Posts Tagged ‘PGS’

Day 5 embryo biopsy for PGD or PGS less harmful to embryo than Day 3

Monday, October 24th, 2011

A study presented at the American Society of Reproductive Medicine Conference in Orlando last week, aimed to compare the safety and efficacy of embryo biopsies conducted for the purposes of screening for genetic disease at day 3 (cleavage stage) versus day 5 (blastocyst stage) of embryonic development. The impact that biopsy has on an embryo's ability to implant and develop into a baby had never previously been studied.

For twenty years, embryo biopsy for genetic disease screening prior to IVF transfer had been conducted on day 3, known as the cleavage stage, when only 6-8 cells have formed.. Day 3 biopsy involves removing 1-2 cells for testing. and removal of such a proportionately large percentage of the embryo reduces the embryo's chances of implantation.

More sophisticated techniques now allow biopsy on day 5, the blastocyst stage, when 200 or more cells are present.  The reason that day 5 biopsy does no apparent harm is that a dramatically smaller portion of the embryo is removed. Another reason is that the sample is taken from the outer layer of the embryo destined to form the placenta, called the trophectoderm (TE). The cells that form the baby are undisturbed, preserving the embryo's true potential.

Another advantage to the Day 5 biopsy is that a number of cells can be evaluated, reducing the chance for an error when one cell of an eight cell embryo may not reflect the remainder of the cells in an embryo, a phenomenon called mosaicism.

At Reproductive Partners we have been performing Day 5 biopsies for some time and find that it is a real advantage over Day 3 biopsies,

Reproductive Partners website is now in Chinese

Monday, May 9th, 2011

Reproductive Partners Medical Group, Inc. is pleased to announce that our website is available in Mandarin Chinese. Look for the box on the Home Page to link to the Chinese version.

There has been a lot of interest in IVF technology in China. Our doctors Rosen and Yee have been invited to lecture later this month in Beijing on the latest IVF technology. They will be concentrating on new PGS technology as well as improved cryopreservation techniques using vitrification. They will also be addressing preconception examination of an individual's genome for resessive genetic diseases.

Question on Comparative Genomic Hybridization (CGH) for PGS

Thursday, September 30th, 2010

An interesting question on the Reproductive Partners Fertility Forum about possiblility of doing preimpantation geneic screening for chromosomes (PGS) on frozen blastocysts raises some important points.

Q. I currently have frozen embryo's in La Jolla, we have a 17 month old son and are now starting to discuss a second child. My question is if CGH can be perfomed on frozen 5 day embryos or do they need to be fresh for this procedure? I also understand that it is best if they were frozen via vitrification, but can it still be done if the embryos were not frozen in this manner? Finally is this procedure offered through RPMG?

A. Technically, CGH can be done on trophectoderm biopsies on frozen blastocysts. We have done it.

The problem is that by the time you get results the embryos are beyond the normal time for transfer; not 5 day embryos, but now 7 day embryos and there are no studies I am aware of showing consistent success transferring that late. They could be refrozen, but that would probably seriously impair the embryos.

So this is something that has to be worked out better before I would recommend it for frozen embryos. We will be recommending it in appropriate cases in fresh cycles, then freezing the embryos by vitrification and doing frozen transfers.

Comment: The most recent evidence shows that PGS done on Day 3 embryos using the florescence-in-situ-hybridization (FISH) technique has not been shown to improve live birth rates
in the patients for whom it's been traditionally recommended. Thus the American Society for Reproductive Medicine has deemed it generally not recommended for maternal age, repeated miscarriage or other common indications.

