For many couples facing the heartache of infertility, the journey through assisted reproductive technologies (ART) is often a race against time and a gamble with hope. The primary goal is simple: a healthy pregnancy. However, a critical tension exists between the desire to maximize the chances of success and the medical necessity of minimizing risks. At the center of this debate is the decision between a single versus double embryo transfer.
While the instinct to transfer multiple embryos to “increase the odds” is common among patients, clinical evidence suggests that this approach often introduces significant complications without providing a proportional benefit. A recent comprehensive evaluation of registry data has shed new light on the risks associated with this practice, emphasizing a pressing need for better patient education and a shift toward safer transfer protocols.
A study published in Deutsches Ärzteblatt International (2026) analyzed over 22,000 treatment cycles to determine the impact of embryo transfer numbers on pregnancy outcomes. The findings underscore a persistent challenge in the field of reproductive medicine: the high incidence of multiple pregnancies and the subsequent health risks for both the mother and the children.
The Risk of Multiple Pregnancies in ART
The use of assisted reproductive technologies has grown globally over the last several decades, offering a lifeline to millions. However, this growth has been accompanied by a notable increase in multiple pregnancies—pregnancies involving twins, triplets, or more. According to data from the German In-vitro-Fertilisations (IVF) Register, the risk of multiple pregnancies during the study’s evaluation period ranged between 12% and 19%.
This elevated risk is primarily attributed to the common clinical practice of transferring more than one embryo during a single cycle. While the intent is to ensure at least one embryo implants, the result is frequently the simultaneous implantation of multiple embryos. The study indicates that the risk associated with these outcomes is significantly higher, noting an odds ratio (OR) of 1.47 [1.19. 1.81] regarding increased risks during pregnancy.
Medical professionals are increasingly advocating for elective single embryo transfer (e-SET) to mitigate these risks. By limiting the transfer to one high-quality embryo, clinicians can virtually eliminate the risk of multiple gestations while maintaining a viable path to a successful live birth.
The Clinical Toll: Premature Birth and Long-term Development
Multiple pregnancies are not merely a logistical challenge; they are high-risk medical events. The study highlights that multiple gestations are linked to increased risks for both the mother and the children. The most significant and frequent complication identified is premature birth.
Premature births create a cascade of medical requirements and potential lifelong challenges. Infants born prematurely often require intensive medical care immediately following birth. Beyond the neonatal period, these children face a heightened risk of long-term developmental disorders, which can impact their cognitive and physical growth.
For the mother, the physiological strain of carrying multiple fetuses increases the likelihood of pregnancy-related complications, such as gestational diabetes and preeclampsia. When the goal of infertility treatment is a healthy family, the introduction of these severe complications often outweighs the perceived benefit of transferring a second embryo.
Bridging the Gap in Patient Perceptions
One of the most striking findings of the registry evaluation is the disconnect between clinical reality and patient belief. Many couples underestimate the probability of having multiples and the serious complications that can follow during and after birth.
There is a widespread belief among patients that implanting multiple embryos significantly boosts their overall chances of achieving a successful pregnancy. However, the data suggests that this perception is often misplaced. The focus on the “chance of success” frequently overlooks the “quality of outcome,” where a single, healthy baby is the safest and most sustainable result.
This gap in understanding places a heavy burden on healthcare providers to provide transparent, evidence-based counseling. Ensuring that patients understand that more embryos do not necessarily mean a higher probability of a healthy, full-term pregnancy is essential for informed consent.
The evaluation of over 22,000 treatment cycles serves as a critical reminder that in reproductive medicine, “more” is not always “better.” The priority must shift toward the health of the mother and the long-term viability of the child.
Key Takeaways for Patients and Providers
- Multiple Pregnancy Rates: Data from the German IVF Register shows a 12% to 19% risk of multiple pregnancies in the analyzed period.
- Primary Cause: The practice of transferring multiple embryos is the lead driver of these high-risk pregnancies.
- Major Complication: Premature birth is a primary risk, often leading to intensive care needs and potential developmental disorders in children.
- Patient Misconception: Many couples incorrectly believe that transferring multiple embryos significantly increases their chances of a successful pregnancy.
- Clinical Recommendation: Prioritizing single embryo transfers can reduce maternal and neonatal risks without compromising the fundamental goal of parenthood.
As the field of ART continues to evolve, the move toward personalized medicine—where embryo selection is based on advanced screening and individual patient profiles—will likely further reduce the reliance on multiple transfers. For those currently navigating infertility treatments, the most important step is an open, honest dialogue with their reproductive endocrinologist about the trade-offs between transfer numbers and pregnancy safety.
Further updates on ART guidelines and registry data are expected as the Deutsches Ärzteblatt and associated medical boards continue to analyze long-term outcomes from these large-scale cohorts.
Do you have experience with e-SET or have questions about embryo transfer protocols? Share your thoughts in the comments below or share this article with others navigating the IVF journey.