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When undergoing in vitro fertilization (IVF), one of the most critical decisions you and your medical team will make is determining the number of embryos to transfer. This decision aims to maximize the chances of a successful pregnancy while minimizing the risk of multiple pregnancies, which can pose serious health risks to both the mother and babies. In this post, we'll explore the factors that influence this decision and the guidelines provided by the American Society for Reproductive Medicine (ASRM).

The Risks of Multiple Pregnancy

Multiple pregnancy is one of the most significant complications associated with fertility treatments like IVF. It can lead to serious health risks for both the pregnancy and the babies. To minimize this risk, the best approach is often to transfer only one embryo, a practice known as single embryo transfer (SET). Studies have shown that SET can achieve similar success rates to multiple embryo transfers while greatly reducing the risk of twin or higher-order pregnancies. 

If PGT is not performed, the ASRM provides recommendations on the number of embryos to transfer based on several factors:

1. Age: Women over 38 using their own eggs may be advised to transfer multiple embryos due to the increased likelihood of chromosomal abnormalities in their embryos.

2. Embryo Quality: High-quality embryos, as determined by preimplantation genetic testing (PGT), are more likely to result in a successful pregnancy with SET. To learn more about Orchid’s PGT services, refer to our recent guide Genetic Testing for Embryos.

3. Embryo Development Stage: The stage of embryo development at the time of transfer can also influence the decision.

4. Other Clinical Factors: Your medical team will consider your unique circumstances and health history when making their recommendation.

‍Age and Embryo Quality

For patients younger than 35 using PGT-tested embryos, single embryo transfer is highly recommended. These patients achieve similar singleton pregnancy rates whether one or two embryos are transferred. 

‍Embryo Splitting and Multiple Pregnancy

It's important to note that even with single embryo transfer, there is a small chance (less than 3%) of the embryo splitting, resulting in identical twins. When two embryos are transferred, there is also a less than 3% chance of one embryo splitting, potentially leading to a triplet pregnancy. In extremely rare cases, transferring two embryos that both split could result in quadruplets.

Deciding how many embryos to transfer during IVF is a complex process that requires careful consideration of multiple factors. Your medical team will work with you to create an individualized plan that balances the desire for a successful pregnancy with the risks associated with multiple pregnancies. By understanding the guidelines and factors involved, you can make an informed decision that aligns with your goals and priorities.

The content on this blog is for informational purposes only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always consult with a qualified healthcare provider before making any health-related decisions or implementing any medical information shared here.