This summer, we are introducing a new procedure in our laboratory that will allow us to do genetic testing on embryos that have reached the blastocyst stage of development. Traditionally, embryos are biopsied when they are just 3 days old at which time they should have reached the 8-cell stage (see figure 1). The biopsied cell is sent to the genetics laboratory for testing while the remainder of the embryo continues to grow in our laboratory. The genetic testing results are received 48 hours later, when we hope that the embryo will have reached the blastocyst stage (see figure 2). Blastocysts that have passed genetic screening can be transferred or frozen for later use.

Performing the biopsy when the embryo has become a blastocyst is more technically challenging, and it allows less time for the genetics lab to do their testing. However, in a blastocyst, we are specifically able to biopsy from the part of the embryo that will become the placenta, and we can get more than 1 cell, which allows for greater accuracy in the genetic testing. Depending on how quickly the test is run, the embryo may have to be frozen while we wait for the results.

While freezing is inconvenient, it does allow time for more complex genetic testing, and for multiple tests if necessary. And, with the success of vitrification for preserving embryos (see Fertility Flash Vol. 7, Issue 3), we are confident that the frozen embryos will survive and implant at high rates when thawed.

In the next few years, we expect that the traditional methods for biopsy and genetic testing will disappear and that blastocyst biopsy will be the standard procedure. As genetic testing evolves, it will not be possible to rely on just a single cell from an embryo to get dependable results. We already know that there is genetic variability among cells in an individual embryo, a phenomenon known as mosaicism, and our new procedure will overcome this problem.

In the coming months, we will announce an exciting new partnership with a Bay Area genetic testing lab, and we will keep readers informed on our progress with genetic testing in embryos. This is an exciting field that continues to evolve.

Pacific Fertility Center is pleased to share our delivered pregnancy rates for 2007 and our preliminary clinical pregnancy rates for 2008. These outstanding pregnancy rates are made possible thanks to our team of board certified Reproductive Endocrinology and Infertility specialists, as well as, our highly trained embryologists.

Clinical pregnancy reflects the finding of a pregnancy sac in the uterus following transfer. Delivered pregnancy rate will be lower after accounting for miscarriage and pregnancy loss, particularly in older age groups.

Pacific Fertility Center Preliminary Clinical Pregnancy Rates for 2008

Delivered Pregnancy Rates 2007 (as reported to SART and CDC)

For many people, the dream of having a family also includes the dream of having children of both sex. Since most families today are much smaller than in generations past, the odds of having two or three or even four children of the same sex is fairly high.

Throughout human history, there always has been interest in methods to sway the chances of conceiving a child of a particular sex. Today, in the 21 st century, it is quite clear that many of these sometimes bizarre and sometimes simple home remedies have no basis in fact.

There are ways to significantly shift the odds of having a child of one sex or another. Sex is conferred on an embryo by whether an X-bearing sperm (for a girl) or a Y-bearing sperm (for a boy) enters the egg. Unfortunately, despite highly publicized claims, there are no proven effective “at home” methods of sperm separation. Nor does timing of intercourse relative to ovulation affect the 50:50 sex ratio. By natural methods, the ratio remains a flip of the coin.

The only commercially available method for sperm separation that appears to be effective is the sperm sorting process available through Microsort.net. This method involves using a fluorescent DNA dye that attaches to either X or Y chromosomes. The sperm then passes through a cell sorter that separates the sperm based on the fluorescence. This method is still under FDA investigation for safety and efficacy but does appear to do a reasonable job in separating sperm, especially if the desired sex is female.

Mirosort reports a 90% success rate with separating X-bearing sperm and a 73% success rate in separating Y-bearing sperm. There have been only a few hundred babies born thus far, but there does not appear to be any increase in birth defects. Because this process is still considered “experimental,” couples wishing to participate, will have to travel to either Fairfax, Virginia (Microsort headquarters) or an affiliated clinic in Southern California for fresh sperm insemination.

Unfortunately, after Microsort processing, the number of sperm available for insemination is severely decreased. Freezing and thawing of sperm, which would allow the sample to be shipped to another location, reduces these numbers even further. Because sperm counts are so low after sorting, it is usually necessary to do in vitro fertilization with sperm injection (IVF-ICSI) to significantly improve the fertilization in the IVF laboratory. PFC is a participating site in the FDA investigation for Microsort. We have used sperm specimens that had been previously Micro-sorted for IVF-ICSI.

