Blastocyst Transfer: An Assisted Reproductive Technology in the Los Angeles Area
Blastocyst transfer is at the forefront of advances in fertility. Blastocysts are advanced embryos that have a higher chance (per embryo) of implantation than do earlier-stage embryos. Developing embryos are allowed to grow undisturbed for five days until they reach the blastocyst stage of development. Blastocyst transfer increases the rate of pregnancy while decreasing the risk of multiple pregnancy. Blastocyst transfer is an advanced assisted reproductive technology used at the Los Angeles-based Southern California Reproductive Center to help many couples become parents.
What is "blastocyst transfer"?
Blastocyst transfer is a new assisted reproductive technology that has been incorporated with in vitro fertilization (IVF) treatment to increase pregnancy rates while simultaneously decreasing the risk of multiple pregnancies. Researchers in Australia pioneered this technique to increase pregnancy rates, and have reported almost double the rate of pregnancy while virtually eliminating the risk of high-order multiple pregnancies such as triplets or quadruplets. Blastocyst transfer at our Los Angeles-area offices in Beverly Hills, Santa Barbara, Valencia, and Ventura has been a very effective addition to our array of available infertility treatments.
back to top
What is a blastocyst?
By definition, a blastocyst is a highly differentiated, highly developed embryo that is ready to attach to the uterine wall. This attaching is also known as "implantation."
With pregnancies that are conceived under natural circumstances, the ovary follicle releases the egg, whereupon it is picked up by the fallopian tube and subsequently fertilized by the sperm. The resulting embryo begins as a single cell that must develop and differentiate to the point that it can attach itself to the uterine wall and establish a direct connection to the mother's blood stream.
Embryonic division progresses from one cell to two, four, eight, sixteen cells, etc., until several hundred cells have developed and the resulting embryo, now a blastocyst, can implant itself in the uterine wall. This occurs five to six days after ovulation. "Blastocyst" is a descriptive term that identifies the developmental stage of the embryo. The embryo spontaneously "hatches" from its shell, or zona pellucida, at the blastocyst stage just prior to implantation.
back to top
Why are blastocysts so important in IVF?
The key characteristic of the blastocyst is that it has reached the point where the developing baby's own genes have been activated and take over the remainder of the development. This is known as "genomic activation," and since genes are the chemical codes that make us unique individuals, genomic activation is the key point at which a unique individual results from conception.
As babies, each of us is a genetic mixture of the genes of our mother and father — unique and different from our parents and siblings. In its early growth stage, the embryo receives all of its energy and chemical makeup needed for successful cell division from the mother's egg. Development past the third to fourth day requires that the embryo activate its own genes to continue to produce further cell division and differentiation.
While this critical biological process appears to be elegantly simple, it does not take place as easily as it appears. Approximately one-third of embryos have the capability of successfully activating their own genes and developing into a blastocyst. When an embryo does reach the blastocyst stage, the natural message is that it is a biologically healthier embryo fit enough to successfully implant in the uterus and continue development through to a full-term pregnancy and delivery of a normal, healthy baby. The fertility specialists at the Southern California Reproductive Center have years of experience performing blastocyst transfer as an assisted reproductive technology at our Los Angeles-area clinics.
back to top
Why is blastocyst transfer new to the field of IVF?
Researchers have known the physiology of embryo growth for many years, and they have been aware that conventional IVF technology transferred the embryos into the uterus earlier than was normal by natural physiology. By contrast, in naturally occurring pregnancies, the embryo remains in the fallopian tube, growing and dividing for several days, and does not reach the uterus until after three to four days of development. Tubal transfer procedures such as gamete intrafallopian transfer (GIFT) and zygote intrafallopian transfer (ZIFT) were developed based on this fact.
In the early stages of the development of IVF technology, researchers were not able to develop lab culture mediums and incubation techniques that would allow the necessary number of embryos to develop into blastocysts. In fact, recent research has shown that the developing embryo requires changing nutritional and metabolic support as it leaves the fallopian tube and enters the uterus. Since this discovery, IVF technology has developed "sequential culture media" which change according to the changing needs of the developing embryo. This breakthrough in the fundamental IVF technique has allowed embryos to successfully progress to the blastocyst transfer stage.
How blastocyst culturing helps couples achieve pregnancy
In conventional IVF, embryos are grown for only two to three days before being transferred back into the uterus. At this stage of development, the embryo has between four and eight cells inside the shell or zona pellucida, and, they must continue to develop inside the uterus for four to five additional days before they become blastocyst embryos that are ready and capable of being implanted.
If, during an IVF cycle, a couple produces many embryos, it cannot be determined which embryos have the capacity to grow into a blastocyst and which do not — and this is true regardless of the skill level of the embryologist. Thus, selecting a group of embryos for uterine replacement on day two or three after ovulation is too early for any assurance of a successful implant. Therefore, even though the risk for multiple pregnancy is increased, the conventional IVF procedure usually involves the transfer of four or five embryos in order to increase the chances for at least one successful pregnancy.
Now, based on the most current IVF research and development, the embryos are kept in the IVF lab for an additional two to three days, allowing blastocyst development and the capability to choose the best embryos for uterine replacement. This gives rise to some very positive news for IVF patients. You can learn more about blastocyst transfer and assisted reproductive technology at our Los Angeles-area offices in Beverly Hills, Ventura, Valencia, and Santa Barbara.
back to top
Reducing the risk of multiple births
Allowing the embryos more time to develop in the IVF lab means that the embryologist can see which ones are naturally the best for transfer, so that only those few embryos that appear to have the greatest opportunity for a successful implant can be chosen. This means that typically only two blastocyst embryos are transferred, with pregnancy rates of greater than 50 percent in patients who develop healthy blastocysts. This virtually eliminates the risk of high-order multiple pregnancies such as triplets or quadruplets, and it has allowed us to provide a whole new approach to counseling couples concerned about multiple pregnancies.
Furthermore, this technology has very positive implications in situations such as egg donation where, typically, a large number of high-quality embryos are available. In fact, blastocyst transfer as an assisted reproductive technology at our Los Angeles-area clinics has increased success rates in egg donation programs to more than 80 percent per transfer.
Blastocyst transfer is not for everyone
Culturing embryos to the blastocyst transfer stage is highly dependent on the quality and capability of the lab. Our embryology staff's experience and high level of blastocyst transfer technical expertise are key to a successful team approach, wherein the IVF lab works closely with you and your fertility doctor to maximize the opportunity for a successful pregnancy while minimizing the risk of multiple pregnancies.
However, it must be noted that a blastocyst culture cannot transform a poor embryo into a good embryo. For couples who cannot naturally produce a high-quality embryo, a blastocyst culture allows the IVF team to observe and analyze how these embryos grow, making possible a potential for diagnosis as to why previous IVF treatments failed. Embryos that do not develop normally are eliminated from embryo transfer, and, in these cases the IVF lab provides highly valuable information for couples who might need to consider other options for creating a family.
Schedule an Appointment to Learn about Blastocyst Transfer
If you suspect that you might be having trouble producing viable embryos, or suffer from male or female infertility, contact the Southern California Reproductive Center for blastocyst transfer and other assisted reproductive technology options at our Los Angeles-area offices in Beverly Hills , Santa Barbara, Valencia, and Ventura.
back to top
