By Dr. Mary Hinckley
I often hear patients say “I just want a healthy baby.” But when it comes time to do the embryo transfer in an IVF cycle, the rubber meets the road. The patient or couple must decide how many embryos to transfer.
This is not always an easy decision for the patients or the doctor. Many factors are considered and good communication is essential. Some of the key factors include:
- Patient age
- Embryo quality
- Fertility history
- Uterine issues or abnormalities
- Prior pregnancy complications (or successes )
- General Health issues ( blood pressure, diabetes, heart disease)
- Financial issues
- Emotional state
When IVF first started more than 30 years ago, success rates were so low that multiple embryos were transferred in order to achieve just 1 baby. Likely, the embryology culture media and incubator conditions hampered development of normal embryos. Uterine preparation and embryo transfer technique had also not been optimized and so a healthy implantation was still a struggle. But many things have improved and now patients are encouraged to consider an elective single embryo transfer.
As an aside, the term “elective” is still hard to define. Did the medical team strongly encourage it due to medical risks? Did the patient desire it even against medical advice since twins would be too stressful, despite having poorer quality embryos or an advanced age? Or was it truly elective in its most pure form, e.g. there were several good quality embryo to choose from and the patient and doctor both felt it was in the patient’s best interest to transfer only 1 to improve the odds of a singleton conception?
In 2003, collected data revealed that only 0.7% of embryo transfers were elective single embryo transfers in women <35 years and 0.4% in patients 35-37. Recent data from 2009 shows that 7.2% of IVF cycles had an eSET in women under age 35 and 4% in women 35-37.
At RSC, approximately 15 % of women under 38 years old chose to have an eSET (double the national average!! We also had 21% of egg donation cycles choose eSET and performed 102 eSETs in total of 612 cycles (fresh and frozen.)
While it still may be true that transferring more than 1 embryo will result in a higher pregnancy rate, it also can bring about more risks and complications. By choosing to cryopreserve that 2nd (or more) embryo, you will have a slightly lower pregnancy rate per cycle, but higher chance of a healthy pregnancy. The costs involved in transferring that second embryo at a later date may be from 0-$3,500. What is good health of your child worth to you?
At RSC we are striving to produce healthy children. Evidence based studies show that there are fewer complications with a singleton pregnancy compared to twins. Our philosophy is to educate the patients, even at the initial visit, as to the risks and benefits of transferring 1 or more embryos. We help patients think in the abstract about what their goals are and how to achieve them. We usually will develop with the patient a tentative plan for the number of embryo to transfer. We follow ASRM guidelines, but more importantly, our own more stringent statistics, which can help us better counsel patients about their odds of success based on age and embryo quality. We often will take embryos to the blastocyst stage in order to choose the strongest embryos and thereby be able to transfer fewer embryos to obtain the same pregnancy rate (for example, 2 day-3 embryos are often the equivalent of 1 day-5 blastocyst embryo.) On the day of embryo transfer, the physician will speak with the embryologist and review the embryo quality. The physician will then talk with the patient to offer help in making the final decision. We strongly encourage patients (especially if <38 years) to accept only 1 embryo if the embryo quality is 3BB or better and there are extra embryos to freeze that day.
A short note on the grading system:
Day 3 (an 8 cell grade 1 embryo is the best)
- Embryos get a cell count (usually 1-10 cells, 8 is the perfect number)
- Embryos get a numerical grade ( 1-4 with 1 and 2 being the best) which relates to the roundness and equality of cells and grades fragmentation
Day 5/6 (a 5AA embryo is the best)
- Embryos get a number that represents the expansion size (1-5). Bigger is better (5).
- Embryos get a first letter that indicates quality of the cells destined to become the baby
- Embryos get a second letter that indicates quality of the cells destined to become the placenta (A is best)
Emotional stress often pushes patients to make decisions out of desperation. Many patients want so badly to be pregnant that they do not think about the possible downside of getting “too pregnant.” Many feel that they can make up for lost time by having twins. And often, IVF is so financially draining that patients know they may only have 1 chance at a fresh cycle and want to optimize the pregnancy rate, forgetting that the delivery rate is the most important statistic. Some insurances are now mandating the number of embryos patients can transfer. Initiatives within the American Society of Reproductive Medicine are making the benefits of eSET more widely known and using peer pressure to urge some clinics to increase the number of eSETs they do. Regardless of these pressures, the doctors at RSC will continue to try to educate patients to make the healthiest decisions for building families.
Dr. Mary Hinckley is a leading Reproductive Endocrinology and Infertility specialist at the Reproductive Science Center of the San Francisco Bay Area. She has extensively published articles in peer-reviewed journals on blastocyst transfer, avoiding triplet pregnancies, monozygotic twinning, operative hysteroscopy, correction of uterine anomalies, and biochemical pathways involved in ovulation and fertilization. She serves as a member of the Society for Reproductive Endocrinologists, the Christian Medical and Dental Society and the American Society for Reproductive Medicine. Her areas of interest include laparoscopic surgery, premature ovarian failure, oocyte freezing, and recurrent pregnancy loss.
