For women and couples struggling to conceive a child, in vitro fertilization (IVF) has long been an alternative to natural conception. IVF was first successfully used in 1978 and now more than five million babies have been born this way. The technique helps women who can’t conceive naturally by fertilizing an egg with sperm outside of the body. Embryos are created this way and then implanted in the woman’s uterus. Although there have been millions of success stories with IVF, there have been many more failures. Now, a new technique for screening the chromosomes of the embryos may help drastically improve success rates for IVF procedures.
IVF is Imperfect
Success rates are not very high for IVF, although it has worked for millions of women and couples. The success rate is only about 33 percent for women under the age of 35 and it decreases with age. By 40, a woman only has a 12.5 percent chance of having a viable pregnancy from IVF. The reason that so many embryos created by IVF fail to result in a pregnancy is related to chromosomal abnormalities. Doctors have so far had no way of knowing for certain which embryos will be successful and which will fail. To counteract this uncertainty, most women getting IVF treatments have several embryos implanted together in the hopes that at least one will lead to a viable pregnancy. This is why IVF sometimes results in multiple births, even as high as octuplets.
Next Generation Sequencing
The answer to the problem of low IVF success rates is next generation sequencing. The term refers to a collection of the most modern techniques for investigating DNA and chromosomes. They are considered high-throughput, which means they can be done quickly and less expensively than ever before. With these techniques, testing the chromosomes of embryos created by IVF is easier and more accessible than ever.
A few cells are taken from each embryo created for an IVF treatment and are tested using a modern, next generation sequencing technique. The test counts the number of chromosomes in the embryos’ cells. Those with too many or too few chromosomes are not likely to be viable. By using this type of testing a doctor can know for certain which embryo should be used for implantation for the greatest odds of achieving a successful pregnancy. It eliminates guess work and the need to implant multiple embryos.
The first baby to be born using next generation sequencing along with IVF came into the world in 2013. The test is now cheaper and more available than ever before and has opened up the door for improving success rates for IVF. Some experts believe that it will help IVF success rates approach those of natural conception. Time and more research will tell if the improvements are as great as expected.
For couples struggling with conception and relying on IVF to help them have a baby, the news about more widespread and affordable embryo testing is exciting. To be able to select for a viable embryo could help many more women have children, but it also raises ethical questions that must be answered in the future. Selecting for embryos that will actually lead to pregnancy is ethically sound, but the question is one of drawing a line. Should we select for disease-free embryos? For eye and hair color? For now, it is enough to know that modern next generation sequencing techniques make the possibility of pregnancy for millions of women more of a reality.