IVF: What are the main reasons for failure?

The development of assisted reproductive technologies (ART) over the years has led to IVF being safer and more successful than ever. In the latest statistics published by the HFEA we have seen the following numbers: 

  • Women under 35: 31% success rate 
  • Women aged 35-37: 25% success rate 
  • Women aged 38-39: 19% success rate 
  • Women aged 40-42: 11% success rate 

However, it should be noted that these are average success rates and there is actually a wide variation in success rates from clinic to clinic.

But overall, success rates have gone up over the years; the rates above are approximately 3 times higher than they were 30 years ago. 

upset young woman looking a pregnancy test

What are the factors that can affect success in IVF? 

Sperm quality for IVF

A common misconception is that infertility is usually down to the female. The actual split is roughly even: 40% Male, 40% Female and 20% a combination of both. The male factor – essentially the quality of the sperm – is just as important as egg quality. Often, poor quality sperm can result in no fertilisation or a poor-quality embryo, which will either not implant or fail to develop and then be lost. 

We have an article which outlines the best ways to boost male fertility if you or your partner have low quality sperm.  If you are looking to improve your sperm quality, Impryl has been clinically proven to help. 

Age can affect IVF success rates

Fertility specialist, medical director Gillian Lockwood says “Human beings are actually not very fertile: even young couples have only a 1 in 4 chance of getting pregnant each month they try. And by the woman’s mid-thirties this chance has dropped to 1 in 8.“

The statistics show that as women get older, their chances of success declines. This is due to the quantity and quality of eggs decreasing with age. IVF works by taking medication which stimulates a response from your ovaries and the clinic selects the best eggs for fertilisation. Due to the number and quality of eggs declining this makes the process more challenging and increases the likelihood of failure. 

IVF medication can cause OHSS (Ovarian Hyperstimulation Syndrome) 

When you go through IVF you have to take medication which stimulates egg production. As mentioned previously if you don’t respond to this medication IVF can fail. On the other hand, if you are sensitive and respond strongly to the medication you can also have a problem of over-response and this is where ovarian hyper-stimulation syndrome (OHSS) can occur. This syndrome can be very serious.

OHSS is common in those with PCOS (Polycystic Ovary syndrome), however, clinics now regularly scan and carefully adjust the dose to minimise risk. They will also tend to freeze any resulting embryos to help allow your hormone levels to return to normal and try embryo transfer on a subsequent cycle to ensure safety.

The use of antagonist protocols also reduces the risk and incidence of OHSS.

This is becoming less of an issue as research around the topic has helped clinics to identify key indicators and understand those who are at most at risk. Only 3-8% of those going through IVF suffer a moderate form. Fewer than 2% require admission to hospital (source). OHSS complications can sometimes result in the cancellation of an IVF cycle and therefore the failure of the procedure. 

Obesity can affect IVF success

1 in 4 adults in the UK suffer from obesity and that number is rising. To give yourself the best chance at success in IVF you will be recommended to get your BMI down to a healthy weight.  Research has shown that ‘Overweight women have a higher incidence of menstrual dysfunction and anovulation. Overweight and obese women are at a high risk for reproductive health. The risk of subfecundity and infertility, conception rates, miscarriage rates, and pregnancy complications are increased in these women.’

There is also evidence indicating that obese men have poorer quality sperm.

Smoking during IVF treatment affects success rates

A comprehensive study has shown that smoking can affect the outcome of IVF/ICSI treatments negatively. It can lead to reduced fertilization rates, pregnancy rates (PR) and live birth rates as well as to significantly higher chances of miscarriages or ectopic pregnancies. If you are going to go through IVF then quitting smoking is a must!  That applies to both men and women.

Other reasons IVF can fail:

There is no guarantee of success 

Despite advancing technologies and an increased understanding of the process it is still likely that IVF cycles fail. All you can do is give yourself the best chance. We advise that you lead a balanced lifestyle and supplement yourself with Impryl as soon as you begin trying to conceive in order to give yourself the best possible chance. 

Good luck in your journey! 


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