IVF - Surrogacy Blog


What is the Endometrial Receptivity Array (ERA) test?

IVF is expensive and the failure of an IVF cycle can be very disturbing. If you have had a failed IVF cycle despite good quality embryos and a good transfer process at the hands of an experienced doctor, you may consider the endometrial receptivity array, commonly known as the ERA test.

The reasons for IVF failure are not always obvious and ERA test can optimise the chances for successful implantation, especially if there is a concern about your endometrial lining, which is not evident in any of the other tests.


What is the ERA test?

The endometrial receptivity array (ERA) test allows the doctor to determine whether or not your endometrium (womb lining) is in the optimum condition for allowing an implanted embryo to attach.

Good condition of the endometrium is essential for successful embryo implantation. This includes the endometrium being at a specific thickness and the local blood flow increasing.

During your menstrual cycle, there is a short period of time during which your endometrium is in this optimal condition, this is referred to as your ‘implantation window’. The ‘implantation window’ is thought to be around 6-10 days after ovulation.

The ERA test can determine whether this ‘implantation window’ is happening for you at the expected time. Therefore, this can allow your doctors to better time your embryo transfer.

(A different technique called the endometrial scratch is used by some doctors to improve local blood flow and aid in embryo implantation.)


How does the ERA test work?

The ERA test is a genetic method which evaluates gene expression within your endometrial cells. There are over 200 genes that work to determine endometrial receptivity, and these genes are all analysed using this test.

The gene expression levels are interpreted and used to classify the endometrial sample as either ‘receptive’ or ‘non-receptive’. This analysis is referred to as Next Generation Sequencing (NGS).


How is the ERA test performed?

For the ERA test, your doctor will take a small sample of your endometrial tissue during a specific point of your cycle.

This is known as an endometrial biopsy, which is a very quick and easy procedure, as described below:

  1. A thin catheter will be inserted through the cervix and into the womb.
  2. Suction is then created in the catheter using a plunger, allowing a small sample of endometrial tissue to be withdrawn.
  3. This tissue is then sent for analysis and results are usually provided about three weeks later.

The biopsy may cause some slight discomfort whilst being performed, but it is usually short lived. You may also get some slight cramping and spotting after the procedure.


Will I need an ERA test?

This test can be particularly useful in cases of recurrent embryo implantation failure, where there is no problem with embryo quality or any other obvious cause.

A pilot study looking at the effect of ERA testing for patients with previous implantation failure shows that successful implantation can be achieved when the results are used to time embryo transfer effectively.

There appears to be little benefit to patients without previous implantation failure having an ERA test.


What are the advantages of the ERA test?

Evidence shows that 25 percent of recurrent implantation failure patients who undergo the ERA test had a non-receptive lining at the expected implantation time. Embryo transfer at this time is likely to lead to implantation failure, causing IVF failure, and consequent emotional and financial distress.

By enabling doctors to determine the specific point in your cycle, where your womb lining is optimal for implantation, your chances of IVF success are greatly increased.

This test would not need to be repeated with subsequent IVF cycles as your ‘implantation window’ is unlikely to change over a short period of time.

The ERA test is known to have high sensitivity and specificity for accurately determining endometrial receptivity.


How much does an ERA test cost?

The ERA test will form an additional part of your treatment, and will therefore likely incur an extra charge to the standard cost of your IVF treatment.

Given that the ERA test uses revolutionary, new technology, the cost of the test is relatively expensive. However, if you weigh this against the overall high cost of IVF treatment, taking into account that it may significantly increase your chances of success, it does not seem an unreasonable extra cost.

The cost of the test can vary greatly depending on your geographical location and the clinic you choose.

To give you an idea of the approximate cost of ERA test:

  • In the UK – between £1200 and £1500
  • In the USA – between $750 and $1000
  • In Europe – between €800 and €1200
  • India – between INR 3,500 and INR 7,000

Obviously, if you and your medical team feel that the ERA test is something that could improve your chances of success, then it is advisable to consider going ahead with this.

As a relatively simple and easy test, this could arm you with the information needed to better plan your embryo transfer and improve your chances of IVF success.


Do you have any comments or questions regarding ERA test with IVF treatment? Let’s hear them below:

What is endometrial scratch? How does it improve IVF and IUI success?

If you have been reading all about IVF, as most people do before starting the treatment, you must have come across the procedure called endometrial scratch, which is known to improve IVF success rates.

Your doctor may offer you an endometrial scratch if you have had several failed IVF or IUI cycles despite having high quality embryos implanted. This technique may help to improve your chances of an embryo successfully implanting in the uterus wall and resulting in a pregnancy.


What is endometrial scratch?

Endometrial scratch, also sometimes call an endometrial biopsy, is a procedure in which your doctor makes a superficial scratch in your uterus lining (endometrium) at a certain point during your menstrual cycle to better prepare your womb for the implantation of an embryo.