The new technique of biopsying the surrounding cells of a blastocyst and checking all chromosomes, then freezing the embryo by the newer technique of vitrification, and transferring in a frozen embryo cycle should overcome most of the pitfalls of the older technique. Unfortunately there is not enough experience with already frozen blastocysts at this time to recommend it to the person who posed the question,

RPMG moves to CGH for PGS for chromosomes

Tuesday, April 27th, 2010

RPMG will now be using comparative genomic hybridization (CGH) for preimplantation genetic screening (PGS) for chromosome screening of embryos (including for sex selection). CGH is a technique that involves amplifying the DNA and uses many thousands of probes to check all 23 chromosome pairs. As long as an intact nucleus is biopsied, it is virtually error-free, whereas with the older technique, fluorescence in-situ hybridization (FISH), many errors may occur because FISH relies on binding of a single probe to each chromosome, and there are potential cell fixation artifacts, overlapping signals, and a subjective microscopic analysis is required. It also does not analyze all chromosomes. Unfortunately many normal embryos have been discarded with that technique due to these artifacts, and false negative results have also occurred where an embryo appeared normal but was actually abnormal.

For more information on PGS for chromosomes please check our our PGS for chromsomes page.

Does preimplantation genetic screening (PGS) improve IVF success rates in women over 35?

Friday, March 5th, 2010

Some fertility centers promote preimplantation genetic screening as a way of improving IVF success rates in women over 35 (defining advanced maternal age).

Now a study in the January 2010 edition of Fertility & Sterility shows that PGS does not significantly improve implantation, pregnancy or live birth rates. In this randomized control study from Belgium, the clinical implantation rate per embryo transferred was compared between the PGS group (analysis of chromosomes 13, 16, 18, 21, 22, X, and Y by FISH) and the control group without PGS.

No differences were observed between the PGS group and the control group for the clinical implantation rate, the ongoing pregnancy rate at 12 weeks and the live born rate per embryo transferred.  A normal chromosome component was observed in only 30.3% of the embryos screened by PGS.

In this randomized controlled trial, the results did not confirm the hypothesis that PGS by FISH in 3-Day embryos results in improved reproductive outcome in patients with "advanced maternal age.".

In the future newer techniques of chromosome analysis such as comparative genomic hybridization (CGH) which can analyze all chromosome pairs and the ability to analyze blastocyst cells, freeze the embryos and transfer only chromosomally normal embryos may result in better outcomes and the need to transfer fewer embryos and reduce high-order multiple pregnancies as well.

Girl Crazy: Women Who Suffer from Gender Disappointment

Tuesday, October 20th, 2009

IMG

Reproductive Partners was cited in an article in the November 2009 issue of ELLE magazine, “Girl Crazy: Women Who Suffer from Gender Disappointment.” The article profiles women whose lives are disrupted because they have not been able to have the girl child that they are craving. According to the author, they resort to a variety of techniques to try to achieve their elusive dream from folk remedies to IVF with preimplantation genetic screening (PGS), also know as preimplantation genetic diagnosis (PDG) for chromosomes. The focus of the article was the degree of emotional impairment from which these women suffer rather than the procedure itself. The article profiles a physician whose practice is devoted to IVF/PGS for gender selection, although the technique is widely available, including at Reproductive Partners.

The article states, “Physicians at other clinics, including California’s topranked Reproductive Partners Medical Group, use PGD as a screening tool to identify embryos with defects, and—if pressed— will reveal the sex of embryos in conjunction with other findings. ‘We would transfer embryos of one sex or another if that is the patient’s preference,’ says Arthur Wisot, its executive director and a clinical professor of reproductive medicine at UCLA. ‘We would do it if they seem like reasonable people and no one is hurt by it. But we certainly don’t advertise it and promote it the way Steinberg does. The people he services are more on the fringe, and he’s just playing to their neuroses.’”

 Actually Reproductive Partners offers IVF/PGS for family balancing and we do not need to be “pressed” to reveal the sex of embryos. It is just not the only focus of our practice. We mostly employ this technology to detect embryos with chromosomal abnormalities, when appropriate, and diseases caused by known gene abnormalities carried by one or both parents. In fact, the most recent recommendation from the American Society for Reproductive Medicine has reduced the number of reasons for doing PGS for chromosomes because of evidence that it does not improve live birth rates in patients with advanced maternal age, previous implantation failure, recurrent pregnancy loss and even those who have recurrent pregnancy loss from chromosomal abnormalities.