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:
- 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.