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Posts Tagged ‘PGD – Preimplantation Genetic Diagnosis’
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Wednesday, February 10th, 2010
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The PFC Staff, as a unified team, is guided by the highest ethical standards. We provide our patients with the best quality, individualized, compassionate fertility care.
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Pacific Fertility Center and The Fertility Flash would like to invite you to a special Valentine’s Day event.
Do You Love Your Genes? Tweetup/Meetup (a Valentine’s Day event)
Thursday February 11, 2010 at 5:30pm
Pacific Fertility Center’s Education Center
55 Francisco St., Suite 550
San Francisco, California 94133 Get Directions
Please join us for genes, love, award-winning wine, chocolate, and tasty, healthy appetizers!
To view the invitation, click here
This is an in-person and virtual event for all who would like to participate and learn about the leading edge of genetics and fertility. We will also be tweeting live during the event to communicate with and connect tweeters.
Genes are an important part of life, especially for those who are struggling to conceive a child. At this event we will celebrate these building blocks of life in all forms, whether they come from biological parents, birth parents, or donors.
We will also be joined by representatives from Counsyl and the Gene Security Network (GSN) to speak about their cutting edge genetic testing technologies.
For more details on our presenters see:
Pacific Fertility Center: http://pacificfertilitycenter.com
Counsyl: http://counsyl.com
GSN: http://genesecurity.net
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Please RSVP at rsvp@fertilitywire.com or on Facebook at http://bit.ly/bopZUZ
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insights founded by fertility doctors. Visit us: http://fertilitywire.com
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—Best regards from all of us at Pacific Fertility Center.
More On: Bay Area, Events, Genetic Testing, PGD - Preimplantation Genetic Diagnosis, PGS - Preimplantation Genetic Screening Posted in Conception Health, What's New @ PFC? | No Comments »
Monday, October 26th, 2009
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Dr. Eldon Schriock has been at the forefront of assisted reproductive technology since 1981. He was a member of the medical team that performed the first in-vitro fertilization treatment in Northern California.
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Microarray Preimplantation Diagnosis (MA-PGD) created much excitement and interest at three recent meetings attended by Dr. Schriock; Pacific Coast Reproductive Society, The Midwest Reproductive Symposium, and the IVF Comprehensive Update.
PGD is a technique used to diagnosis genetic disorders by performing a biopsy of the embryo on day 3 or 5. PGD can diagnose single gene or chromosomal defects. PFC has been doing embryo biopsy for over 10 years. During this time the major method of diagnosing chromosomal disorders has been fluorescent in situ hybridization, FISH. FISH uses a fluorescent color to label individual chromosomes. This technique lacks accuracy and is now seldom used to screen embryos for the presence of missing or extra chromosomes. (refer to Fertility Flash Vol. 5 Issue 2). This technique, however, is still valid for identifying the gender of the embryo. MA-PGD uses a new technology, Single Nucleotide Polymorphisms (SNPs). SNPs are single bases, the building blocks of DNA, which can be in a different sequence in different individuals. Six to ten million SNPs have been characterized. This is the technology used in DNA fingerprinting in criminal or forensic work. Compared to FISH, where only one color marker identifies the chromosome, SNPs havethousands of markers per chromosome.
FISH can only identify 8-12 of the 24 unique chromosomes; MA-PGD will identify all 24 chromosomes, similar to amniocentesis. Identifying both single gene defects and chromosome abnormalities from one embryo cell was not possible with the older techniques, but can be done with MA-PGD. MA-PGD will identify whether the abnormal chromosome came from the mother or father. If from the mother, it will determine if the error was in meiosis I or II, or mitosis. In other words, it can identify in which stage of early cell division the genetic error occurred. Using MA-PGD, it may be possible to determine which embryo produced the baby when more than one embryo is transferred. The most important advance, however, will be the accuracy of the result. New research using MA-PGD shows that FISH is inaccurate over 40% of the time. MA-PGD appears to be nearly 100% accurate in diagnosing abnormal embryos.
