Zita West Clinic IVF technology

Technologies to help improve IVF success

At the Zita West Clinic we pride ourselves on using evidence-based science and technology to improve IVF success rates. Here are just a few of the technologies we can use to help you have a baby.

Endometrial Receptivity Analysis

Endometrial receptivity analysis (ERA) is a way of finding out when the lining of the womb is most receptive, meaning we can then decide a time for embryo transfer that’s most likely to result in success. While there can be many reasons that an embryo won’t implant, sometimes there may be a problem with the endometrium which can then cause failed cycles.

What is the ERA procedure?

ERA testing can be doing either during a natural cycle or a conventional IVF cycle, with a test similar to a smear where tissue it taken from the womb lining. This is then analysed to see when the endometrium would be most effective to help decide the timing of implantation.


Time lapse technology

Time lapse embryo imaging is an additional procedure available to all our patients to help make embryo selection even more effective.

Once the eggs have been fertilised, photographs are taken of the embryos, without disturbing them, every few minutes. Calculations about what the embryo should be doing at specific points in time are then used to analyse the health of the embryo to see their chances of success.



As we know, one set of chromosomes from the sperm and one set of the egg form the first cell of an embryo, but if the cell doesn’t have the right amount of chromosomes (known as aneuploidy), this can lead to implantation failure, miscarriage or a baby born with a serious condition.

At the Zita West Clinic, we can carry out a genetic screening test called Pre-implantation Genetic Testing for aneuploidy (PGT-A) on embryos produced during an IVF treatment cycle. PGT-A helps us select the best embryo for transfer and may improve your chance of achieving a successful pregnancy.

There are many benefits to this technology, from potentially reducing the number of IVF cycles needed, to giving more confidence in transferring a single embryo.

You can find out more key information about PGT-A genetic testing, including its potential risks and evidence of success, on our Genetic Testing page.

Who should consider PGT-A?

For those who have experienced miscarriages or failed treatments then we may suggest this for you. There has also been research to suggest that over half of human eggs have chromosomal issues which increases with age, so many women who are over 35 may also choose PGT-A.

The PGT-A process

When embryos reach the Blastocyst stage after 5-6 days, they contain around 100 to 200 cells arranged into an inner cell mass and an outer ring of cells. The inner cell mass is made up of stem cells that will go on to form the foetus, while the outer ring (the trophectoderm) will become the placenta. A few of these trophectoderm cells are carefully removed by our embryologists for assessment before freezing the embryos.


For more information on any of these treatments, or to book with one of our doctors to discuss your next cycle , call us on 0808 196 4060 or email enquiries@zitawest.com

HFEA comment

Is Endometrial Receptivity Analysis effective?

The independent regulator of fertility treatment, the Human Fertilisation and Embryology Authority (HFEA), has developed a ‘red-amber-green’ rating system for treatments that are optional extras in fertility treatment. They consider that the only way to be confident that a treatment is effective enough to be used routinely is to carry out a randomised controlled trial (RCT). In an RCT, patients are assigned randomly to two groups: a treatment group, given the new treatment and a control group, given either a well-tried treatment or a placebo.

The HFEA has given reproductive immunology tests and treatments, such as Endometrial Receptivity Analysis, a red rating because it considers that there is no evidence these tests or treatment increase the overall chances of having a baby. We recommend that you read the information on the HFEA website before making a decision about having the tests and treatment outlined here.

We believe it is important that you know and understand that these treatments remain unproven. We can provide you with detailed information documents about these treatments, which we would recommend you read carefully before you decide to have these treatments.

Are there any risks to ERA testing?

If you are considering using any of the tests or treatments listed, your doctor will make sure the medication or treatment is safe for you and explain the possible risks and side effects. We also have separate information leaflets about each treatment that includes this information.

Is time lapse embryo imaging and CAREmaps effective?

The HFEA has given time-lapse imaging an amber rating because although there have been studies looking at whether time-lapse imaging can improve birth rates, they don’t consider that there is enough evidence from RCTs to prove that time-lapse imaging improves your chance of having a baby.

It is important to consider though that CAREmaps combines time-lapse imaging with the use of a unique embryo ranking model developed by the CARE Fertility group.. CARE’s own data from a study published in 2017 of more than 23,000 treatment cycles showed a highly significant increase in births when CAREmaps was used to select embryos for patients aged younger than 38 using their own eggs. A paper published by CARE in 2019 showed that CAREmaps is superior for selecting embryos most likely to result in a birth than standard selection methods.

What are the side effects and risks of time lapse technology?

There are no risks that have been identified from the use of time lapse monitoring of embryos. It is possible, however, that our embryo analysis computer algorithm, CAREmaps, might identify that none of your embryos are suitable for transfer and if that happens your doctor will work with you to identify the best way forward, taking account of all of the information from your treatment cycle, the embryo monitoring and your medical history.