How Many Embryos Should You Transfer?

One of the biggest decisions during IVF is also one of the most common questions patients ask. If transferring  one embryo gives you a chance of pregnancy, wouldn't transferring two increase those chances even more? It sounds like a simple choice, but there is much more to consider than the numbers alone. The goal of IVF  is not simply to achieve pregnancy. It is to achieve the healthiest pregnancy possible, and that is why the  number of embryos transferred is always carefully considered. 

Why One Embryo Is Often Recommended

Years ago, transferring two or more embryos was more common, partly because embryo selection and  freezing techniques were not as advanced as they are today. As IVF has developed, so has the understanding  that transferring a single high-quality embryo can offer an excellent chance of pregnancy while reducing the  risk of multiple pregnancies. (Source: Oxford Academic)  

Twins may sound appealing to some couples, especially after a long fertility journey, but carrying more than  one baby also increases the risk of complications for both the mother and the babies. Premature birth, low  birth weight, and pregnancy complications are all more common in multiple pregnancies. For that reason, many fertility clinics now recommend transferring one embryo whenever it is considered  the safest and most appropriate option. 

When Two Embryos May Be Considered

That does not mean every patient receives the same recommendation. The decision depends on several  factors, including age, embryo quality, previous IVF attempts, medical history, and how the embryos have  developed. For some patients, transferring two embryos may be discussed if the expected chance of success  with a single embryo is lower. (Source: Science Direct) Rather than following the same approach for  everyone, fertility specialists look at the whole picture before making a recommendation. What is right for  one patient may not be the best option for another. This is why treatment plans are personalized instead of  based on a single rule. 

More Embryos Do Not Always Mean Better Chances

It is understandable to think that transferring more embryos automatically increases the likelihood of  pregnancy. In reality, it is not quite that straightforward. 

A successful IVF cycle depends on many factors working together, including embryo quality, uterine health,  and the success of implantation. Adding another embryo does not guarantee a better outcome, but it can  increase the likelihood of a twin pregnancy if both embryos implant. 

For many patients, hearing this comes as a surprise. The focus naturally tends to be on becoming pregnant,  while the importance of achieving a healthy singleton pregnancy is not always something people think about  at the beginning of treatment. 

A Decision Made Together

Choosing how many embryos to transfer is not simply a medical decision made by the clinic. It is usually a  conversation between the patient and the fertility team, taking into account medical recommendations as  well as personal circumstances. (Source: BMJ Open) Asking questions, discussing concerns, and  understanding the reasons behind the recommendation can help patients feel more confident about the  treatment plan. 

Sources:  

Oxford Academic - https://academic.oup.com/humrep/article/39/4/647/7607249 Science Direct - https://www.sciencedirect.com/science/article/pii/S001502822100563X BMJ Open - https://bmjopen.bmj.com/content/6/5/e010894