Researchers at UC Irvine recently published a study describing the use of lasers to “trap” the heavier and slower moving X-bearing sperm to separate it from the lighter Y-bearing sperm. In the future, this process may provide an alternative to Microsort. However, it is not yet commercially available.

Beyond the Microsort technique, the only way to improve the odds of selecting one sex over another at close to 100% accuracy is to undergo Pre-Implantation Genetic Screening (PGS). PGS uses a DNA-binding technique to determine if there are a correct number of chromosomes in the embryo at the time of IVF. To complete this screening, embryos on Day 3 of culture (5-10 cells) undergo a biopsy to remove a single cell. The rest of the embryo remains in culture in the IVF laboratory. The removed cells are analyzed for the correct number of chromosomes. Currently, PFC with its cytogenetic partner, Genetics and IVF Institue screen embryos for 3-12 chromosomes. This screening is called “aneuploidy screening.” We allow our patients to know and select the sex of their normal embryos for transfer if they so wish.

Although IVF with PGS is the most effective method for sex selection, it is certainly the most expensive and there is no absolute guarantee that the transfer of the screened embryos will result in pregnancy. A PFC physician can best discuss the odds of success, based on the woman’s age and the couple’s history of childbirth.

Many couples undergoing PGS are doing so to screen for specific genetic defects or are specifically undergoing sex selection because of their risks of having a genetic disease that only affects males (X-linked diseases).

On the other hand, PGS for elective sex selection, either for “family balancing” or even for having a first child of a particular sex poses difficult ethical issues. Just because we have the ability to choose the sex of a child, should we? What will the couple do with normal embryos of the undesired sex? At PFC, we do not encourage PGS for elective sex selection. However, if a couple is undergoing IVF and wishes to undergo aneuploidy screening, we do allow them to select to transfer embryos by sex. We encourage all patients to consider donating excess embryos of the undesired sex for adoption by other couples.

Women or couples interested in this procedure should discuss it with their Reproductive Endocrinologist. At PFC, we also refer our PGS patients for a special genetic counseling session at California Pacific Medical Center in preparation for this process.

Question: I am an OB/GYN in the bay area and I have a patient that is interested in having a baby girl. She asked about “sperm spinning” as a method of gender selection and whether it would be useful in her situation.

Answer: Our office receives a lot of questions from patients and members of the public about sex selection. Our location in the very liberal San Francisco may be cause for the increasing demand we see in having a baby of a predetermined gender. People are also well informed about what can be achieved with modern technology, and since sex selection is a reality, there’s definite demand for it.

The procedure that you ask about, “sperm spinning” is better known in the medical and scientific communities as the “Ericsson Method”. The technology was developed by the German scientist Dr. Ronald Ericsson and has been licensed in the US and internationally since the early 1970′s. It takes advantage of the fact that sperm bearing a Y chromosome (that would make a boy) are very slightly lighter than X-chromosome bearing sperm (that would make a girl). The distribution of X and Y bearing sperm in a normal sperm sample is equal, but Ericsson’s method uses gentle centrifugation of sperm through a slightly viscous fluid to segregate the heavier (girl) sperm from the lighter (boy) sperm. Since the difference in the weight of the 2 types is so slight (about a 3% difference in amount of DNA), a perfect separation cannot be achieved. Ericsson’s website (www.childselect.com) claims a 78-85% success rate in couples seeking a boy and a 73-75% success rate for girls. At PFC, we do not endorse or recommend this method of sex selection, nor can we verify the above success rates. As far as we know, couples availing of sperm spinning are not given details of how well purified their samples are prior to using them for insemination.

