News from Japan these week indicates that more than 1 in 30 births in that country in 2012 were the result of in vitro fertilization. That’s a lot.
During IVF, a woman’s eggs are harvested after a round or rounds of fertility treatment. These eggs are combined in a laboratory with her partner’s sperm and watched to see if fertilization occurs. The resulting embryos are monitored as they grow, and then some number of them are implanted back into the woman’s uterus in hopes they will implant there and create a successful pregnancy.
There is about a 30 percent chance that a cycle of IVF described above will result in a successful pregnancy. Because the chances are relatively low, women have two or more embryos transferred to their wombs. This causes a higher rate of twin and triplet delivery, and those ‘multiple pregnancies’ carry their own risks including high blood pressure and premature birth. Coupled with this is the fact that many women who chose IVF are of advanced maternal age, over 35, which presents other risks on its own.
It would be better and safer for mom’s using IVF if pregnancies could be limited to one baby. In order to achieve this, doctors are looking at ways to better screen embryos before implantation with the hopes of finding the one most likely to develop into a successful pregnancy.
Chromosomal screening looks at the genetic health of an embryo before its implanted. A 5-day-old embryo has about 120 cells. Doctors take just a few of these, which the embryo can replace, to ensure the right amount of genetic material is there. This process doesn’t check for specific genetic defects, but still costs up to $4,000.
A second technique uses cameras to take time lapse photos of the embryos growing and dividing. “The embryo’s fate can be determined very early in development,” says Barry Behr, director of Stanford University Medical Center’s IVF laboratory. Uneven cell division is often a sign that something is wrong with the blastocyte.
As these screening processes become mainstreamed into IVF, more women will have successful, singleton pregnancies, further reducing any complications that may develop from using fertility procedures to conceive. And as men and women continue to delay marriage and conception, IVF and other fertility methods are almost certain to become more common. It’s important that they be as safe as possible.
Meredith Knight is a blogger for Genetic Literacy Project and a freelance science and health writer in Austin, Texas. Follow her @meremereknight.