Squishiness of a Fertilized Egg can Determine IVF Success, Study Finds
The squishiness of a fertilized egg can help experts determine which egg is the best option for implantation in in vitro fertilization (IVF), a new study is claiming.
For this study, the researchers set out to examine if there were ways of increasing the success rate for single-egg IVF. Current IVF procedures that only involve implanting one egg have a failure rate of about 70 percent. To reduce this rate, doctors often implant two embryos, which can lead to twins if both embryos survive.
"A lot of twins are born because we don't know which embryos are viable or not, so we transfer several at one time," lead author Livia Yanez at Stanford University said in a statement. "This can increase the risk of neonatal mortality and cause complications for babies and the mothers."
Yanez added, "We wanted to develop a mechanical test that could ascertain embryo viability well enough that doctors could implant just one embryo and have a very good feeling that it would be viable."
In their research, the team examined how squishy mice eggs were one hour after fertilizing them. They then reexamined the eggs when they had reached the blastocyst stage. The researchers noted the eggs that had a certain "push back" appeared to have developed into healthier and more symmetrical looking embryos.
After implanting the embryos into female mice, the researchers found that the embryos that were the squishiest at the beginning were 50 percent more likely to survive to birth when compared to the embryos that were selected using traditional methods.
The team replicated the study with human embryos and found that 90 percent of the embryos that had the right amount of squishiness became viable blastocysts. The team plans to implant these types of embryos into human participants to see if they would survive.
"It is still surprising to think that simply squeezing an embryo the day it was fertilized can tell you if it will survive and ultimately become a baby," David Camarillo, an assistant professor of bioengineering at Stanford, commented.
The researchers could not determine why the level of squishiness would affect an embryo's survival rate.
The study was published in the journal, Nature Communications.