This new technology is also helping to answer scientific questions. 50 – 70% of embryos with one missing or extra chromosome still develop to a healthy-looking day 5 blastocyst. This helps explain why beautiful blastocysts do not always turn into healthy pregnancies. MA-PGD will also raise new questions: Only 55% of chromosomally normal embryos turn into successful pregnancies in 30-year-olds, only 25% in 40-year-olds. Why do these embryos with a normal number of chromosomes fail? There is more to the embryo than chromosomes and more research is needed to determine what factors allow an embryo to develop into a healthy baby. Current areas of investigation include RNA production (transcriptomics), protein production (proteomics), and metabolic by products (metabolomics).
We will continue to update readers on PFC’s experience with MA-PGD in future Fertility Flash issues.
More On: PGD - Preimplantation Genetic Diagnosis Posted in From Us To You | No Comments »
Monday, September 21st, 2009
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Joe Conaghan, PhD, HCLD is internationally recognized for his work with human embryos and brings nearly two decades of experience in human embryology to the Pacific Fertility Center.
More about Dr. Conaghan
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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.
More On: Bay Area, Blastocyst Transfer, PGD - Preimplantation Genetic Diagnosis, PGS - Preimplantation Genetic Screening Posted in What's New @ PFC? | No Comments »
Wednesday, August 12th, 2009
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The PFC Staff, as a unified team, is guided by the highest ethical standards. We provide our patients with the best quality, individualized, compassionate fertility care.
More about The PFC Staff
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Many populations of the world have specific genetic conditions that are prevalent within their ethnic group. Consequently, numerous medical organizations have recommended that genetic screening for these conditions should be offered when women are either planning for, or are currently pregnant. We are all carriers of genetic conditions: generally this is of little concern, as it is highly unlikely that we would have children with a partner who is a carrier for the same condition.
The genetic conditions listed in the table below are recessive. A recessive gene mutation is “carried” by someone who is unaffected by the disease, and thus unaware of their carrier status. Men and women have equal potential to be carriers for recessive conditions. Even if someone is a carrier, we would not expect to see a family history of the disease. If there is a family history, the likelihood of being a carrier of that condition is generally greater than in the general population. Being a carrier for a genetic condition typically has no impact on the carrier’s health and development. However, if a carrier has a child with another carrier of the same genetic disease, the chance that the child will be affected with the disease is 1 in 4 (25%).
If only one partner is a carrier, and the other tests negative, then the risk of an affected child is low, but not zero (a result of the limited ability to test for all defects that would make one a carrier; see table). These genetic screening tests are typically performed on a blood sample.
Below is a table listing the minimum number of tests for various ethnic groups recommended by the physicians at Pacific Fertility Center prior to starting assisted reproduction treatment. Additional genetic tests may be considered after a discussion with your physician.
If you know that both you and your partner are carriers of the same genetic defect, you may be able to have embryos created in an IVF cycle and tested for their status. Preimplantation genetic diagnosis (PGD) is a technology that allows embryos to be tested for specific disease causing mutations. PGD can identify unaffected embryos for transfer back to the uterus or freezing.
—Guest Contributor – Certified Genetic Counselor Lauri Black, M.S., C.G.C
| Ancestral Population |
Genetic Desease |
Carrier Frequency |
Detection Rate* |
| All |
cystic fibrosis |
Approximately 4% in people of European (and Ashkenazi Jewish) ancestry and less common in other populations |
Approximately 88% for Europeans, 94% for Ashkenazi Jewish ancestry, less accurate for others |
| Ashkenazi (Eastern European) Jewish ancestry |
cystic fibrosis, Tay Sachs, Canavan, familial dysautonomia |
Approximately 3% for Tay Sachs, 2% for Canavan and 3% for familial dysautonomia |
Approximately 94-99%, (depending on the condition tested) |
| African/African-American, Chinese, Southeast Asian, or Mediterranean ancestry |
Hemoglobinopathies, such as sickle cell anemia and thalassemia |
Approximately 10% of African-Americans are sickle cell carriers; 5-6% of Asians and 12% of some Mediterranean populations are thalassemia carriers. |
Variable depending on method, but very high (in the 90 percentiles) |
*See lab specific accuracies on test result
More On: Fertility Testing, IVF - In Vitro Fertilization, PGD - Preimplantation Genetic Diagnosis Posted in Science Pulse | No Comments »
Sunday, March 1st, 2009
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The PFC Staff, as a unified team, is guided by the highest ethical standards. We provide our patients with the best quality, individualized, compassionate fertility care.
