“With the help of CCS, it is possible to accurately identify the healthiest embryos and safely freeze (vitrify) them, using advanced cryopreservation techniques,” he said.
San Francisco, CA (PRWEB) May 19, 2015
Unprecedented high pregnancy rates combined with low pregnancy risks: That’s the promise of elective single embryo transfer (eSET), when combined with comprehensive chromosome screening (CCS) and other technologies. Today, with their new program, Pacific Fertility Center (PFC) is delivering on that promise, achieving pregnancy rates ranging from 50–75 percent per transfer and multiple gestation rates of just 2 percent—much lower than the 20–30 percent typical of traditional in vitro fertilization (IVF).
Behind eSET’s success
“Technology tools enabling eSET have vastly improved,” said Philip E. Chenette, MD, director of PFC’s Fertility Preservation Program. “With the help of CCS, it is possible to accurately identify the healthiest embryos and safely freeze (vitrify) them, using advanced cryopreservation techniques,” he said. “Now, single embryo transfer is clearly the best choice for building a healthy family.”
However, successful eSET requires:
- Proper screening of patients
- Good stimulation protocols to get the maximum number of mature eggs
- A lab that understands fertilization well and can get eggs fertilized
- Special environmental conditions and medium to allow culture of embryos to Day 5,6, or 7 (the blastocyst stage)
- Skilled staff capable of overcoming steep learning curves
Leaders in eSET
Early adoption of technology helped put PFC at the vanguard of eSET. However, long before the development of technology such as CCS, PFC “cut its teeth” on eSET with a specific population: Those achieving pregnancy through egg donation—usually women age 40 and older. Their risk of multiple gestation was higher because they received egg donations from women in their mid-20s, and eggs from younger women produce very high implantation rates. “We began using eSET to lower the risk of multiple gestation,” said Dr. Chenette.
“Then we started thinking, ‘We’re doing so well in the egg-donor world, why can’t we extend this to women using their own eggs?’” said Dr. Chenette. Today, about 75 percent of all transfers are single-embryo transfers, he added, explaining that the ultimate decision is up to the patient.
PFC continues to present abstracts on eSET,1 to encourage colleagues, and to help advance the field, which is now shifting many toward this practice. “We continue to be one of the leaders in the country with single embryo transfer,” said Dr. Chenette.
Benefits of eSET
In women under age 35, PFC mainly uses eSET. In women 43 and older, PFC recommends eSET, but multiple gestation is less of a concern due to production of fewer embryos. Women who benefit the most are ages 35–42, said Dr. Chenette. The guidelines allow them to transfer 2–4 embryos, so they will see a big reduction in multiple gestation using eSET after CCS.
Although PFC does not mandate single embryo transfers, its physicians and staff counsel patients on eSET’s many benefits:
- First, eSET lowers the risk of multiple gestation, and related serious risks such as low birth weight, birth defects, cerebral palsy, and fetal or maternal death, said Dr. Chenette. “Unfortunately, there’s a bias among many patients that twins are a good thing, but what gets lost here is that twins increase risks over a singleton pregnancy by about 500 percent.”
- Second, CCS combined with eSET lowers the risk of miscarriage by about 20 percent. Minimizing miscarriage in older women is particularly important, said Dr. Chenette, because these women have no time to lose. A miscarriage can delay the next pregnancy attempt by 4 to 5 months, he said, during which time there can be a substantial decline in fertility rates.
- Third, CCS combined with eSET lowers the risk of Down syndrome by 1,000 percent, said Dr. Chenette, and prevents the need for terminating a pregnancy if later discovered with prenatal screening.
"Transferring multiple embryos and having more than one child at a time may sound efficient. But freezing and transferring one embryo at a time has become a much more efficient way to create a healthy family," said Dr. Chenette. “We also think it is cheaper over the long haul to do single embryo transfer.”
There are, however, slight risks associated with vitrification and CCS: a 5 percent rate of lost embryos with vitrification, as well as a 1–3 percent false positive test result (diagnosing a problem that isn’t really there) and a less than 1 percent false negative test result (missing a problem that’s present) with CCS.
A holistic approach
For Dr. Chenette, eSET is an essential part of PFC’s holistic approach to building healthy families—just as good nutrition, stress reduction, and relationship counseling are all ways PFC also promotes a healthy pregnancy.
And just as most parents wouldn’t think of heading home from the hospital without putting their newborn in a safe car seat, they can also take steps earlier to create a safer pregnancy: By choosing single embryo transfer, parents can start a pregnancy off right, helping minimize the unlikely—but extremely serious—risks linked with transferring multiple embryos.
1. Chenette P, Ryan I, Givens C, Fischer E, Conaghan J. Toward a program of single embryo transfer: reducing multiple gestation risk using CCS. Fertility and Sterility, Sept. 2014. Vol. 102, Issue 3, e58–e59.
About Pacific Fertility Center
Pacific Fertility Center is an international destination for male and female fertility treatment and care. It provides an extensive array of fertility treatment options ranging from intrauterine insemination (IUI), intracytoplasmic sperm injection (ICSI) and in vitro fertilization(IVF) to cutting-edge technology such as vitrification and genetic testing of embryos. For more information: http://www.pacificfertilitycenter.com.
Renee H. Scudder, MS
Pacific Fertility Center
55 Francisco Street, Fifth Floor
San Francisco, CA 94133