The most effective way to increase the odds that an embryo will successfully implant during in vitro fertilization (IVF) is genetic testing to see if the embryo is normal.
But the news often isn’t good. By the time a woman is 44 years old, the vast majority of her embryos will be abnormal.
A new study asked women who had their embryos tested before IVF if they were glad or regretted the procedure?
Regardless of whether they had a normal embryo or not, 94 percent of patients surveyed were glad to have the information, a new study from Northwestern Medicine and New York University Langone Fertility Center reports.
This is the first study examining the risk of regret and anxiety following screening for chromosomal abnormalities in embryos before IVF.
The paper will be published June 21 in Human Reproduction, a journal of the European Society of Human Reproduction and Embryology.
“The traditional practice of IVF involves transferring an embryo, with an unknown likelihood of implantation, and finding out on the other end whether it will implant or result in a healthy pregnancy,” said lead study author Dr. Kara Goldman.
“We discovered that even after a negative outcome, most women found the information gained from embryo testing to be valuable for reproductive planning.”
Goldman is an assistant professor of obstetrics and gynecology in reproductive endocrinology and infertility at Northwestern University Feinberg School of Medicine. She also is the Northwestern Medicine director of fertility preservation.
“Older women understand their time is limited,” Goldman said.
“If they lose three months because of a miscarriage, that’s a lot of time.
Most patients like the idea of having as much information in front of them as possible, so they don’t have to go through the very difficult waiting period between the embryo transfer and the pregnancy test if the embryo wouldn’t have resulted in pregnancy.”
In genetic testing, clinicians check to see if there are too many or two few chromosomes, which will result in a miscarriage, an embryo that won’t implant or a chromosomally abnormal fetus.
The latter requires the parents to decide if they want to terminate the pregnancy.
A small but significant number of patients who had abnormal results, or did not get pregnant with one of their normal embryos, did feel regret after the testing procedure.
“This study identified where we need to better help patients in terms of mental health services,” Goldman said. “We need to make sure we have our psychologists and doctors supporting patients when they have abnormal embryos and are preparing to make their subsequent treatment decisions.
“The most common reason for patients to drop out of IVF treatment before they are successful is the psychological burden,” Goldman said.
“Genetic testing of embryos is an area where we have thousands of patients using this technology and no one has studied the psychological burden of it.”
IVF is used widely among patients with infertility, and in the United States nearly 2 percent of all babies born were conceived with IVF.
The study was conducted via an anonymous internet-based survey completed by 69 patients between January 2014 and March 2015 after screening for chromosomal abnormalities.
The patients were from New York University Langone Fertility Center, where Goldman was on faculty prior to joining Northwestern. The survey included three validated questionnaires including the Brehaut Decision Regret Scale, short-form State-Trait anxiety inventory and health literacy scale.
The title of the paper is “Beyond the biopsy: predictors of decision regret and anxiety following preimplantation genetic testing for aneuploidy” by Kara N. Goldman et al.
What is PGS?
PGS (also known as aneuploidy screening) involves checking the chromosomes of embryos created by in vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI)for abnormalities.
Embryos with abnormal chromosomes often end in miscarriage, a failed treatment cycle or the child may have a condition like Down’s Syndrome.
During PGS, a single cell or a small number of cells is removed from the embryo.
The DNA of these cells is then tested to see whether they have any chromosomal abnormalities. Only embryos without chromosomal abnormalities are placed back in the womb.
Who might be recommended to have PGS?
Older women are more likely to have eggs with the wrong number of chromosomes, so traditionally it’s been offered to women over 37.
Abnormal chromosomes are thought to be the main reason why older women have difficulties conceiving and are more likely to have a miscarriage or a baby with Down’s Syndrome.
Your doctor may also recommend PGS if you have a family history of chromosome problems, if your sperm is at risk of carrying abnormal chromosomes, or if you’ve had several miscarriages or failed IVF attempts without explanation.
However, there is limited evidence to show that PGS benefits these groups (see more below.)
What causes abnormal chromosomes?
Abnormal chromosomes happen very frequently during the normal production of eggs, sperm and during embryo development.
When the cells of eggs, sperm and embryos divide this can lead to too many or too few chromosomes, or with missing or added pieces of DNA.
Does PGS work?
In the past, some clinics recommended PGS to older women with a history of miscarriage or failed IVF cycles, men whose sperm was at risk of having chromosomal abnormalities or people with a family history of chromosome problems. However, to date there is little evidence showing it improves success rates for these groups.
There have been some small clinical trials which have shown that PGS can improve IVF success rates for women under 37 with no history of miscarriage or failed IVF cycles.
Until larger trials have been run and we have more evidence, there’s no guarantee that PGS can improve your chances of pregnancy.
How safe is it for the embryos?
Because PGS involves removing a cell or number of cells from an embryo this can cause damage to the embryo and prevent it from developing once it has been transferred into the womb.
Also research has shown that often the cells in an embryo are not chromosomally identical (called mosaicism).
PGS relies on test results from one or a small number of cells being representative of the embryo as a whole.
As this is not always the case, it may be possible for an embryo to give an abnormal test result when it is in fact capable of producing a healthy pregnancy.
Journal information: Human Reproduction
Provided by Northwestern University
