Single Embryo Transfer: What is the Impact of an Embryo Split?


Over the years, stories about parents having more than one baby because of IVF have struck fear in the hearts of those in search of help from IVF practitioners. Although embryo splits can occur, many stories you read online are either outdated, without context, or fabricated to intimidate intended parents from pursuing IVF. 

Many aspects regarding IVF have changed in recent years, however, there is always that question of ‘what if?’. That’s why we want to set the right expectations around one of the more common fears surrounding IVF and how it relates to a surrogate: The risks of an embryo splitting in utero.

What is a Single Embryo Transfer?

To set the stage, it’s important to know how technology and IVF methods have changed over the years. In the past, IVF experts used to rely on Multiple Embryo Transfers to increase success rates. The idea was to implant several embryos, with the notion that the strongest would be likely to succeed, while the others would probably not. Naturally, there were cases, although rare even then, where multiple embryos would take hold in the uterus.

However, today’s approach is much safer. Thanks to advanced assisted reproductive technology and pre-implantation genetic testing (PGT-A ), a Single Embryo Transfer procedure is recommended by our physician to reduce the risks of twins, high-risk pregnancies, and miscarriages. 

Our IVF physician prefers to choose one good-quality embryo to transfer for a better pregnancy success rate. Not only does this reduce the number of risks to the surrogate and embryo (including the possibility of multiples), but it also reduces the number of wasted embryos, allowing the intended parents the opportunity to have more options if they choose to in the future.

Can an embryo split into twins?

The short answer is yes, but the chances are quite small. Just like with any pregnancy, a twin pregnancy can still happen. In IVF, the chance of this outcome is approximately one out of 100 transfers. 

Although the root cause for this is still unknown, we do know that during an IVF transfer, the blastocyst, or developing embryo, can collapse in on itself. When this happens, sometimes it can cause the inner cell mass to split into two. The two inner cell masses lead to the development of twins. Again, this is not a common event, but there is always a small risk during the procedure.

How does an embryo split affect intended parents and surrogates?

As with any major news, receiving notice that you are now having twins could be quite a shock to all parties, and it is normal that you will need to take some time to accept this fact. Everyone will react in their own way, but there are many things that should be taken into account. 

For example, there are additional costs and risks associated with a twin gestational surrogacy journey that would not have been present initially. It is crucial for intended parents to communicate to their surrogate about all scenarios prior to the embryo transfer and determine what both parties are comfortable with, so both parties are prepared for all possible situations. 

It is important to know that, unlike a multiple embryo transfer, twins that result from a single split embryo transfer often cannot be reduced. Because identical twins will most likely share a placenta, it is usually impossible to remove one fetus to give the other the best chance of a healthy birth. Most IVF specialists will not recommend the reduction of the embryos.  

Either the surrogate will need to carry both fetuses to term, or the pregnancy will be terminated in hopes of a successful singleton pregnancy on the next attempt. Naturally, these are truly complicated, emotional conversations to have. This is why your surrogacy contracts are very important; the contract will address situations like this ahead of time and lay out a clear path moving forward in a legal capacity.

With all pregnancies, there is always a chance that unforeseen complications could arise, and those risks only increase with twin pregnancies. For example, a twin pregnancy can increase the risk of: 

  • Pre-term labor
  • Low birth weight
  • Preeclampsia
  • Gestational diabetes
  • Cesarean-section
  • Placenta abruption 

While a surrogate is aware of the chance of a twin pregnancy occurring, and all parties have come to an agreement regarding that occurrence before embryo implantation, these unlikely risks are important to be aware of. If you choose to move forward with a twin pregnancy, you will need to communicate with your surrogate to make sure that she is willing to accept these risks, and you will need to pay for additional costs as your contract states.

Added costs of twins

When it comes to twin or multiple pregnancies, there are a few areas where costs for intended parents will increase. During gestation, there is a fee per additional fetus, and the surrogate’s monthly allowance will also increase. Medical fees can also be increased due to additional check-ups to ensure both the surrogate and babies are healthy with the increased risk of twin pregnancy, along with additional hospital fees for multiple births and aftercare for the babies.

Reduce IVF risk with an advanced IVF clinic

Of course, choosing an IVF clinic that uses best practices reduces the risk of complications. Turn your dreams into reality with PFCLA, where your odds of taking home a baby after one transfer are more than 40% higher than the average US IVF clinic. Click here to get started.

Note: This is not intended to be a substitute for professional medical advice, diagnosis or treatment. Information provided is for general educational purposes only and is subject to change without notice. Speak to your doctor directly with any questions you may have regarding a medical condition. Any information contained herein does not replace any care plan as determined by a physician. 

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