A more reliable method for separating sperm in our opinion is the “Microsort” technique offered at the Genetics and IVF Institute (www.givf.com) in Fairfax, Virginia. The technique was developed originally by Dr. Lawrence Johnson at the US Department of Agriculture, and was later refined for use in humans in collaboration with GIVF. Microsort also takes advantage of the small difference in DNA content between “boy” and “girl” sperm. The sperm are dyed with a stain that binds to DNA and then an instrument called a flow cytometer can effectively separate populations of sperm based on how much dye they have incorporated. The Microsort scientists test a small aliquot of every separated sample to determine the exact enrichment that they have achieved. According to the latest figures posted on their website (microsort.net) the average enrichment for X-bearing sperm is 88% with 91% (525/574) of babies born being female. The technique is less effective for Y-bearing sperm with an average sample purity of 73% and 76% (127/152) of babies born being male. Bear in mind that the figures for babies born might be distorted since some patients may have terminated pregnancies that were not the gender that they were seeking. You may also have noticed from the GIVF data that there’s more demand for girls than boys. This is likely due at least in part to the fact that X separations work much better and therefore may be used more, but Dr. Ericsson’s website also claims a much stronger female demand even though his technology supposedly works better for boys. We do support the use of Microsort sperm here at PFC but there are limitations on the use of this technology. First, the sperm can only be separated in 2 laboratories in the US, (Fairfax and Huntington Beach in southern California), and the Microsort researchers prefer that you attend in person to give a fresh sperm sample. Second, the technology is currently only offered under an FDA approved clinical trial, and you have to be doing family balancing or trying to avoid a sex-linked disease in your family to be enrolled. For most people, unless you already have a child of a different gender from the one you are seeking, you won’t be able to participate in this FDA study.

Last, but not least is preimplantation genetic screening (PGS) that can be used to tell the sex of embryos created during in vitro fertilization (IVF). We feel that this technology is the most accurate of the sex determining strategies since there’s less than a 3% chance of a misdiagnosis. Embryos generated in an IVF cycle are subject to a biopsy procedure on the third day of growth that allows a single cell from the embryo to be analyzed to see if it has 2 X chromosomes (female) or X and a Y chromosome (male). IVF with PGS is the most accurate method for sex selection, but also the most involved and the most expensive. The Ericsson method is the easiest and the cheapest, but carries a greater risk of being inaccurate.

Joe Conaghan, PhD

The American Society for Reproductive Medicine’s (ASRM) annual meeting was held in New Orleans. It is the largest meeting for reproductive medicine specialists and scientists in the world. From our practice, Dr.s Givens, Schriock and Conaghan attended, as well as embryologists Jean Popwell, PhD and Jennifer Andres. Also, PFC nurse Allison Chamberlaine and PFC’s Marriage and Family Therapist Peggy Orlin attended. In addition, the genetics counselor with whom we work closely, Lauri Black from California Pacific Medical Center, was an attendee and active participant.

PFC’s embryologists attending ASRM’s research poster session Jean Popwell, PhD (left) and Jennifer Andres (right).

Single-Embryo Transfer: Minimizing Risks & Maximizing Outcomes
Dr. Givens attended a post-graduate course entitled “Moving Toward Single-Embryo Transfer: Minimizing Risks and Maximizing Outcomes.” This two-day course dealt with a pressing issue in assisted reproduction: the high incidence of multiple gestations. With the ever-increasing success of in vitro fertilization and the significant improvement in embryo implantation rates, the incidence of twin and higher-order pregnancies has risen dramatically in this country. Many countries now regulate the maximum number of embryos that can be transferred into the uterus at one time. The course topics included a summary of optimal medication protocols, several lectures on pre-cycle evaluation and testing and embryo transfer techniques.

Oocyte Freezing, PGS & Blastocyst Embryo Transfers
On the laboratory side, there were several talks on evaluation of eggs and embryo selection techniques, embryo freezing technology, including a debate about the usefulness of pre-implantation genetic screening (chromosome analysis of embryos) embryo selection. The combination was a fascinating mixture of new ideas, refinements in current technology, as well as a welcome opportunity to network and discuss with others the latest developments in reproductive science. Topping the list of presentations in New Orleans were those concerning the continuing refinements in oocyte freezing technologies, the more selective use of preimplantation genetic testing and the ongoing scrutiny of blastocyst stage embryo transfers.

Slow-freeze vs. Vitrification
The traditional slow-freeze technology used so successfully with embryos for many years, has essentially stalled with oocyte freezing. It appears the slow-freeze technology has finally met its successor: a process called vitrification. Slow freezing has had very limited success with oocytes due to their large size, high water content and their extreme sensitivity to cryoprotective chemicals and to changes in temperature and pH.