More about The PFC Staff
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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
| Oocyte Donation |
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Fresh |
Frozen |
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Number of Cycles |
191 |
153 |
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Pregnancy Rate per transfer |
66% |
34% |
| IVF – Own Egg |
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Age |
<35 |
35-37 |
38-40 |
41-42 |
>42 |
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Number of Cycles |
180 |
166 |
174 |
119 |
58 |
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Pregnancy Rate per transfer |
51% |
46% |
42% |
31% |
15% |
| PGS/PGD – Own Egg, < 40 years of age |
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Number of Cycles |
32 |
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Clinical Pregnancy Rate per transfer |
56.3% |
| Elective Single Embryo Transfer (eSET) |
| Oocyte Donation |
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Number of Cycles |
73 |
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Clinical Pregnancy Rate per transfer |
68.5% |
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Multiple pregnancy (identical twins) |
2 |
| IVF – Own Egg, < 40 years of age |
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Number of cycles |
41 |
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Clinical Pregnancy Rate per transfer |
51.2% |
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Multiple Pregnancy (identical twins) |
1 |
Delivered Pregnancy Rates 2007 (as reported to SART and CDC)
| Oocyte Donation – All |
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Fresh |
Frozen |
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Number of Cycles |
161 |
180 |
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Delivered Pregnancy Rate per transfer |
61.5% |
31.1% |
| IVF – Own Egg |
|
Age |
<35 |
35-37 |
38-40 |
41-42 |
>42 |
|
Number of Cycles |
190 |
165 |
199 |
109 |
78 |
|
Delivered Pregnancy Rate per transfer |
44.1% |
42.4% |
23.5% |
22.2% |
10.9% |
More On: IVF - In Vitro Fertilization, PFC Doctors & Specialists, PGD - Preimplantation Genetic Diagnosis, PGS - Preimplantation Genetic Screening Posted in Science Pulse | No Comments »
Thursday, January 15th, 2009
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Joe Conaghan, PhD, HCLD is internationally recognized for his work with human embryos and brings nearly two decades of experience in human embryology to the Pacific Fertility Center.
More about Dr. Conaghan
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| Participants in a workgroup. |
Practicing micromanipulation |
On November 8 th and 9 th, 2008, PFC held a training course for embryologists interested in learning the techniques associated with Preimplantation Genetic Diagnosis (PGD).
The course was organized in conjunction with the Genetics and IVF Institute (GIVF) of Fairfax, Virginia and was originally scheduled to run on the Sunday only. However, due to the overwhelmingly positive response to attend the course, PFC decided to offer the course on Saturday as well. Forty seven individuals heard excellent lectures over the 2 day period.
Dr Dagan Wells from Oxford, UK and Dr Alan Thornhill from London, UK, gave talks on current and future technologies for genetic testing on embryos. Participants were then divided into 4 working groups that spent the rest of the day rotating between activities. The activities included embryo biopsy training, cell fixation training, media and solution making and PGD troubleshooting. Lauri Black, MS, CGC, a Certified Genetic Counselor at California Pacific Medical Center and Mary Sands of GIVF gave talks on genetic counseling. The course also allowed embryologists from all over the world to view the new state of the art laboratory at PFC.
Joe Conaghan, PhD, HCLD
More On: New Innovation, PGD - Preimplantation Genetic Diagnosis Posted in From Us To You | 7 Comments »
Sunday, February 10th, 2008
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Dr. Carolyn Givens worked with thousands of in vitro fertilization patients over the last decade using a combination of attentive, personal care and advanced medical technology.
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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.
More On: ICSI, IVF - In Vitro Fertilization, PGD - Preimplantation Genetic Diagnosis, PGS - Preimplantation Genetic Screening, Treatment Options Posted in From Us To You | No Comments »
Friday, January 4th, 2008
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Dr. Philip Chenette is rated as one of the “Best Doctors in America”, recognized by the Consumers’ Checkbook “Guide to Top Doctors” and is featured in America’s Guide to American’s Top Obstetricians and Gynecologists.
