referred back to your GP and can only be re-referred once you have been smoke-free for 3 months.


NICE guidelines advise not drinking to excess and drinking no more than 1 or 2 units of alcohol once or twice a week. A unit of alcohol is about the same as a small glass (125 ml) of wine or a half-pint of beer or lager. If you are a man, your fertility is likely to be affected if you drink more than 3 or 4 units of alcohol a day. Drinking excessive amounts of alcohol can affect the quality of a man’s sperm.


It is also important for women to have an up-to-date smear test before starting a treatment cycle as you will not be able to have this done routinely once pregnant.


Other factors:

Please be aware that we are obliged to have a closure period once every year to ensure essential safety checks and maintenance of theatres and laboratories can be carried out.

This may include equipment checks, servicing and environmental checks such as air quality and cleaning.

This closure period takes place in December but this will affect some treatment requests from November as the need for theatre or laboratory services may fall within the closure period.

If you have any queries regarding the impact this may have on your individual treatment cycle please contact the IVF Nurses on (0161) 276 6000.