One of the many decisions intended parents face in a surrogacy journey is the number of embryos to transfer if more than one is available. Many factors have to be considered, including maximizing the chance for pregnancy, the health and safety of the gestational carrier, and, of course, the health and safety of the pregnancy and child(ren). There may also be a desire by intended parents to have more than one child. Due to the significant costs of GC cycles, there may be pressure to try to achieve this goal within one surrogacy journey.
The decision of whether to transfer one or two embryos during an IVF cycle is a complex one, with both potential benefits and risks. While a double embryo transfer may increase the chance of pregnancy, it also significantly increases the risk of a multiple pregnancy, which carries its own set of complications.
This blog post will explore the data and guidelines surrounding single embryo transfer (SET) and double embryo transfer (DET), helping you understand the factors to consider when making this important decision.
SET vs DET Understanding the Difference
- Single Embryo Transfer (SET): As the name implies, SET involves transferring a single, high-quality embryo into the uterus during an IVF cycle. This method has become increasingly common in recent years due to improved embryo selection techniques and concerns about the risks associated with multiple pregnancies.
- Double Embryo Transfer (DET): DET involves transferring two embryos during a single IVF cycle. This method may be considered in certain situations, such as for patients with poor embryo quality/low potential for implantation, a history of failed IVF cycles, or those who have a limited number of embryos available.
Patient Autonomy and Evidence-Based Decision Making
Choosing between single embryo transfer (SET) and double embryo transfer (DET) is a deeply personal decision with significant implications. While respecting individual autonomy is paramount, the physician’s ethical responsibility to “do no harm” adds another layer of complexity.
On the one hand, patient autonomy empowers individuals to make informed choices about their healthcare, including reproductive decisions. Understanding the risks and benefits of both SET and DET through open dialogue with their doctor is crucial for patients to make decisions aligned with their personal values and desired outcomes.
However, a physician’s responsibility extends beyond simply presenting information. They have an ethical obligation to guide patients towards safe and evidence-based practices. In situations where SET offers comparable pregnancy rates to DET  but with significantly reduced risks of multiple pregnancies and their associated complications, the physician must advocate for prioritizing the safer option.
Where applicable, published/peer-reviewed data from the medical literature should be used to weigh relative risks and benefits. Additionally, guidelines from pertinent medical societies can provide guidance based on expert and consensus opinions.
Balancing these two principles requires open communication and a shared commitment to evidence-based decision-making. Patients deserve clear and comprehensive information about the risks and benefits of each option, along with the physician’s expert guidance based on current medical knowledge. By working together, patients and physicians can navigate this complex decision with clarity and prioritize the safest path to achieving a healthy pregnancy.
Risks and Success Rates of Single and Double Embryo Transfer
The choice between transferring one or two embryos during an IVF cycle (single embryo transfer or SET vs. double embryo transfer or DET) requires careful consideration of both potential benefits and risks.
While DET may seem like a faster route to pregnancy with the potential for twins, the data paints a clear picture: it significantly increases the risk of multiple pregnancies , which carry significant risks for both the pregnant woman and the babies. The risks to the gestational carrier include hypertension, c-section, postpartum hemorrhage, and loss of life. The risk of transferring two embryos is also associated with prematurity, low birth weight, and potential complications during delivery with increased risk to the newborn.
Recent studies offer encouraging news for those considering SET. The evidence is clear that the use of SET, with or without the use of PGT, increases the safety of IVF for gestational carriers  by significantly reducing the risk of a multiple pregnancy. It also results in excellent live birth rates of approximately 50% in gestational carrier cycles with donor egg. This means that you can increase your chances of a healthy pregnancy without exposing your gestational carrier and your baby to the increased risks associated with multiple pregnancies.
Leading medical organizations like the American Society for Reproductive Medicine (ASRM) advocate for prioritizing SET in most cases. This recommendation is based on the clear evidence of the significant risks associated with multiple pregnancies and the comparable success rates achieved with SET.
These guidelines, which focus on the number of embryos to transfer , consider various factors, including the age of the patient or egg donor, the stage of embryo development, and whether preimplantation genetic testing for aneuploidy (PGT-A) has been conducted. For gestational carrier cycles, ASRM strongly recommends single-embryo transfers, emphasizing adherence to age-related limits based on the age of the egg provider to minimize health risks for both the carrier and the fetuses.
ASRM’s ethical stance  supports single embryo transfer, especially in gestational carrier cycles, to maximize pregnancy chances while minimizing the risks of multiple gestations, which can lead to complications for both the pregnant woman and the fetuses. The decision on the number of embryos to transfer involves a careful evaluation of various factors, including embryo quality, egg and sperm sources, and societal guidelines. Each case requires a thoughtful discussion among the clinical team, the gestational carrier, and the intended parents, with a general preference for single embryo transfer to ensure safety and minimize risks.
Balancing Costs, Risks, and Ethics in Single vs. Double Embryo Transfer
In surrogacy, the request for a double embryo transfer (DET) is sometimes fueled by a desire for twins and the potential cost savings of only one surrogacy journey. While this understandable desire is valid, the ethical and medical landscape presents complexities that must be considered.
On the one hand, a physician’s duty is to minimize risk and ensure optimal outcomes for both the surrogate and the future child. The data is clear: DET significantly increases the risk of multiple pregnancies, which can lead to complications for both pregnant woman and babies.