It is like a small injury to the uterine lining, which makes it more receptive to the embryo.

Evidence suggests that performing this procedure for women who have had failed IVF or IUI cycles with high quality embryos, can increase their chances of having a baby.

How is it performed?

The endometrial scratch is usually performed around day 21 of your cycle, i.e. in the luteal phase. This should be roughly around a week after ovulation and a week before your next period is due.

Endometrial scratching usually takes only around 15 minutes.

It is important that you do not have unprotected sex during the cycle that you receive this treatment. This is because endometrial scratching may damage an existing pregnancy.

The procedure itself is not very painful and very similar to a smear test. Anesthesia is not required but you will be prescribed some analgesic medication to subside the minor pain.

Following are the steps in endometrial scratching procedure:

  • You will need to sign a consent form prior to the procedure. This will confirm that you have not had unprotected sex during this menstrual cycle.
  • A speculum will be inserted into your vagina, to enable your doctor to see your cervix. The cervix will then be wiped with a sterile gauze.
  • A thin catheter will then be passed through the cervix and used to scratch the endometrium. This may create some mild period-like cramps.
  • The catheter will then be removed.

You may experience some bleeding after the procedure, so it is a good idea to take a sanitary towel along with you.


Do I need endometrial scratch during IVF?

An endometrial scratch could be helpful if you have had several failed IVF or IUI attempts, with no obvious cause of implantation problems.

There is no real evidence available to suggest that endometrial scratching will help you if you are undergoing your first cycle of IVF.

The procedure is not offered by all doctors, although if results continue to be promising, it could help women facing repeated IVF failure.


How will it improve my IVF and IUI success?

You may be wondering how exactly endometrial scratching will work to improve your chances of success with IVF and IUI.

Well the scratching procedure triggers a reaction from your body, involving the release of inflammatory substances and hormones, which work to heal the scratch. The release of these substances can make your womb lining more receptive to embryo implantation and therefore, increase the likelihood of a successful treatment cycle.

By intentionally injuring the womb lining, we also increase the blood flow to the area. This too creates a more conducive environment for your embryo to implant.

Research shows that endometrial scratching significantly increases the implantation rate in women who have had previous implantation failures.


What are the risks?

The procedure involved in endometrial scratching is very safe. It is a relatively straight forward procedure, which doesn’t have many reported risks.

You may experience some period-like pain after the procedure, along with some light bleeding.

There is a small risk of pelvic infection following the procedure, as infections of the cervix may be spread into the uterus. You will need to contact your doctor straight away if you experience any of the following symptoms, in the days following your procedure:

  • Unexplained fever
  • A feeling of being generally unwell
  • Bleeding which does not settle down
  • A foul-smelling discharge from the vagina
  • Persistent pain in the lower abdomen

There is also a very small risk (just around 1%) of miscarriage should you become pregnant following the procedure.


How much does it cost?

As with any additional procedures there is a charge for carrying out an endometrial scratch. The cost of endometrial scratch is just about $200 – $300 but it is not offered commonly yet. More research is needed to know if endometrial scratch can indeed improve IVF results.

(Related read: How PGS improves IVF results)

Endometrial scratching is a rather simple procedure, which according to initial reports, may significantly increase your chances of a successful pregnancy. Given the high cost of IVF treatment, you may discuss endometrial scratching with your doctor and see if such a procedure can raise your chances of IVF success.

The additional cost and minimal risks of this procedure should be outweighed by the benefits.


Do you have any experience or questions regarding endometrial scratching? Please share them below:

How many embryos to transfer in your IVF cycle?

Have you thought about how many embryos to transfer in your IVF cycle, or just left the decision to the doctor?

Different countries have different policies regarding the number of embryos that should be transferred in an IVF cycle, and in countries where multiple embryo transfer is allowed, this decision is best made after a thorough discussion with your doctor.

It is important to remember that the primary goal of IVF treatment is to deliver a single, healthy baby at full-term.


How will I decide how many embryos to transfer?

Transferring multiple embryos raises your chances of a successful pregnancy. However, there are also risks associated with multiple embryo transfer.

There are certain factors that you will need to take into consideration when making this decision, these include:

  • The quality of your eggs
  • The quality of your embryos
  • Your age
  • Previous failures with fertility treatment
  • Any medical conditions, such as, uterine malformations, that may make successful implantation less likely


Put back one or two embryos?

Weighing up the risks and benefits, most doctors will now decide to transfer back only a single, good quality embryo. This is to limit the chances of a multiple pregnancy, which can pose health risks to you and your babies.

When transferring only one embryo, your chances of a multiple pregnancy are only about 1-2%. However, this can be as high as 35% if you transfer back 2 embryos.