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Every year, several Pacific Fertility Center professionals participate in ASRM’s national meeting. They evaluate the research and share their findings with PFC and Fertility Flash.
Among those attending the conference from PFC were Dr. Philip Chenette and Dr. Isabelle Ryan and Peggy Orlin, MFT. Their reviews cover the following topics: Update #1: Ovarian Stimulation Techniques, Update #2: PGD and Aneuploidy Screening Techniques, Update #3: Egg Freezing, Update #4: Acupuncture, and Update #5: Men and ART.
Update #2: PGD and Aneuploidy Screening Techniques
Preimplantation genetic diagnosis (PGD) has been one of the hallmark technologies of modern reproductive medicine. The ability to look inside a cell, beyond its visual appearance to the actual genes controlling the cell, has provided insight into the workings of the embryo and a valuable clinical tool to improve fertility care.
The most common use of PGD is to count chromosomes using FISH probes. Using labels that glow under ultraviolet light, a limited number of chromosomes can be identified and counted. Missing or duplicated chromosomes are indicators of abnormalities in the embryo, a condition known as “aneuploidy.” FISH has a significant error rate, and while clinically useful, results must be interpreted with caution.
A new technique discussed at the ASRM meeting is SNP analysis. SNPs are common tags in DNA that can be measured by automated systems. Microarrays of thousands of SNPs have been prepared that provide a clear picture of the chromosome structure of a cell. Microarray-based aneuploidy screening has excellent reliability and accuracy, and holds enormous promise for identifying genetically normal embryos. This study represents the first validated method of analyzing the entire set of chromosomes in a single cell. Stay tuned for more on this exciting technology.
Array CGH uses thousands of very small DNA probes along with computer software to describe the structure of DNA in a single cell. A very sensitive test, it is fast enough to be used during an IVF treatment cycle, and far more accurate than conventional fluorescent probe (FISH) analysis. Array CGH may lead to improved IVF outcomes as embryos containing an error in any chromosome can be detected, which would allow better selection of healthy embryos.
PGD has proven useful for the treatment of recurrent miscarriage. In an analysis of 279 patients with recurrent miscarriage (women who had previously experienced 3-5 miscarriages), researchers in New Jersey found an improved miscarriage rate of 19.5% after PGD versus their 40.9% expected rate.
Philip Chenette, MD
More On: Clinical Trials & Studies, Genetic Testing, Miscarriage, PGD - Preimplantation Genetic Diagnosis Posted in Science Pulse | No Comments »
Saturday, June 11th, 2005
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Joe Conaghan, PhD, HCLD is internationally recognized for his work with human embryos and brings nearly two decades of experience in human embryology to the Pacific Fertility Center.
More about Dr. Conaghan
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Q.
We recently had PGD performed, and it revealed that two abnormal embryos were developing beautifully and two genetically normal embryos had ceased developing. Why would the genetically normal embryos not develop in comparison to the genetically abnormal embryos? Would this be due to egg quality? Would the same results be expected for a future PGD procedure? Is it unlikely that a six-cell embryo that had not developed in two days would result in a pregnancy?
A.
I don’t have all the information needed to give you a complete answer but I’m going to assume that you are a typical IVF patient (in your late 30′s) and were doing PGD to eliminate embryos with chromosomal abnormalities or aneuploidy. During your IVF cycle the eggs that were harvested from your ovaries were inseminated and those that fertilized and continued to develop were analyzed genetically. Depending on your (maternal) age, somewhere around 50% of your eggs would have been genetically abnormal. The genetically abnormal embryos look and behave in the same way as normal embryos.
Most genetic abnormalities cause an embryo to fail at the time of implantation (5 or 6 days old) or cause a pregnancy to fail early (miscarriage). When we look at embryos under the microscope in the days leading up to transfer, there is no way of knowing which are genetically normal or abnormal. Both types of embryos grow and develop similarly. In fact, some embryos that we know are abnormal (e.g. resulting from an egg that is fertilized by 2 sperm) often develop faster and look more beautiful than normally fertilized embryos.