Vitrification, a technology that cools cells so rapidly that ice does not form, has been such a success for oocyte freezing that many labs are now abandoning slow freezing altogether. Here at PFC, we have been developing protocols for oocyte vitrification throughout 2006 and are actively working on blastocyst vitrification. It was reaffirming to see that this technology has gained wide acceptance, and is showing excellent results.

Preimplantation Genetic Screening (PGS)
While vitrification is on the rise, it was interesting to see that another technology, Preimplantation Genetic Screening (PGS), was lacking in new improvements or viable alternatives. Embryos have been screened for extra or missing chromosomes for over 15 years now, but the technology has not advanced significantly over that time. It is still possible to count only 12 chromosomes in an embryo. Although the error rate per chromosome is very low, the accumulated error rate becomes significant as we count more chromosomes. PGS was “under the microscope” in several presentations in New Orleans and it appears PFC’s limited use of genetic screening is well justified. Specifically, PGS does not improve embryo selection and pregnancy rates in younger patients. Its use is limited in older patients because there are often too few embryos available to justify testing. The patients who benefit most from PGS are the younger patients who experience recurrent miscarriages. However, unless there is evidence that previous pregnancies were genetically abnormal, PGS may provide limited benefit to this group.

Blastocyst stage embryo transfers
While younger patients (those under 35) don’t benefit from PGS, they are the patient population most likely to benefit from blastocyst transfers. Culturing embryos for 5 days to the blastocyst stage, instead of the more traditional day 3 embryo transfer, is one of the main ways in which the laboratory staff can help in selecting the “best” embryo for single embryo transfer (SET) patients. Blastocyst culture techniques are well refined now and support the commitment within the community to transfer fewer embryos at one time. Furthermore, the promise of vitrification can reassure patients that their remaining embryos can be stored indefinitely when preserved at the blastocyst stage. Several presentations showed that blastocysts which were vitrified early, before their cavity (or cyst) had expanded too much, benefited most from the technology. In more advanced blastocysts, artificial reduction of the cavity gave superior results. It may not be long before vitrification is the procedure of choice for preserving all blastocysts.

2006 ASRM guidelines for numbers of embryos to transfer
The new 2006 ASRM guidelines for numbers of embryos to transfer were presented. See Tables 1 and 2 below.

The topic of whether or not federal or state legislation should regulate the maximum number of embryos to transfer was also discussed. Many people in the general public support such legislation but those of us in the field (and most patients) are opposed to the government regulating medical practice and arbitrarily setting limits on embryo transfer. In order to forestall such legislation, it is obvious that we must decrease the number of twin gestations (the number of triplet and higher-order gestations has already dramatically decreased in the last 5-7 years). At Pacific Fertility Center we have instituted a new emphasis on single embryo transfers and expect to significantly reduce the risk of multiples and achieve our goal of “optimal” pregnancy outcomes. (See From Us to You in this issue for a discussion of our 2006 statistics and please see Conception Health in this issue for a discussion of why it is important to try to achieve single baby conceptions.

– Carolyn Givens, MD and Joe Conaghan, PhD

Here are some images from the different techniques that can be used for gender selection

To read more about this process, see our Ask The Experts post

Pacific Fertility Center Team
Left to Right: Front: Philip Chenette, MD, Isabelle Ryan, MD, Carolyn Givens, MD
Back: Joe Conaghan, PhD, Carl Herbert, MD, Eldon Schriock, MD

Question: My husband and I have two boys and want to have a girl.
What are our options?

Answer: Gender selection is a complicated and difficult issue. Ethics aside, there really are only two proven methods. The first is a technique of sorting sperm cells called Microsort. If there is a healthy number of motile sperm present (no significant male infertility), the husband can fly to Southern California to the Microsort lab and have the sperm sorted. That sperm can then be used to inseminate the wife at Huntington Reproductive Center in Laguna Hills or can be frozen and shipped back to PFC for use in IVF. Because the technique results in such poor recovery of sperm, insemination may take several tries. This is why most of our patients will use the sperm in conjunction with IVF, in which case we can inseminate by single sperm injection (ICSI) several of the wife’s eggs, producing and then transferring embryos back to the uterus, and giving the couple a better chance of success. The sperm sorting method is much more efficient if the gender desired is female (see Microsort Facts below). We receive a report from Microsort about the estimated percentage of sperm that are X-bearing (female) vs. Y-bearing (male). Usually, for a female, that is about 85% and most couples interested in a girl are comfortable with those odds. For a male, the odds are lower (about 73%) and therefore, if a boy is really desired, most couples look to PGS (Pre-Implantation Genetic Screening).