Our associate IVF doctors in Malaysia presented the research below, which shows that a day-5 transfer of one high quality blastocyst provides very high clinical pregnancy rate of 82.9 percent and implantation rate of 79.5 percent.

Further research supports this, showing that a transfer with a single, good quality embryo is just as effective as a double transfer in women under the age of 38 in their first IVF cycle.

However, this data looks specifically at younger women, with the majority included in the studies being under 40 years old. Maternal age can affect the success rates of IVF cycles and, will therefore be something you will want to take into consideration when deciding whether to transfer one or two embryos.

Your doctor may decide to transfer two embryos if you:

  • are over 40 years
  • have low quality embryos
  • have had previous failed fertility treatments
  • have a medical condition which may affect successful implantation

Research has shown that in women over the age of 40, risks of multiple births and other complications associated with transferring two embryos are lower than for younger women.

Our top fertility doctors in Malaysia also presented the below report after studying 396 IVF cases

Most clinics will offer you embryo monitoring, to ensure only the highest quality embryos are transferred. This can often negate the need for transferring multiple embryos.


Are three embryos ever transferred?

Most regulations restrict doctors to transferring a maximum of three embryos at one time. However, a lot of clinics will choose to transfer just one or two embryos, depending on your circumstances.

Research has shown that the risks of transferring three embryos outweigh the benefits. This study published in The Lancet shows that the transfer of three or more embryos should be avoided as it can significantly increase risks such as premature birth, and it does not appear to increase the chances of a live birth either.


Transferring more embryos on day-3 vs. day-5

The majority of fertility clinics will choose to transfer either one or two good quality embryos on day 5. At this stage, your embryos will be blastocysts and transferring in this way, usually results in a higher pregnancy rate and a lower risk of multiple pregnancies.

However, you may be advised to transfer your embryos at day 3, particularly if you have a low number of poor quality embryos. This is because the uterine environment may provide a better chance of growth for the embryos as compared to the IVF laboratory.

Sometimes, if you do have embryos transferred on day 3, your doctors may advise you to transfer up to four embryos to improve your chances of a successful pregnancy.

However, if your clinic insists on transferring embryos on day-3, they may not be well equipped. You must consider this factor while selecting your IVF clinic.


Risks of multiple embryo transfer

The risks associated with multiple embryo transfer stem from an increased risk of multiple pregnancies.

Multiple pregnancies can carry risks for both you and your babies, these include:

For your babies:

  • premature birth
  • low birth weight
  • birth defects
  • chronic medical problems

For you, the mother:

  • anaemia
  • pre-eclampsia
  • gestational diabetes
  • need for a C-section
  • Excess blood loss during delivery


Embryo transfer policy in different countries

Given the risks to both mother and baby, laws have been put into place to limit the number of embryos that can be transferred at one time.

These laws and regulations differ considerably between different countries:

  • In Spain – a maximum of three embryos are allowed to be transferred
  • In Bulgaria and Greece – it is dependent on maternal age and the number of previous failed IVF attempts
  • In Cyprus – a maximum of three embryos are allowed
  • In the UK – a maximum of transferred embryos can be transferred; three if the woman is over the age of 40
  • In the USA – there are no specific laws in place, just guidelines recommending:
    • no more than two embryos for women under 35
    • no more than three embryos for women 35-40
    • no more than five for women over 40
  • In India – there are no specific laws in place
  • In Thailand – there are no laws regarding this
  • In Malaysia – there is no law, although are associate doctor has demonstrated over time that a very high pregnancy rate can be achieved with a single, good quality blastocyst


Cost of embryo transfer

Given the high cost of IVF treatment, you will want to maximise your chances of a successful pregnancy as much as possible.

The cost of embryo transfer can vary significantly between different countries. The following are average costs of embryo transfer:

  • In USA: $3000
  • In UK: £1000
  • In India: $500
  • In Thailand: $550
  • In Malaysia: $1,000

Patients will often travel to countries, such as India for IVF because of the lower cost of treatment and the less stringent regulations regarding the number of embryos that can be transferred.

Transferring multiple embryos may save you the costs of further IVF treatment. Alternatively, you may freeze any remaining embryos; giving you the option to pay for a frozen embryo transfer should you need further treatments. This will work out significantly cheaper than a further full IVF cycle.

Whether you opt for IVF in Malaysia, Thailand, India, Spain, or Mexico, all good clinics will provide the option to freeze your embryos, which can be transferred later, eliminating the need for a full IVF cycle again.

Given all of the factors that need to be considered, the decision on how many embryos to transfer during your IVF cycle is a very important and difficult one. This should be carefully discussed between yourself, you partner, and your medical team, and the decision should be based on achieving the best result, keeping in mind your unique circumstances.


For more information on IVF and the number of embryos to be transferred, please get in touch using the form on this page.