Single-Selection Success

In vitro fertilization (IVF) often includes a crucial decision regarding the number of embryos to transfer. Advances in reproductive medicine have improved success rates, making single embryo transfer (SET) a viable option for many patients. While multiple embryo transfer (MET), when 2 or more embryos are transferred during a single cycle, increases the chance of implantation, the approach also raises health risks. Understanding the risks and benefits of SET and MET can help individuals decide how many embryos to transfer.

Success rates and health considerations

Single embryo transfer offers a high chance of success, particularly for individuals using high-quality embryos. Studies indicate that SET results in live birth rates of 50-60% per cycle for patients under 35. Transferring multiple embryos can improve implantation rates but does not always increase the probability of a successful pregnancy. Transferring more than a single embryo often leads to multiple gestations, which come with additional health risks. Advances in embryo freezing allow for subsequent transfers if the first attempt is unsuccessful.

Risks associated with multiples

A significant concern with MET is the increased likelihood of twins, triplets, or higher-order multiples. Multiple pregnancies are linked to premature birth, low birth weight, and complications such as gestational diabetes. Research shows that nearly 60% of twin pregnancies result in preterm delivery, putting the baby at increased risk of health complications. Even if the babies are delivered at term, neonatal intensive care unit (NICU) admissions occur more frequently in multiples. For couples prioritizing maternal and fetal safety, SET may provide a safer outcome.

Benefits of a single embryo transfer

Opting for SET minimizes the risk of pregnancy complications while maintaining strong success rates. A single, high-quality embryo has a strong chance of implantation. If the embryo transfer is successful, there will be fewer complications during pregnancy, as well as labor and delivery. Studies confirm that singleton births from IVF have outcomes comparable to naturally conceived pregnancies, and during IVF, many fertility doctors now recommend this approach.

Individual factors to consider

Although SET is the preferred approach, maternal age, embryo quality, and previous IVF outcomes will influence the best transfer strategy. Younger patients with high-quality embryos often achieve success with SET. For older women with previous failed cycles or lower-quality embryos, MET may provide a higher chance of implantation. Each IVF journey is unique, requiring a personalized approach based on medical history. A fertility specialist can provide guidance on the most appropriate transfer option.

SET vs MET

Although personal preferences will be taken into consideration, most doctors will recommend a single embryo transfer during IVF to lower the risk of complications and increase the chances of success. Patients who want a healthy baby should feel reassured that SET is the safer choice.