With PGS, the patients undergo IVF with ICSI to create the embryos, and when the resulting embryos have 5-8 cells, a single cell is removed and analyzed for a number of chromosomes, including X and Y. If the couple wishes to transfer only the embryos of one gender, they will have to decide what to do with the remaining embryos. The technique is close to 93% accurate, which is a huge advantage over Microsort if male gender is desired. However, our most recent statistics with PGS indicate implantation rates tend to be lower. We do suspect that the procedure of removing a cell from the embryo may be decreasing the chances of successful implantation.

There are many more complex issues involved with PGS so we require our patients considering this process to meet with a genetics counselor (we work with the Perinatal Genetics program at California Pacific Medical Center for this counseling) to discuss the implications of undergoing this process in more depth.

– Carolyn Givens, M.D.

Microsort Facts • Sperm sorting technique

Two locations: Virginia and Southern California

Must be younger than 40 years old (or using egg donor)

Must be for Family Balancing (not first child)

Low % of sperm recovered

Efficiency for a girl is about 85%

Efficiency for a boy is about 73%

For more info, visit the website: www.microsort.net

You may have heard about Preimplantation Genetic Screening as a technique provided in the IVF laboratory, and may have wondered if this technology is one you should consider incorporating in your IVF cycle. When considering various technologies in your IVF cycle, it is always important to clearly define what information you wish to gather with this technology, and also understand the pitfalls of the technology.

We have two methods of screening embryos. The first is called Preimplantation Genetic Diagnosis, for couples that have a known and defined genetic disease (e.g. Cystic fibrosis, Huntington’s disease, thalassemia), or are carriers of a single chromosome abnormality (chromosomal translocation). In this case we screen the embryo(s) for that particular genetic disorder, and transfer appropriate embryos. For this type of genetic screening, the aim is to conceive a healthy, unaffected child.

The other type of genetic screening is called Preimplantation Genetic Screening, where we screen the embryos for abnormalities in chromosome number. We all have 23 pairs of chromosomes. Embryos that have extra or missing chromosome(s) (aneuploid embryos) are much more likely to not implant, or to produce a miscarriage. The incidence of implantation failure, or of miscarriage, depends on which chromosome(s) are missing or duplicated. We therefore can screen an embryo with a “five or nine chromosome panel.” At PFC we utilize the nine chromosome panel. We look at the nine chromosomes that have been identified as most commonly being associated with implantation failures or miscarriages to see if that particular embryo has the correct number of those nine chromosomes. If so, this embryo is deemed “normal”, and can be transferred back to the uterus.

So who might consider PGS? Patients who have had a number of failed IVF cycles (documented failed implantations), those with a poor response to ovarian stimulation or those with poor embryo development (poor responders), those with recurrent miscarriages (>2 first-trimester miscarriages), those with a prior aneuploid pregnancy, those who are at least 35 years old are all candidates for PGS. The chances of improved pregnancy rates with PGS are dependent on the indication for PGS.

When we started doing PGS for various indications, we expected a dramatic improvement in implantation rates, and therefore pregnancy rates, as we were transferring pre-selected embryos. As it turns out, we have not necessarily seen those expected improvements in all patient groups. Patients who are younger than 35 yeas of age have a better chance at improved implantation and pregnancy rates using PGS. Improvements can still be obtained for older patients, if the 9 chromosome probe set is used (some centers use a 5 chromosome panel). Studies now indicate that patients who have at least 6 fertilized eggs to screen will also have a better prognosis than those with 5 or fewer. For those patients who have five or fewer fertilized eggs in their IVF cycle, we may actually recommend not proceeding with the PGS. In this case less manipulation of embryos may provide the patient with the best overall chance at pregnancy. Patients who have had less than 3 failed IVF cycles may have greater benefit from PGS than those with > 3 failed cycles. Patients with a prior aneuploid pregnancy or with recurrent pregnancy losses can also expect an improvement.

