Risk of sperm contamination without ICSI

[bows&ribbons]

Hi!
I am not comfortable with ICSI if we don't need to use it and one lab we are considering requires it while another dr. doesn't. The dr that requires it stated that there is a risk of contamination from other sperm that will render the evaulation of the embryo in terms of gender and other anomalies inaccurate. What do you think of this? Many pgd labs dont require icsi. Also is there a way that an embryologist can determine whether an embryo has been contaminated by sperm other than the one that fertilized it? Is there a way for the embryologist to biopsy a portion that is clean and uncontaminated?
Thanks so much again!

[lovehugs]

I think it has something to do with two sperm being able to penetrate the egg if you don't use ICSI. If this happens then depending on which cell they take to test they could take a cell from the sperm that doesn't actually fertilise the egg and hence get an incorrect result from the PGD testing.

Why don't you want to use it?

Just about 100% all of my eggs have fertilised well with ICSI in both of my cycles. If the eggs were left in a dish with the sperm I don't know what the fertilisation percentage would have been?

[Carole]

Dear All,
In my experience as an IVF lab director, ICSI was only required for PGD when the genetic test ordered required that the biopsied cell be liquefied and DNA from the liquefied sample is then amplified into millions of identical copies and analyzed. Contamination of even one molecule of "foreign" DNA can be amplified and can affect the results. In conventional fertilization, one sperm may enter and fertilize the egg, but hundreds of sperm may be attached to the outside of the egg or lying within the space between the egg and the zona. Any of these sperm may contribute their DNA to the test cell sample if that sample is removed with adherent sperm and liquefied.

On the other hand---If the test involves FISH, fluorescent in situ hybridization, the nucleus of the cell is prepped on a slide and whole chromosomes are detected with a labeled probe--no liquefaction and no amplification of DNA occurs in this test-- making stray molecules of DNA a non-issue. So it is the test, not the testing lab, that determines whether ICSI is necessary.

The embryologist can't really tell if a stray sperm has contaminated the sample or not. The best way to avoid contamination of a stray sperm is to expose the egg to only one sperm by doing ICSI.

Finally, ICSI, although becoming widespread due to fear of fertilization failure among clinics--it is still controversial because the long term effects are not entirely know. ICSI was first used clinically in 1993 so the oldest ICSI kids are only teenagers. I wrote a post on this topic which goes into greater detail about pros and cons of ICSI. http://fertilitylabinsider.com/2010/06/sperm-injection-the-good-the-bad-and-the-ugly/

The American Association of Bioanalysts is actually debating the topic of whether ICSI is overused at their annual conference: Here's the info: Debate: Should ICSI be Used for 100% of Cycles?

How much ICSI is enough? Can ICSI be over-used? The percentage of IVF cases that use ICSI in the US has shown a steady increase every year and appears to be headed towards 100% ICSI. The pros and cons of 100% ICSI use will be debated by two experts in the field at the 2011 AAB Conference/CRB Symposium, May 12-14, 2011, in Austin, Texas. Hear the "pros" from Levent Keskintepe, Ph.D., HCLD(ABB), SIRM, Las Vegas, Nevada, and the "cons" from Marius Meintjes, Ph.D., HCLD/ELD/TS(ABB), Frisco Institute for Reproductive Medicine, Frisco, Texas.

Some IVF centers have decided against using ICSI for all cases because there are still concerns about long term safety and outcome data is still being collected. Hope this helps, Carole.

[bows&ribbons]

When I spoke to the dr. at RMA, he indicated that in line with what you said, ICSI wouldn't be required for the day 3 biopsy using FISH technology. For a day 5 biopsy using PCR testing of all 24 chromosomes, it would bec any extraneous DNA can contaminate the results. At NYU, however, they use acgh and the dr. said tha ICSI wouldn't be required even for a day 5 biopsy. Do you think ICSI is required for acgh? SO i am leaning towards NYU, but the issue at NYU is that they require a FET for a day 5 biopsy. I'd rather fresh. Has their been any negative data on the health of the children born from FET?
Thanks again for all of your help!!!!!!!

[Carole]

Hi bows&ribbons,
I am not a genetics expert so I tried to find the answer about whether ICSI is always necessary for aCGH on-line ---with mixed results. I found a Reprogenetics handout on-line that says they don't require ICSI with aCGH, so obviously it is not always necessary as your doctor mentioned. Most of the time though, it looks like most clinics will do IVF/ICSI and not conventional IVF, to generate embryos before biopsy for aCGH. I don't understand the aCGH test well enough to know why it's not necessary when the whole genome's DNA is being amplified for aCGH but it is necessary for PCR. Maybe there are some genetic testing experts out there who could weigh in?

I did find that aCGH can be used to test the polar body of the unfertilized egg so sperm DNA contamination obviously isn't an issue when used for testing polar body samples.

If NYU has good pregnancy rates with FETs--meaning their FET rates are very similar to their fresh rates, there may be some advantages to having an FET, rather than a fresh replacement. In an FET cycle, you'll have some minimal hormonal stimulation to optimize the uterine lining for implantation. There is evidence that the high doses needed to stimulate your ovaries in a fresh cycle may result in sub-optimal priming of the uterine lining for implantation and some studies report higher preg rates in an FET cycle following a fresh PGD cycle than in fresh cycles following a day 3. The lower preg rate following day 3 biopsy may also be due to the greater sensitivity of the embryo to losing 1-2 of its cells as a cleavage stage embryo (with only 8-10 cells) rather than a smaller percentage (2-10 cells out of 100 cells) at the blastocyst stage. I am not aware about any negative health effects on children born from FETs. Best Wishes, Carole