By routinely practicing Single Embryo Transfer (SET), RMA has drastically reduced the risk for the mother and child.
Singleton babies conceived after SET at RMA have birth weights equivalent to babies conceived naturally (the majority of our babies weigh more than 2,500 grams), term delivery rates similar to babies conceived naturally, and spend far fewer days in the Neonatal Intensive Care Unit (NICU) than IVF twins.
The very existence of SET is a measure of success. In greater than 95 percent of cases at RMA, doctors are able to transfer just one embryo at a time because of a truly groundbreaking embryo screening test using targeted amplification and high depth next generation sequencing. This test, called Comprehensive Chromosome Screening (CCS), gives doctors confidence about the chromosomal composition of the embryo, which helps to improve embryo selection for transfer. Achieving this confidence was a years-long research effort pioneered by the researchers at RMA.
The first step in the effort was creating the ability to grow embryos longer in the laboratory, until they reached the blastocyst stage of development. Many areas of this research focused on culturing embryos in a way that mimicked the way embryos grow in the body. This research, which studied the way oxygen levels, temperatures, and other factors of embryo culture affected IVF pregnancy rates, allowed RMA doctors to identify the most conducive growing media for embryos, and grow embryos to day 5, 6 or 7, when they reach the blastocyst stage.
At the blastocyst stage, embryos are big and strong enough (containing several hundred cells) to be biopsied, a procedure which is necessary to check whether they are chromosomally normal or not prior to implantation. According to RMA’s own research, a blastocyst stage biopsy was less harmful to an embryo than a day 3 biopsy, giving doctors the confidence to safely perform biopsies at the blastocyst stage. This seminal piece of research revolutionized the field.
Next came another crucial phase: the biopsy testing system. Before embryo biopsy, doctors transferred embryos based purely on looks: those that had the best organization and highest number of cells would be transferred. But with RMA’s advent of CCS, doctors could now see the exact chromosomal makeup of an embryo.
The test, now offered on a next generation sequencing platform, called NexCCS, allowed geneticists to see whether the embryo had the correct number of chromosomes, known as euploidy, or had a missing or extra chromosome, known as aneuploidy. Because abnormal, or aneuploid, embryos can fail to implant, lead to miscarriage or result in an affected baby, doctors are not advised to transfer them.
CCS was a monumental achievement because it allowed doctors to identify normal embryos for transfer. That breakthrough resulted in an increase in implantation and live birth rates, a decrease in clinical loss rates, a reduction in time in treatment and a reduction in overall patient cost.
Finally, RMA doctors and researchers helped the industry understand the benefits of a Frozen Embryo Transfer (FET) through their inquiry into uterine receptivity. It may sound hard to believe, but the uterus is highly-receptive to implantation by an embryo for 24 hours during each ovulation cycle, meaning that the embryo has to be inserted at just the right time to have a chance to implant. To preserve the embryo while doctors wait for a woman’s uterus to be receptive – as well as to give geneticists time to perform genetic testing on the embryo – it became necessary to cryopreserve, or flash freeze, embryos until the time was right to use them. This process became known as FET, which RMA’s research showed led to higher implantation rates than fresh embryo transfer.
Over time, these scientific discoveries formed clinical building blocks that have transformed the industry and led to a new standard of care that lessens risk, increases safety and translates to success.