For patients who have had repetitive IVF cycle failures, or repetitive pregnancy losses, a PGS cycle may be diagnostic (explain if those failures/losses are from a high number of abnormal embryos), and in that sense may provide important information that explains those fertility failures. With those answers, the patient can then decide about pursuing similar treatment cycles, or choosing other options (using a donor egg, pursuing adoption, or choosing to live child-free). Studies indicate that results from one PGS cycle are indeed predictive of probable results in subsequent PGS cycles. In other words, if we have a cycle with a higher than expected percentage of abnormal embryos, we have to anticipate that we will probably have a similar result in subsequent PGS cycles.

There are many proposed reasons to explain why we are not achieving a higher implantation/ pregnancy rate in PGS cycles. There clearly is added stress placed on the embryo(s) when one cell is biopsied out, and when the embryo is kept in culture for an extra day or two while waiting for the results of the genetic testing. We currently can only test for 9 chromosomes, and it is possible that there may be undiagnosed abnormalities on one of the untested chromosome pairs. There is also a small possibility that an embryo we deem “normal” may actually not be normal (false negative result). It also may be that simply looking at chromosomes is not the final answer. Most likely the integrity and health of the cytoplasmic structures, and other important structures of the egg are also critical in the ability of the embryo to develop into a viable and healthy pregnancy.

Who Benefits Most?

• Patients with < 3 failed cycles, and > 5 fertilized eggs
• Patients 35 year and older (if using a 9 chromosome panel)
• Patients with a history of recurrent pregnancy losses
• Patients with a previous aneuploid pregnancy
• Patients using PGS as a Diagnostic Tool for:
  - Repeated IVF failure
  - Non-obstructive Azospermia

So, while PGS is a wonderful tool that can be incorporated into the various techniques of your IVF cycle, you need to be aware of the strengths and limitations of PGS testing. Your physician can help guide you in terms of the appropriate use of PGS and whether you may benefit from incorporating PGS in your IVF cycle.

A recent development in the laboratory at PFC is the acquisition of a laser for use in key procedures. The laser will be used to assist in the processes of Assisted Hatching (AH), Intracytoplasmic Sperm Injection (ICSI), and Pre-implantation Genetic Diagnosis/Screening (PGD/PGS).

All of these procedures require us to make a small opening in the outside shell of the egg called the Zona Pellucida (zona). Prior to laser technology this opening was made with an Acidified Solution, which would slowly dissolve away part of the zona until a small opening was achieved. Now with the laser, a beam of light creates a precise opening in the zona.

Laser use for PGD: The red “pilot light” marks target for the laser. The white circle marks a “safe zone”. The laser is usually fired 3 times for assisted hatching and 5 times for PGD embryo biopsy.

The zona pellucida is a non-living, but important part of the egg. It specifically allows only 1 sperm through to fertilize the egg, and then immediately hardens, preventing other sperm from getting in. After fertilization, the egg divides into 2 cells, and then these divide again into 4 cells. As the embryo continues through these rounds of cell division, the zona keeps all the cells together, since it encloses the embryo. After 5 or 6 days, the embryo has enough cells to begin forming a placenta and the embryo hatches from the zona and attempts to implant in the uterine lining.

Assisted hatching (AH) is a procedure that has been around for about 15 years and it is something that is often performed in the laboratory just prior to an embryo transfer procedure. It is a simple and precautionary procedure where we create a small hole in the zona just before transferring embryos to the uterus. Since the zona is not a living part of the embryo, making a hole does no harm, and in fact facilitates the embryo in hatching from the zona once it’s in the uterus. A normal embryo should be able to hatch all by itself, but in some patients we perform this procedure just to make sure a problem doesn’t arise when the embryo tries to escape from its shell. For AH, the laser will allow us to refine the procedure considerably. Firstly, we will be able to make a hole of an exact size, and secondly, the procedure will be performed more quickly and we will therefore further reduce the amount of time that an embryo is being handled. Traditionally, AH takes about 5 minutes per embryo, but with the laser this time will be reduced to less than a minute. For the process of embryo biopsy for PGD/PGS, an extremely precise opening is made in the zona to facilitate the removal of one cell. Again, the laser will speed the procedure up considerably and reduce the time that we’re working on each embryo.