The egg is a very large cell and when it is released from the ovary it has already been programmed to develop for 3 or more days after fertilization. Mom pre-loads her eggs with the necessary information for this early development. In most cells, including sperm, there are internal checks to make sure that the cell is functioning normally and that it is genetically normal. Cells that are abnormal, commit suicide in a process that we call apoptosis. Eggs however, seem to have a very poor internal surveillance mechanism, and even those that are grossly abnormal (e.g. with a whole extra chromosome) can fertilize and develop even to the point of giving you a live child. Down syndrome is the classic example, although at least 75% of embryos affected with this condition miscarry early in pregnancy.
So, eggs are endowed at ovulation with the necessary information to keep them going and looking normal for days, regardless of their genetic constitution. There is no relationship between their genetic status and how beautiful they look in our petri dish. If there were, we wouldn’t need to do PGD. We can keep embryos alive in the laboratory for 5 or 6 days and some of the abnormal embryos might stop developing by that time. However, our experience with PGD over the years tells us that about 50% of the genetically abnormal embryos will still look beautiful on their 5th day of life.
The pattern of development that we see with human embryos, regardless of their genetic status, is extremely variable. As you have witnessed first hand, normal embryos often arrest for reasons that we don’t always understand. This is true, regardless of whether the embryos are growing inside of you or in our lab, and this leads to a very inefficient process of reproduction in human females because she only ovulates one egg per month. We do know that the younger a woman is, the better the chance that the embryo will continue to grow. Embryos are more likely to fail in older women. In very young women, over 50% of embryos will implant in the uterus, but in women over age 40 less than 10% will implant. Although we can’t fully explain this phenomenon, a major contributing factor is egg age. Since women have all the eggs they will ever have when they are born, a 40-year-old woman is trying to get pregnant with a 40-year-old egg. And 40-year-old eggs just don’t perform as well as younger eggs.
Are PGD results consistent from one cycle to the next? The PGD technicians tell me that they get similar results for a patient 2 out of every 3 times.
Any embryo that has not developed in 2 days will not get you pregnant. If an embryo is to be ready for implantation, it must be alive and increasing its cell number every day. We expect a full round of cell division (e.g. from 4 to 8 cells) every 16 hours. Further, an embryo transferred to your uterus on day 4 or day 5, following your PGD analysis, should have enough cells to begin forming a placenta. It sounds like your embryo had arrested (i.e. it was dead).
Human reproduction is a very complex undertaking, and often patients feel like they’re left with more questions than answers after their fertility treatment. Don’t be afraid to ask your questions, no matter how simple or complicated they might be. Chances are, we’ve encountered your situation before.
– Joe Conaghan, PhD, HCLD
More On: Genetic Testing, IVF - In Vitro Fertilization, PGD - Preimplantation Genetic Diagnosis Posted in Ask The Experts | No Comments »
Sunday, June 20th, 2004
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The PFC Staff, as a unified team, is guided by the highest ethical standards. We provide our patients with the best quality, individualized, compassionate fertility care.
More about The PFC Staff
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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.
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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.
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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)
More On: Genetic Testing, IVF - In Vitro Fertilization, Lab, New Innovation, PGD - Preimplantation Genetic Diagnosis, PGS - Preimplantation Genetic Screening, What's New @ PFC? Posted in From Us To You | No Comments »
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| Welcome to InfertilityDoctor.com, blog of Pacific Fertility Center. Located in San Francisco, California, PFC is the leading Bay Area infertility clinic specializing in PGD: preimplantation genetic diagnosis, IVF: in vitro fertilization, egg donor programs, embryo freezing, ICSI & IVF as well as other advanced female and male infertility treatment solutions. Our office is conveniently located near the Bay Bridge and is accessible to those traveling from Bay Area communities such as the East Bay (Berkeley, Oakland, and Walnut Creek), North Bay (Marin and Santa Rosa), Peninsula (San Mateo), and South Bay (San Jose). Our office is also less than an hour-and-a-half from Northern California communities such as Sacramento and Stockton. |
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