However, patient autonomy is paramount, and individuals have the right to make informed decisions based on their individual circumstances and values. Some may prioritize cost savings and the desire for twins, while others may value minimizing risk and ensuring a safe pregnancy.
Navigating this complex ethical landscape requires a nuanced approach:
- Transparency and communication: Physicians must provide clear information about the risks and benefits of both SET and DET, ensuring patients understand the potential consequences of their choices.
- Shared decision-making: A collaborative approach allows patients to voice their preferences and concerns while receiving expert guidance based on current medical knowledge and ethical considerations.
- Respecting patient autonomy: While prioritizing safety, physicians should acknowledge and respect patient autonomy within the boundaries of responsible medical practice.
- Individualized care: Recognizing the unique circumstances of each patient and tailoring the discussion to their specific needs and values.
Ultimately, the goal is to achieve a shared understanding that balances patient preferences with the ethical obligation to provide safe and effective care. This requires open communication, respect, and a commitment to evidence-based medicine. By working together, patients and physicians can navigate this complex decision with clarity and prioritize the best course of action for everyone involved.
Multiple Pregnancy Risks and Outcomes: Understanding the Data
The choice between single embryo transfer (SET) and double embryo transfer (DET) during an IVF cycle hinges on understanding the potential risks and outcomes of multiple pregnancies. While the desire for twins may seem appealing, the reality of multiple pregnancies presents significant risks that can impact both the pregnant woman and the babies.
Here’s a closer look at the data:
Increased Risk of Multiple Pregnancy:
- DET significantly increases the chance of a multiple pregnancy, most commonly twins.
- While twins may seem like a bonus, multiple pregnancies carry a higher risk of complications for both the pregnant woman and the babies.
Potential Risks for the Gestational Carrier:
- Premature labor and birth
- Preeclampsia and gestational hypertension
- Placenta previa or abruption
- Postpartum hemorrhage
Potential Risks for the Babies:
- Low birth weight
- Preterm birth
- Twin-to-twin transfusion syndrome
- Birth defects
Making an Informed Choice
The decision between SET and DET is a personal one, and several factors should be considered:
- Discuss the risks and benefits of both options with your doctor.
- Consider your individual preferences and desired family size.
- Weigh the risks of multiple pregnancies against the potential benefits of twins.
- Make a decision that aligns with your values and priorities.
Remember, a successful surrogacy journey isn’t just about getting pregnant; it’s about ensuring the safest possible outcome for everyone involved. By weighing the risks and benefits carefully and making an informed decision, you can increase your chances of achieving a healthy and successful pregnancy.
About Dr. Laurence Udoff
Dr. Laurence Udoff is a distinguished fertility specialist at GIVF Fertility, renowned for his expertise and compassionate approach to reproductive medicine. With a career dedicated to helping individuals and couples achieve their dream of parenthood, Dr. Udoff is a trusted expert in the field of fertility and reproductive health.
Dr. Udoff’s medical journey began with his graduation from the University of Maryland School of Medicine, followed by a residency in Obstetrics and Gynecology at the University of Maryland Medical System. He further honed his skills and knowledge with a fellowship in Reproductive Endocrinology and Infertility at the University of Maryland as well as the University of Utah.
At GIVF Fertility, Dr. Udoff specializes in a range of fertility treatments and services, including in vitro fertilization (IVF), intrauterine insemination (IUI), fertility preservation and pre-implantation genetic diagnosis. He is deeply committed to providing personalized care, understanding that each patient’s journey is unique.
Dr. Udoff’s dedication to his field is evident in his active involvement in research and education. He regularly contributes to scientific publications and stays abreast of the latest advancements in reproductive technology to ensure his patients receive the most effective treatments available.
For more information about Dr. Laurence Udoff and his services at GIVF Fertility, please visit GIVF Fertility.
 Kamath, M.S. et al. (2020) Number of embryos for transfer following in vitro fertilisation or intra-cytoplasmic sperm injection, The Cochrane database of systematic reviews. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8094586/ (Accessed: 11 December 2023).
 Namath A; Jahandideh S; Devine K; O’Brien JE; Stillman RJ; (2021) Gestational carrier pregnancy outcomes from frozen embryo transfer depending on the number of embryos transferred and Preimplantation Genetic Testing: A retrospective analysis, Fertility and sterility. Available at: https://pubmed.ncbi.nlm.nih.gov/33691932/ (Accessed: 11 December 2023).
 Makhijani, R. et al. (2021) Reduction in multiple pregnancy rate in donor oocyte-recipient gestational carrier (GC) in vitro fertilization (IVF) cycles in the USA with single-embryo transfer and preimplantation genetic testing, Journal of assisted reproduction and genetics. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8266963/ (Accessed: 11 December 2023).
 American Society for Reproductive Medicine (2021) Guidance on the limits to the number of embryos to transfer: A …, Guidance on the limits to the number of embryos to transfer: a committee opinion (2021) . Available at: https://www.asrm.org/practice-guidance/practice-committee-documents/guidance-on-the-limits-to-the-number-of-embryos-to-transfer-a—committee-opinion-2021/ (Accessed: 11 December 2023).
 Ethics Committee of the American Society for Reproductive Medicine (2018) Consideration of the gestational carrier: An ethics committee opinion, Fertility and sterility. Available at: https://pubmed.ncbi.nlm.nih.gov/30396538/ (Accessed: 11 December 2023).