A large study finds that combining two fertility tests could increase the success rate of in vitro fertilization (IVF).
Researchers from the University of Oxford found that analyzing chromosomes for signs of problems as well as examining the mitochondrial DNA (mtDNA) can give couples a more accurate prognosis as to whether an IVF treatment will be successful.
Apart from being the main energy providers to the embryo, mitochondria also have other critical roles to play.
Past studies found that some embryos possess high levels of mtDNA, which prevent it from developing into a baby. In recent years, experts have been studying the mitochondria's crucial role in enabling women to produce healthy babies.
In the new test, the combination involves the routine chromosomal screening and then analyzing further why the remaining embryos do not develop into a baby.
The research team studied 280 embryos, which were grown in the laboratory for up to six days. They were deemed chromosomally normal. From the original batch, the researchers placed 111 embryos into women through IVF, and 78 of them (70 percent) resulted in ongoing pregnancies.
The researchers noted that all successful pregnancies involved embryos with normal levels of mtDNA. Out of the 33 failed IVF, eight of them (24 percent) had remarkably high levels of mtDNA.
"The results confirm that embryos with elevated levels of mitochondrial DNA rarely implant and support the use of mitochondrial quantification as a marker of embryo viability," said Dr. Epida Fragouli from the Reprogenetics UK as well as the Nuffield Department of Obstetrics and Gynaecology at the University of Oxford.
The findings were presented at the European Society of Human Reproduction and Embryology conference held in Helsinki this week. The findings can lead to combined tests that can boost IVF success results in the United Kingdom.
The same test is already being utilized in the United States. UK's Human Fertilisation and Embryology Authority is analyzing if the same test should be allowed within the UK.
"It is looking promising and I think that we would certainly like to discuss it with our patients as an option for them," said consultant gynecologist Stuart Lavery, who is the IVF Hammersmith director at the Hammersmith hospital in London.
According to the National Health Service, in 2010, the success rate of IVF treatments among women under 35 was 32.2 percent. For women aged 35 to 37, the success rate was 27.7 percent; for women aged 38 to 39, the success rate was 20.8 percent.
For women aged 40 to 42, the IVF success rate was only 13.6 percent; women aged 43 and 44 had a success rate of 5 percent. Lastly, women aged over 44 had only 1.9 percent success rate.