By now you might be wondering if there are any harmful effects of using laser light on embryos. According to several studies and expert opinions, laser-assisted hatching is superior to chemical-assisted hatching as seen by improved development of “hatched” embryos to the blastocyst stage (the stage at which an embryo will implant in the lining of the uterus). Furthermore, laser-assisted biopsy of cells from embryos for PGD analysis does not appear to have a detrimental effect on the continued development of the embryos versus embryos not undergoing any biopsy procedures. This indicates that using a laser to do the biopsy procedure appears to be safe.

Current lasers have several built-in safety features. The laser system is equipped with a second non-laser beam of light, similar to a penlight, which allows the embryologist to observe where an opening of the zona would be created prior to firing the laser. Also, the temperature that the embryo is exposed to is controlled by the use of Isotherm rings. Isotherm rings help the embryologist prevent potential harmful thermal effects on cells adjacent to the zona due to heat from the laser beam. The rings indicate both the drill hole size and the safety region based on temperature. With this interactive feature, the user can predetermine the hole size and eliminate practically all risk of impacting cells within the embryo.

PFC’s new laser system has been tested for both accuracy and precision. In addition, the lab staff is undergoing training with Laser professionals on its use and maintenance. They will have unlimited practice time, ensuring the highest level of safety and technique when it comes time to use it on human embryos.

– Jean M. Popwell, PhD TS (AB, PFC Lab Embryologist)

Preimplantation genetic diagnosis (PGD) is a technique used to identify many inherited diseases. PGD uses DNA amplification to identify embryos with specific mutations of single genes, which may have been acquired from the mother, or father or both.

What PGD can do:
1. PGD can diagnose embryos at risk for some specific genetic diseases if the parent(s) are known to be carriers, and the molecular genetic basis of that disease is known.
2. PGD identification enables elimination of those embryos carrying the genetic mutation that causes the disease in question. It cannot repair those mutations.

What PGD cannot do:
1. PGD cannot guarantee that the baby will be free of all diseases or birth defects because the genetic basis for many defects is unknown. At this time, it is impractical or impossible to screen for most diseases, such as diabetes and cancer, or birth defects such as cleft lip and palate.
2. PGD cannot diagnose all diseases, even if the genetic basis is known, because some of the rarer diseases do not yet have available DNA probes.
3. PGD cannot determine traits, such as eye color, height, intellectual or athletic abilities.
4. PGD is not perfect, despite how sophisticated it is. Errors in diagnosis can occur, albeit at a very low rate. Confirmation of the correct diagnosis should be done by chorionic villus sampling (CVS) or amniocentesis, once the pregnancy is established.

The second type of genetic analysis is what we like to call Preimplantation Genetic Screening (PGS) to look for abnormalities in entire chromosomes missing or extra chromosomes or multiple complex abnormalities in chromosome numbers.

What PGS can do:
1. PGS can screen for abnormalities in 9 out of the 23 chromosome pairs. Currently it is not technically possible to screen for abnormalities in the other 14 chromosome pairs.
2. PGS can help to reduce the risks of miscarriage, commonly due to Monosomy X (one X chromosome) or Trisomy 16 (three of chromosome 16).
3. PGS can help to significantly decrease the risk of Down Syndrome (Trisomy 21) and Trisomy 18, as well as abnormalities in numbers of sex chromosomes (X and Y) (These are among the few abnormalities in fetuses that can survive to the time of amniocentesis and birth).
4. PGS can reduce the number of embryos one must transfer to find the embryos most likely to succeed.
5. PGS may help couples experiencing multiple IVF failures to determine if the failed implantations may be due to aneuploidy (chromosomal abnormalities).
6. PGS can determine the gender of the embryo.

What PGS cannot do:
1. PGS cannot screen for specific genetic diseases couples at risk need PGD.
2. PGS cannot guarantee that the baby will be free of all diseases or birth defects.
3. PGS is not perfect. The detection rate is between 90-93% for the chromosomes analyzed, which is why we still recommend CVS or amnio as a confirmation of PGS findings.